YAG Laser in Ophthalmology and Other Selected Indications
Number: 0354
Table Of Contents
PolicyApplicable CPT / HCPCS / ICD-10 Codes
Background
References
Policy
Scope of Policy
This Clinical Policy Bulletin addresses selected indications for YAG lasers.
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Medical Necessity
Aetna considers the following interventions medically necessary:
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Nd:YAG laser capsulotomy when performed following cataract extraction in members with visually significant clouding (opacification) of the posterior portion of the membrane that surrounds the lens (the posterior capsule) according to the following selection criteria based on the clinical guidelines of an expert panel on cataract surgery convened by the Agency for Health Care Policy and Research (AHCPR, 1993):
- After cataract removal in the same eye, unless the laser capsulotomy is scheduled at the same time as cataract removal surgery, or performed prophylactically;
- When performed within 6 months of surgery only if one of the following medical necessity criteria is met:
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The member has a best-corrected visual acuity (BCVA) of 20/50 or worse and both of the following conditions are met:
- The eye examination confirms that posterior capsular opacification is present; and
- The visual impairment has interfered with the member's ability to carry out needed or desired activities; or
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The member has a BCVA of 20/40 or better and all of the following conditions are met:
- The eye examination confirms that posterior capsular opacification is present; and
- Visual disability fluctuates as a result of symptoms of glare or symptoms of decreased contrast; and
- Visual disability has interfered with the member's ability to carry out needed or desired activities; or
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When used for members with posterior capsular opacification regardless of functional impairment for any of the following reasons:
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To provide better visualization of the posterior pole for members with:
- Diabetic retinopathy; or
- Macular disease; or
- Retinal detachment; or
- To diagnose posterior pole tumors; or
- To evaluate the optic nerve head.
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If none of the above criteria is met, Nd:YAG laser capsulotomy performed within 6 months of cataract surgery is considered experimental, investigational, or unproven because of a lack of evidence of the value of routine prophylactic capsulotomy following cataract surgery.
Note: Because posterior capsular opacification is uncommon within 6 months after cataract surgery, requests for Nd:YAG laser capsulotomy performed within 6 months of cataract surgery of the same eye may be subject to medical necessity review.
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Nd:YAG laser peripheral iridotomy for any of the following:
- Acute primary angle closure (APAC); or
- Aqueous misdirection, cilio-lenticular block, ciliary block or malignant glaucoma; or
- Contralateral eye in APAC; or
- Plateau iris configuration and plateau iris syndrome; or
- Primary angle closure and primary angle-closure glaucoma; or
- Primary angle closure suspect (PACS), "narrow" or "occludable" angle; or
- Prior to intraocular lens insertion into the anterior chamber to avoid post-operative iris bombe or pupil block;
- Secondary angle closure with pupillary block;
- Nd-YAG laser goniotomy for the treatment of primary congenital glaucoma;
- YAG laser for the treatment of superficial (extremity, head and neck) venous malformation if conventional therapies (e.g., compression garments, anti-inflammatory medications and analgesics, and low-molecular-weight heparin) have failed;
- Er:YAG laser for diffuse actinic cheilitis without evidence of high-grade dysplasia or cancer on biopsy.
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Experimental, Investigational, or Unproven
Aetna considers following interventions experimental, investigational, or unproven because the effectiveness of these approaches has not been established:
- GentleYAG Laser System for the treatment of venous malformation of the scrotum;
- Laser peripheral iridotomy for pars plana vitrectomy and penetrating keratoplasty;
- Nd:YAG laser peripheral iridotomy for the prevention of pigment dispersion glaucoma;
- Nd:YAG laser goniopuncture for rescue of failed trabeculectomy;
- Nd:YAG laser vitreolysis for the treatment of vitreous degeneration and vitreous floaters;
- Nd:YAG laser anterior hyaloidotomy for the treatment of trapped triamcinolone behind the lens after intra-vitreal injection;
- Nd:YAG laser posterior hyaloidotomy for the clearance of pre-macular hemorrhages;
- Nd:YAG laser for the treatment of the following non-ophthalmological indications (not an all-inclusive list):
- Acne
- Basal cell carcinoma
- Benign prostatic hyperplasia
- Blue rubber bleb nevus syndrome (Bean syndrome)
- Chronic periodontitis
- Cutaneous and palmoplantar warts
- Disc decompression
- Gastrointestinal tumors
- Infantile hemangioma
- Medication-related osteonecrosis of the jaw
- Melasma (low-fluence Q-switched Nd:YAG)
- Nail psoriasis
- Onychomycosis
- Pancreatic cancer
- Peri-implantitis
- Port wine stain
- Recurrent aphthous stomatitis
- Snoring;
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Er:YAG laser for the management of the following non-ophthalmological indications (not an all-inclusive list):
- Debridement in surgical treatment for peri-implantitis
- Genito-urinary syndrome of menopause
- Over-active bladder syndrome
- Polypropylene mesh-induced vaginal erosion
- Prevention of enamel caries
- Psoriasis
- Recurrent aphthous stomatitis
- Reduction of pain, edema, and trismus after removal of impacted mandibular molars
- Urinary incontinence
- Vulvovaginal atrophy;
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Combined Nd:YAG laser with mesenchymal stem cells for the treatment of diabetic wounds.
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Related Policies
Background
The Agency for Health Care Policy and Research (AHCPR) panel concluded that laser capsulotomy should not be scheduled at the time cataract surgery is performed because one can not predict whether a cataract surgery patient will develop posterior capsular opacification or the time at which any such opacification will occur. For similar reasons, manual removal of the posterior capsule, performed with a needle or hook (called corneo-scleral section), should not be routinely performed at the time of initial cataract surgery.
The AHCPR panel also concluded that neodymium:yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy should not be performed prophylactically or scheduled routinely at particular times after cataract surgery.
The eye examination should confirm the diagnosis of posterior capsular opacification and exclude other ocular causes of functional impairment. The panel concurred with the finding of the literature review that there is yet no objective method of relating the degree of capsular opacification to the severity of functional impairment.
The panel also concluded that posterior capsular opacification rarely occurs within 3 months of surgery, and that it is uncommon for posterior capsular opacification to occur within the first 6 months of surgery. Therefore, any cases of Nd:YAG laser capsulotomy occurring within 6 months of cataract surgery should be reviewed, to ensure that Nd:YAG laser capsulotomy is reasonable and medically necessary.
In a single center retrospective study, Delaney and colleagues (2002) determined the effectiveness of Nd:YAG vitreolysis and pars plana vitrectomy in the treatment of vitreous floaters. A total of 31 patients (42 eyes) who underwent 54 procedures (Nd:YAG vitreolysis or pars plana vitrectomy) for the treatment of vitreous floaters were included in the study. Main outcome measures were percentage symptomatic improvement following treatment and incidence of post-operative complications. Statistical analysis was performed using the Fisher exact test. Posterior vitreous detachment was the primary cause of floaters in all 42 eyes with co-existing vitreous veils in 3 eyes and asteroid hyalosis in 2 eyes. Thirty-nine of 42 eyes received Nd:YAG vitreolysis; 38 % found Nd:YAG vitreolysis moderately improved their symptoms while 62 % found no improvement. After an average of 14.7 months follow-up, no post-operative complications were recorded. Fifteen eyes underwent a pars plana vitrectomy, 1 with combined phacoemulsification and posterior chamber implantation and 11 following unsuccessful laser vitreolysis. Pars plana vitrectomy resulted in full resolution of symptoms in 93 % of eyes. One patient developed a post-operative retinal detachment which was successfully treated. The authors concluded that patients' symptoms from vitreous floaters are often under-estimated resulting in no intervention. This paper showed Nd:YAG vitreolysis to be a safe but only moderately effective primary treatment conferring clinical benefit in 1/3 of patients.
Kirwan and Cahill (2011) reported on a case of successful drainage of a large pre-macular hemorrhage using laser photo-disruption of the posterior hyaloid membrane. A 47-year old man presented acutely to the authors' emergency department complaining of a 24-hr history of sudden onset, painless and persistent loss of vision in his left eye. Immediately before noticing this loss of vision, he had been vomiting violently from excessive alcohol intake. The left visual acuity was counting fingers. Dilated fundoscopy of the left eye revealed a large pre-macular hemorrhage that was 14 disc diameters in size. Clotting investigations were normal. A diagnosis of valsalva retinopathy was made and the patient elected to receive a prompt Nd:YAG laser posterior hyaloidotomy as an outpatient. At 1 week follow-up, the hemorrhage had drained completely into the vitreous space revealing a healthy macula and the visual acuity had improved to 6/12 unaided. At 6-month follow-up the left visual acuity stabilized at 6/9 unaided. The authors concluded that Nd:YAG laser posterior hyaloidotomy is an useful outpatient procedure for successful clearance of large pre-macular hemorrhages that offers patients rapid recovery of visual acuity and the avoidance of more invasive intra-ocular surgery. The findings of this case study (with short-term follow-up) needs to be validated by well-designed studies.
In a prospective, randomized, controlled trial, Scott et al (2011) tested the hypothesis that Nd:YAG laser peripheral iridotomy (LPI) significantly reduces the incidence of conversion from pigment dispersion syndrome (PDS) with ocular hypertension (OHT) to pigmentary glaucoma (PG). A total of 116 eyes of 116 patients with PDS and OHT were used in this analysis. Patients were assigned randomly either to Nd:YAG LPI or to a control group (no laser). The primary outcome measure was conversion to PG within 3 years, based on full-threshold visual field (VF) analysis using the Ocular Hypertension Treatment Study criteria. Secondary outcome measures were whether eyes required topical anti-glaucoma medications during the study period and the time to conversion or medication. Fifty-seven patients were randomized to undergo laser treatment and 59 were randomized to no laser (controls). Age, gender, spherical equivalent refraction, and intra-ocular pressure at baseline were similar between groups. Outcome data were available for 105 (90 %) of recruited subjects, 52 in the laser treatment group and 53 in the no laser treatment group. Patients were followed-up for a median of 35.9 months (range of 10 to 36 months) in the laser arm and 35.9 months (range of 1 to 36 months) in the control arm. Eight eyes (15 %) in the laser group and 3 eyes (6 %) in the control group converted to glaucoma in the study period. The proportion of eyes started on medical treatment was similar in the 2 groups: 8 eyes (15 %) in the laser group and 9 eyes (17 %) in the control group. Survival analyses showed no evidence of any difference in time to VF progression or commencement of topical therapy between the 2 groups. Cataract extraction was performed on 1 patient in the laser group and in 1 patient in the control group during the study period (laser eye at 18 months; control eye at 34 months). The authors concluded that the findings of this study suggested that there was no benefit of Nd:YAG LPI in preventing progression from PDS with OHT to PG within 3 years of follow-up.
Ascaso and colleagues (2012) reported on the case of a 65-year old male who underwent intra-vitreal triamcinolone acetonide (IVTA) injection for treating a clinically significant macular edema (CSME) due to background diabetic retinopathy in his left eye. On the first post-operative day, visual acuity dropped from 20/80 to hand movements. Slit-lamp examination showed the drug between the posterior capsule of the lens and the anterior hyaloid face. Two weeks later, visual acuity and the milky fluid seemed unchanged. Neodymium:yttrium-aluminum-garnet laser anterior hyaloidotomy was performed. One week later, slit-lamp examination of the retrolental space revealed the complete disappearance of triamcinolone and intra-ocular pressure remained stable. After a follow-up period of 2 months, visual acuity increased to 20/50 with the lens remaining clear. The authors concluded that Nd:YAG laser anterior hyaloidotomy is an effective, simple, useful and minimally invasive outpatient procedure in patients with persistent entrapment of triamcinolone behind the crystalline lens, allowing the drug to clear without trauma to the lens. The findings of this case study (with short-term follow-up) needs to be validated by well-designed studies.
Ramani et al (2009) examined the morphologic changes in the anterior segment of primary angle closure suspects (PACS) who underwent laser peripheral iridotomy (LPI) for a period of 2 years. Primary angle closure suspects (n = 82 eyes) of Asian Indian origin underwent A-scan biometry and ultrasound biomicroscopy. Anterior chamber depth, anterior chamber angle (ACA), axial length, lens thickness, relative lens position, central corneal thickness, angle opening distance 500, trabecular-ciliary process distance, iris-ciliary process distance, and iris thickness were measured before LPI and after LPI at 1 week, 6 months, 1 year, 1.5 years, and 2 years. Variation in the parameters measured over a period of 2 years was analyzed. Fifteen eyes out of 52 eyes developed into primary angle closure (PAC) with synechial changes. Uni-variate analysis for the predictive factors of PAC showed no significant association for age, sex, narrow angle, ultrasound biomicroscopy parameters, and vertical cup-disc ratio. When analyzed as continuous variables, decreasing ACA was significant risk factor (95 % confidence interval [CI]: 0.703, 0.989, p = 0.037). Iris-ciliary process distance, ACA, lens thickness, and angle opening distance 500 were the parameters that varied significantly (p < 0.05) between "before LPI group" and "after LPI groups". None of the subjects developed increased intra-ocular pressure (IOP) after laser iridotomy. The authors concluded that in this hospital-based study on the course of PACS subjects after LPI, as many as 28 % progressed to PAC. Decreasing ACA was the predictive factor for the progression of PACS to PAC. There was no increase in IOP, history, or symptoms of acute attack of glaucoma among the study subjects after LPI.
In a case-series study, Lin and colleagues (2011) evaluated the long-term changes in anterior segment morphology by using ultrasound biomicroscopy (UBM) following LPI in eyes with PAC. A total of 54 eyes with PAC of 31 consecutive patients were enrolled. Routine ophthalmic and UBM examination were performed at visit-1 (before LPI), 2 weeks, 6, and 12 months after LPI. The parameters of anterior chamber were measured by UBM and calculated. Results of each follow-up time were analyzed using repeated measures analysis of variance. Parameters of UBM measurement at 750 µm anterior to the sclera spur and at 500 µm counterpart were compared using paired student t-test. Compared to before LPI, anterior chamber depth (ACD) was deepened by approximate 0.10 mm after LPI, however, it was not statistically significant (F = 3.50, p > 0.05). Angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA) and trabecular-ciliary process distance (TCPD) were significantly increased at 2 weeks, 6 and 12 months after LPI compared with respective baseline [AOD750: (165.0 ± 70.3), (185.8 ± 68.5), (196.1 ± 77.7) µm versus (66.2 ± 51.6) µm, F = 92.60; TIA750: 14.1° ± 6.3°, 15.5° ± 6.2°, 16.4° ± 5.9° versus 6.4° ± 4.9°, F = 92.60; ARA: (0.058 ± 0.024), (0.065 ± 0.023), (0.068 ± 0.026) mm(2) versus (0.025 ± 0.017) mm(2), F = 92.60; TCPD: (647.1 ± 113.0), (701.8 ± 93.4), (670.1 ± 95.4) µm versus (571.0 ± 97.2) µm, F = 34.00; p < 0.05]. The parameters of UMB measurement at 750 µm were significantly increased more than that at 500 µm anterior to the sclera spur (AOD: t = 5.90, TIA750: t = 2.70, p < 0.05; ARA: t = 2.00, p = 0.05). The authors concluded that LPI can significantly widen the peripheral anterior angle in eyes with PAC lasting for at least 1 year after LPI. Parameters detected by UBM at 750 µm anterior to the sclera spur appear to be more sensitive in evaluating the alternation of peripheral angle structure.
The American Academy of Ophthalmology’s Preferred practice pattern guidelines on “ Primary angle closure” (AAO, 2010) stated that patients with PAC may have elevated IOP as a result of a chronic compromise of aqueous outflow due to appositional or synechial angle closure, or damage to the trabecular meshwork from previous intermittent acute angle-closure crisis. Iridotomy is indicated for eyes with PAC or primary angle-closure glaucoma (PACG).
A Medscape review on “Glaucoma, angle closure, chronic treatment & management” (Tham, 2012) stated that “Laser iridotomy is indicated for all stages of chronic angle-closure glaucoma (CACG). Laser iridotomy involves the creation of a hole in the peripheral iris by laser. The hole provides an alternative pathway for aqueous to flow from the posterior chamber into the anterior chamber, bypassing the pupil. Therefore, iridotomy will eliminate pupillary block and prevent forward bowing of the iris as a result of the pressure difference between the two chambers. Iridotomy will open those areas of the angle not involved by PAS (peripheral anterior synechiae) and prevent further synechial closure”.
Thomas and Walland (2013) noted that PACG and its precursors represent both a significant proportion of world glaucoma blindness and a currently insurmountable burden of treatment. In contrast to primary open-angle glaucoma, preventive interventions in primary angle closure disease (PACD) can sometimes be definitive. These investigators have synthesized data from randomized controlled trials (RCTs) -- and where this is not available -- principles grounded in known biology, biological plausibility, logic, preferred practice and personal experience to develop detailed and explicit clinical algorithms for the management of the spectrum of PACD. Laser iridotomy is the mainstay of first-line intervention and is usually required for all PACD with the exception of some PACS. Laser iridotomy is a necessary but not always sufficient step and uncertainty arises where a patent iridotomy has not alleviated the angle closure profile or achieved clinically desired end points. The crucial step-wise considerations after iridotomy are: whether the angle is open or closed; whether the IOP can be medically controlled; the extent of PAS and the presence of visually significant cataract. These lead to further interventions that include iridoplasty, cataract surgery, trabeculectomy or phacotrabeculectomy. Such subsequent interventions are based on an arbitrary threshold (180 degrees) for angle opening and extent of PAS following iridotomy and other initial procedures.
Susanna et al (2014) stated that there is an increasing need to prolong trabeculectomy success rates with minimally invasive procedures. In a prospective, non-comparative, interventional cohort study, these researchers examined the safety and effectiveness of Nd:YAG laser gonio-puncture (LGP) in IOP in eyes having late bleb failure following trabeculectomy with mitomycin C administration. A total of 19 eyes of 19 patients with uncontrolled glaucoma after failed trabeculectomy were include in this study. All eyes had ischemic non-functioning blebs with patent internal ostia underwent Nd:YAG LGP, followed by a 5-fluorouracil injection. Main outcome measures were IOP and the number of anti-glaucoma medications before and after the procedure, as well as pre-surgical and post-surgical appearance of the blebs, using the Indiana Bleb Appearance Grading Scale classification. The mean (SD) time of LGP after trabeculectomy was 35.7 (32.3) months, and the mean (SD) follow-up period after LGP was 6.0 (1.1) months (range of 4.4 to 8.4 months). The mean (SD) IOP had decreased from 20.9 (4.5) mm Hg (range of 15.5 to 29.0 mm Hg) to 11.9 (4.1) mm Hg (range of 5.0 to 21.0 mm Hg) (p < 0.001). The only complications observed after LGP were 2 cases of hypotony, which resolved spontaneously. Compared with baseline Indiana Bleb Appearance Grading Scale classifications, 2 eyes showed an increase in bleb height and 10 eyes showed an increase in bleb extension. None of the eyes had a positive Seidel test result. The mean (SD) number of hypotensive agents per eye had decreased from 0.7 (1.1) to 0.3 (0.7) after the procedure. At the last follow-up visit, 15 eyes (79 %) had achieved an IOP of 15 mm Hg or less, with a minimum IOP reduction of 20 % from baseline without medication use. The authors concluded that the Nd:YAG LGP is a safe and effective procedure for lowering IOP in eyes with ischemic non-functioning blebs and patent trabeculectomy ostia. They stated that this is a promising solution to rescue failed trabeculectomies and can potentially prolong trabeculectomy success rates.
Guidelines from the World Glaucoma Association (2013) on childhood glaucoma state that angle surgery (goniotomy and trabeculotomy – conventional or circumferential) is the procedure of choice for primary congenital glaucoma with the exact choice dictated by corneal clarity and the surgeon’s experience and preference. The guidelines stated that angle surgery success rates for secondary childhood glaucoma are generally not as good as for primary congenital glaucoma (PCG) with certain exceptions (e.g., glaucoma with acquired condition [uveitis] in juvenile idiopathic arthritis [JIA]).
In a Cochrane review, Ghate and Wang (2015) compared the safety and effectiveness of different surgical techniques for primary congenital glaucoma (PCG). These investigators searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), (January 1982 to June 2014), PubMed (January 1946 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). They did not use any date or language restrictions in the electronic searches for trials. They last searched the electronic databases on June 23, 2014. These researchers included all randomized and quasi-randomized trials in which different types of surgical interventions were compared in children less than 5 years of age with PCG. They used standard methodological procedures specified by The Cochrane Collaboration. A total of 6 trials (4 randomized and 2 quasi-randomized) with 102 eyes in 61 children were included in this analysis. Two trials were conducted in the USA and 1 trial each in Egypt, Israel, Lebanon and Saudi Arabia. All trials included children aged younger than 1 year when diagnosed with PCG, and followed them for periods ranging from 6 months to 5 years. No 2 trials compared the same pair of surgical interventions, so these researchers did not perform any meta-analysis. One trial compared trabeculotomy versus goniotomy; a 2nd trial compared combined trabeculectomy-trabeculotomy with mitomycin C versus trabeculectomy-trabeculotomy with mitomycin C and deep sclerectomy; a 3rd trial compared combined trabeculotomy-trabeculectomy versus trabeculotomy; a 4th trial compared 1 goniotomy versus 2 goniotomies; a 5th trial compared trabeculotomy versus viscocanalostomy; and the 6th trial compared surgical goniotomy versus neodymium-YAG laser goniotomy. For IOP change and surgical success (defined by IOP achieved), none of the trials reported a difference between pairs of surgical techniques. However, due to the limited sample sizes for all trials (average of 10 children per trial), the evidence as to whether a particular surgical technique is effective and which surgical technique is better, still remains uncertain. Adverse events, such as choroidal detachment, shallow anterior chamber and hyphema, were reported from 4 trials. None of the trials reported quality of life or economic data. Overall, these trials were neither designed nor reported well. Two trials were quasi-randomized trials and judged to have high risk of selection bias; 4 trials were at unclear or high risk for performance bias and detection bias; and these investigators judged 1 trial to have high risk of attrition bias due to high proportions of losses to follow-up. Due to poor study design and reporting, the reliability and applicability of evidence remain unclear. The authors concluded that no conclusions could be drawn from the trials included in this review due to paucity of data. They stated that more research is needed to determine which of the many surgeries performed for PCG are effective.
Chronic Periodontitis
The American Dental Association Council on Scientific Affairs Expert Panel’s clinical practice guideline on “The nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts” (Smiley et al, 2015) listed neodymium:yttrium-aluminum-garnet (Nd:YAG) laser and scaling and root planing (SRP) as interventions that were considered but not recommended.
Disc Decompression
Moon et al (2015) noted that laser ablation under an epiduroscopic view allows for the vaporization of a small amount of the nucleus pulposus, causing a reduction in intradiscal pressure and relief of radicular pain. Currently, Ho:YAG and Nd:YAG lasers are commonly used for spinal diseases. However, the use of the Nd:YAG laser for intra-spinal procedures can be limited because of thermal injury and low efficacy. These researchers investigated the safety and effectiveness of epiduroscopic laser ablation using a 1,414-nm Nd:YAG laser; they examined if laser ablation was able to penetrate nucleus pulposus without heating surrounding tissues and without mechanical damage to surrounding tissue. Two live pigs, 3 porcine cadavers, and 2 human cadavers were used. For the in-vitro study, intradiscal and epidural pressure and temperature were compared in vertebral columns obtained from 3 porcine cadavers before and after laser ablation. For the in-vivo study, 2 pigs were used to simulate percutaneous epiduroscopic laser ablation. They were observed for behavioral changes and neurological deficits for 1 month after the laser ablation procedure. Two human cadavers were used for placing the laser fiber and epiduroscope in the correct target site through the sacral hiatus. Histological analysis was also performed to observe any damage around the ablated lesion. Both intradiscal and epidural pressure were markedly reduced immediately after laser ablation as compared with the pre-ablative state. The amount of the pressure decrease in the intradiscal space was significantly greater than that in the epidural space (45.8 ± 15.0 psi versus 30.0 ± 9.6 psi, p = 0.000). The temperature beneath the ipsilateral spinal nerve, which was the nearest site to the laser probe, never exceeded 40° C. Histology revealed no evidence of thermal damage to surrounding structures, including the spinal nerves, end-plates, and vertebrae, after laser ablation. All live pigs showed normal behavior without any sign of pain. In the human cadaveric study, there was no case of targeting failure or dural laceration. The mean time to reach the target region was less than 5 minutes. The authors concluded that the 1,414-nm Nd:YAG laser can be used safely and effectively under the guidance of a spinal epiduroscope in an in-vivo porcine model and in a human cadaveric model. The main drawback of this study was that pressure measurements were performed on cadavers and not in-vivo. Cadaver models cannot account for intradiscal pressure changes that occur during live muscle contraction and different positions, which may affect results. Moreover, although these investigators controlled temperatures with heat baths, vascular and cerebrospinal fluid circulations were not simulated. Those circulations may change the temperature results in-vivo.
Peri-Implantitis
Natto et al (2015) evaluated the effectiveness of various types of lasers (Nd:YAG, carbon dioxide [CO2], diode, erbium/chromium-doped yttrium-scandium-gallium-garnet [Er,Cr:YSGG], and erbium-doped yttrium-aluminum-garnet [Er:YAG]) in the treatment of peri-implantitis and their use in surgical and non-surgical procedures. Human studies for the treatment of peri-implantitis with laser therapy, published between 2002 and January 2014, were collected utilizing the electronic databases PubMed, Ovid, MEDLINE, Cochrane, and Google Scholar. Two reviewers conducted the study selection, data collection, and validity assessment. A total of 812 studies were selected in the initial title search; 13 studies were then chosen for this review. No human studies evaluated the effect of the Nd:YAG laser on peri-implantitis. The CO2 laser was reported to be safe and able to enhance bone regeneration. The diode laser (980 nm) appeared to be effective in its bactericidal effect without changing the implant surface pattern. The Er,Cr:YSGG laser was reported to obtain bone regeneration around a failing implant in 1 case, while the Er:YAG laser exhibited a strong bactericidal effect against periodontopathic bacteria at a low energy level. The authors concluded that although lasers have shown promising results in reducing clinical signs of peri-implantitis, because of the limited sample sizes and short follow-up periods, no firm conclusion can be drawn at this moment. They stated that there is a need for more well-designed, longitudinal, RCTs.
Li and colleagues (2021) stated that erbium-doped yttrium aluminum garnet (ER:YAG) lasers have been used to treat peri-implant; however, there were some disputes. To dispel these negative views, these investigators compared the safety and effectiveness of Er:YAG lasers versus conventional mechanical debridement in the treatment of peri-implantitis. A total of 7 databases were used to search for relevant studies and full-text articles that examined the comparisons of Er:YAG lasers and mechanical debridement for patients with peri-implantitis. Review Manager 5.4 was used to examine the effects of the results among the selected studies. Forest plots, subgroup analyses, and on the included articles were also completed. Cochrane risk of bias assessment tool was used to evaluated the risk of bias. This study focused on 10 previously conducted studies that entailed 294 patients with peri-implantitis and a total of 461 implants. No significant differences in clinical attachment level (CAL) (MD = 0.17, p = 0.25, at 6 months; MD = 0.23, p = 0.15, at 12 months), reduction in bleeding on probing (BOP) (MD = 9.54 %, p = 0.18, at 6 months; MD = 11.28 %, p = 0.24, at 12 months), or plaque index (PI) (MD = -0.02, p = 0.75, at 6 months; MD = -0.07, p = 0.66, at 12 months) were observed between the Er:YAG laser group and the mechanical debridement group. However, in reducing probing depth (PD) (MD = 0.28, p = 0.03, at 6 months; MD = 0.35, p = 0.002, at 12 months) and gingival recession (GR) changes (MD = -0.12, p = 0.04, at 6 months; MD = -0.16, p = 0.03, at 12 months), the Er:YAG laser group showed some advantages at 6-month and 12-month intervals following treatment. No significant publication bias existed in this meta-analysis by using funnel plot and Egger's test (PD: p = 0.65; CAL: p = 0.73). The authors concluded that Er:YAG laser use was superior to mechanical debridement in the treatment of peri-implantitis. Despite this conclusion and due to the limitations of the included studies, longer-term patient follow-ups, with high-quality, multi-center, large-sample RCTs are still needed, and studies that address economic benefit-cost ratios should be included to confirm the effectiveness of Er:YAG lasers in the treatment of peri-implantitis.
The authors stated that this meta-analysis had several drawbacks. First, an insufficient sample size may have led to the lack of statistical differences. Second, the inclusion criteria for each study were different. Third, the treatment designs of each trial were not completely identical, with 3 trials combining surgical and non-surgical treatments. The brand and surface structure of the implant would affect bone re-bonding effects, which would affect the final results. Fourth, there was no description of an economic benefit-cost ratio in any of the included studies.
In a systematic review of RCTs, Li et al (2023) examined the effectiveness of Er:YAG laser (ERL) as a debridement method in surgical treatment of advanced peri-implantitis. These investigators carried out an electronic database search and a manual search until March 2022. Outcome measures were clinical attachment level (CAL) gain, probing depth (PD) reduction, plaque index (PI) and bleeding on probing (BOP). The addressed PICO question was: Is ERL an effective debridement tool in the surgical treatment of advanced peri-implantitis? A total of 5 eligible RCTs were included in the qualitative analysis, 1 of which had unclear risk of bias; 1 study reported a statistically significant difference in terms of implant CAL gain and PD reduction in favor of the experimental group versus the control group, while 4 did not report any difference between the 2 groups. The authors concluded that as a consequence of methodological heterogeneity, such as non-standard control groups and laser parameters, this systematic review showed inconclusive findings in terms of the effectiveness of Er:YAG laser as a debridement method in surgical treatment of advanced peri-implantitis. The results of this review should be considered preliminary and further, well-designed studies with standardized comparators with laser parameters are needed.
Urinary Incontinence
Ogrinc et al (2015) assessed the non-invasive erbium:yttrium-aluminum-garnet (Er:YAG) laser as a potential treatment strategy for stress urinary incontinence (SUI) and mixed UI (MUI). These researchers included 175 women (aged 49.7 ± 10 years) with newly diagnosed SUI (66 % of women) and MUI (34 %), respectively. Patients were clinically examined and classified by incontinence types (SUI and MUI) and grades (mild, moderate, severe, and very severe) using International Consultation on Incontinence Modular Questionnaire (ICIQ) and assessing Incontinence Severity Index (ISI). Using Er:YAG laser, these investigators performed on average 2.5 ± 0.5 procedures in each woman separated by a 2-month period. At each session, clinical examination was performed, ICIQ and ISI assessed, and treatment discomfort measured with visual analog system (VAS) pain scale, and adverse effects and patients' satisfaction were followed. Follow-ups were performed at 2, 6, and 12 months after the treatment. After the treatment, ISI decreased for 2.6 ± 1.0 points in patients diagnosed with mild UI before the treatment, for 3.6 ± 1.4 points in those with moderate UI, for 5.7 ± 1.8 points in those with severe UI and for 8.4 ± 2.6 in those with very severe UI (p < 0.001, paired samples t-test). Altogether, in 77 % patients diagnosed with SUI, a significant improvement was found after treatment, while only 34 % of women with MUI exhibited no UI at 1-year follow-up. Age did not affect the outcome. No major adverse effects were noticed in either group. The authors concluded that the findings of this study showed that new non-invasive Er:YAG laser could be regarded as a promising additional treatment strategy for SUI with at least 1 year lasting positive effects. On the other hand, it does not seem appropriate for treating MUI.
In a pilot study, Fistonic et al (2016) evaluated the safety and effectiveness of the Er:YAG laser for the treatment of SUI. The subject of this study is a treatment of SUI with a 2,940-nm Er:YAG laser, operating in a special SMOOTH mode designed to increase temperature of the vaginal mucosa up to maximally 60 to 65 °C without ablating the epidermis. Numerical modelling of the temperature distribution within mucosa tissue following an irradiation with the SMOOTH mode Er:YAG laser was performed in order to determine the appropriate range of laser parameters. The laser treatment parameters were further confirmed by measuring in-vivo temperatures of the vaginal mucosa using a thermal camera. To investigate the clinical safety and effectiveness of the SMOOTH mode Er:YAG laser SUI treatment, a pilot clinical study was performed. The study recruited 31 female patients suffering from SUI; follow-ups were scheduled at 1, 2, and 6 months post-treatment. ICIQ-UI questionnaires were collected as a primary trial end-point. Secondary end-points included perineometry and residual urine volume measurements at baseline and all follow-ups. Thermal camera measurements have shown the optimal increase in temperature of the vaginal mucosa following treatment of SUI with a SMOOTH mode Er:YAG laser. Primary end-point, the change in ICIQ-UI score, showed clinically relevant and statistically significant improvement after all follow-ups compared to baseline scores. There was also improvement in the secondary end-points. Only mild and transient adverse events and no serious adverse events were reported. The authors concluded that the findings of this study indicated that non-ablative Er:YAG laser therapy is a promising minimally invasive non-surgical option for treating women with SUI symptoms. These preliminary findings need to be validated by well-designed studies.
Benign Prostatic Hyperplasia
In a retrospective observational study, Palmero-Martí and colleagues (2017) compared the safety and effectiveness of thulium laser (Tm: YAG) 150W against greenlight laser (LBO:ND-YAG) 120W in the treatment of benign prostatic hyperplasia (BPH) 12 months after surgery. Subjects were men who underwent the surgical technique of prostate vaporization over a period of 4 years in the authors’ center. The homogeneity of the sample was checked, and post-operative complications (acute urinary retention, re-entry, need for transfusion), failures per year of surgery (re-operation, peak flow less than 15ml/sec, no improvement in comparing the International Prostate Symptom Score (I-PSS)), and decreased prostate-specific antigen (PSA) were compared a year after surgery. A bivariate analysis using Chi-square and t-Student was carried out. A total of 116 patients were treated with thulium and 118 with green laser. The sample was homogeneous for pre-operative variables (p > 0.05). No differences in complications were observed: in urine acute retention, 4.3 % with thulium and 6.8 % with green laser (p = 0.41); in readmissions, 2.6 % with thulium and 1.7 % with green laser (p = 0.68); in need for transfusion, 2.6 % with thulium and 0 % with green laser (p = 0.12). No differences were observed in the percentage of patients re-operation (1.7 % in the group of thulium, 5.1 % in the green laser, p = 0.28); or in individuals with Qmax less than 15 ml/sec (6.9 % with thulium, 6.77 % with green laser, p = 0.75), or in the absence of improvement in the IPSS (5.2 % with thulium, 3.4 % with green laser, p = 0.65). There was also no difference in the levels of PSA in ng/ml a year after surgery: with thulium 2.78 ± 2.09 and with green laser 1.83 ± 1.48 (p = 0.75). The authors concluded that prostate vaporization with thulium laser 150W was comparable to that made with green laser 120W for the treatment of lower urinary tract symptoms caused by BPH, being both safe and effective techniques to 12 months after surgery. Moreover, they stated that future prospective randomized studies are needed to confirm this conclusion on both techniques.
Infantile Hemangioma
Chinnadurai and associates (2016) reviewed studies of laser treatment of infantile hemangioma (IH). These investigators searched multiple databases including Medline and Embase from 1982 to June 2015. Two investigators independently screened studies against pre-determined criteria and extracted key data. Investigators independently assessed study risk of bias and the strength of the evidence of the body of literature. They identified 29 studies addressing lasers: 4 RCTs, 8 retrospective cohort studies, and 17 case series. Lasers varied across studies in type, pulse width, or cooling materials. Most comparative studies (n = 9) assessed variations of pulsed dye laser (PDL) and examined heterogeneous end-points. Most studies reported on treatment of cutaneous lesions. Overall, longer pulse PDL with epidermal cooling was the most commonly used laser for cutaneous lesions; Nd:YAG was the most commonly used intralesionally. Most studies reported a higher success rate with longer pulse PDL compared with observation in managing the size of IH, although the magnitude of effect differed substantially. CO2 laser was used for subglottic IH in a single study, and was noted to have a higher success rate and lower complication rate than both Nd:YAG and observation. Studies comparing laser with β-blockers or in combination with β-blockers reported greater improvements in lesion size in combination arms versus β-blockers alone and greater effects of lasers on mixed superficial and deep IH. Strength of the evidence for outcomes after laser treatments ranged from insufficient to low for effectiveness outcomes. Strength of the evidence was insufficient for the effects of laser compared with β-blockers or in combination with β-blockers as studies evaluated different agents and laser types. Studies assessing outcomes after CO2 and Nd:YAG lasers typically reported some resolution of lesion size, but heterogeneity among studies limited their abilities to draw conclusions. The authors concluded that studies of laser treatment of IH primarily addressed different laser modalities compared with observation or other laser modalities. Pulsed dye laser was the most commonly studied laser type, but multiple variations in treatment protocols did not allow for demonstration of superiority of a single method. Most studies reported a higher success rate with longer pulse PDL compared to observation in managing the size of IH, although the magnitude of effect differed substantially. Studies generally found PDL more effective than other types of lasers for cutaneous lesions. When first introduced as a primary treatment for IH, various laser modalities generally offered superior outcomes compared with steroid therapy and observation. In the era of β-blocker therapy, laser treatment may retain an important role in the treatment of residual and refractory lesions.
Onychomycosis
Rivers and colleagues (2017) examined the effectiveness of a 1064-nm Nd:YAG laser for the treatment of onychomycosis in a real-world setting. A single-center retrospective chart review was conducted between 2012 and 2013. A total of 100 consecutive patients with a culture- and/or potassium hydroxide-confirmed diagnosis of onychomycosis were treated at least twice. Baseline and follow-up photographs were taken, and the change in degree of clinical nail involvement of the subject's great toenail was determined by a blinded reviewer using validated planimetry measurement. A total of 199 hallux nails from 100 subjects were assessed. The mean infected area decreased from 53.2 % at baseline to 50.8 % at the end of the study (paired t-test, p = 0.054; Wilcoxon signed rank test, p = 0.006). Degree of nail involvement was statistically significantly associated with amount of improvement; subjects who had the greatest degree of nail involvement improved the most, while those with less severe disease showed a worsening of nail appearance (Kruskal-Wallis test, p < 0.001); 72.6 % of nails that had more than 67 % nail involvement showed statistically significant improvement (χ2 test, p = 0.001). Adverse events (AEs) were limited to mild-to-moderate pain at the time of therapy. A total of 76 subjects were assessed for treatment satisfaction: 60 % were very satisfied with treatment despite limited clinical improvement in some cases. The authors concluded that laser therapy has a very limited positive clinical effect on the appearance of onychomycosis after 2 treatment sessions.
Piccolo and associates (2017) evaluated the effectiveness of long-pulsed 1064-nm Nd:YAG laser in penetrating tissue and targeting the fungal overgrowth in the nail plate. A total of 20 consecutive, unselected patients were enrolled in the study and treated, at intervals of 1 week, for a total of 4 sessions, using a long-pulsed 1064-nm Nd:YAG laser. In each session, 3 passages across each nail plate were performed with 1-min pause between each passage. A special lens for dermatoscopy, connected to a digital camera, was used for dermoscopic images. In 14 patients (70 %; 12 females; 2 males), excellent results were obtained with an important reduction of chromonychia, onycholysis, opacity, longitudinal striae, and jagged proximal edge. Better results were observed in severe cases in the 2-month follow-up visit. The authors concluded that data for treating nail onychomycosis with laser and light therapy appeared to be positive. They stated that the promising findings of this study identified long-pulsed 1064-nm Nd:YAG laser as a possible alternative option for the treatment of onychomycosis; however, increasing subject data, improving study methodology, and output parameters may become an important next step of study in the treatment of nail onychomycosis.
Port Wine Stain
Xing and colleagues (2017) stated that based on the principle of selective photo-thermolysis, 1064-nm Nd:YAG laser has great potential for the treatment of deeper and larger port wine stain (PWS). However, the clinical effectiveness is limited because of the weak absorption of blood to Nd:YAG laser. These researchers obtained the optimal irradiation conditions to effectively destroy vascular lesions with the assistance of PEG-modified gold nano-rods (NRs) to enhance blood absorption of Nd:YAG laser. In this study, PEG-modified gold NRs were prepared by the seeded growth method. Gold NRs after exposure to Nd:YAG laser were characterized using absorption spectra and transmission electron microscope images. The tissue-like phantom containing a glass capillary with blood was prepared and exposed to Nd:YAG laser to investigate the laser energy density and pulse number required for blood coagulation before and after the addition of gold NRs in blood. The results showed that the milli-second Nd:YAG laser irradiation did not result in the shape change of gold NRs. After injection of gold NRs into the bloodstream (4.60 mg/kg), the absorbance of blood at 1064-nm increased 3.9 times. The threshold energy density for the treatment of PWS decreased by 33 % (from 30 to 20 J/cm2). The authors concluded that these findings provided an experimental guide for choosing laser parameters and gold NRs concentration for the treatment of deeper and larger PWS with the assistance of PEG-modified gold NRs in-vivo in the future.
Recurrent Aphthous Stomatitis
Han and colleagues (2016) stated that laser therapy is a promising new treatment for patients with recurrent aphthous stomatitis (RAS). However, the clinical effect and security issue of laser therapy remain controversial. These researchers performed a systematic review to evaluate the clinical effectiveness and security of laser treatment in RAS patients. Five electronic databases were searched (Medline (PubMed), Embase, ScienceDirect, the Cochrane Library, and Web of Science) to identify all studies that were about RCTs, involving the effect of laser therapy in RAS patients. A total of 23 studies were retained for full-text analysis after screening the titles and abstracts of potential articles, but only 10 studies satisfied the inclusion criteria after the full texts were reviewed. The included studies reported a comparison of the effectiveness between the laser treatment and placebo laser therapy (or conventional drug therapy) when managing the RAS patients. Clinical case reports and RCTs about several different types of lasers (e.g., Nd:YAG laser, Er:YAG laser, InGaAlP laser, GaAlAs laser, etc.) were reported in the use for treatment of RAS. The authors concluded that laser therapy has the superiority in relieving ulcer pain and shortening healing time when compared with placebo group or medical treatment group. They stated that the evidence of the retrieved studies is weak; thus, rigorously designed, long-term, randomized, controlled, and large sample-sized clinical trials are needed to confirm the effectiveness of laser on RAS therapy.
- although most of the included studies provided evidence that laser therapy may help in pain relief and promote wound healing, no report was conducted regarding the difference in recurrence rates after positive and placebo treatments,
- most trials did not report their randomization process and whether treatment allocations were conducted. Nevertheless, treatment allocations may be recognized based on the materials and devices used, and
- cost analysis was not performed in this review because no study reported the price of laser therapy.
Nd:YAG Laser for the Treatment of Basal Cell Carcinoma
Jalian and colleagues (2014) stated that basal cell carcinomas (BCCs) have supporting vasculature that serves as a target for vascular selective lasers. These investigators determined the effect of repeated treatment with a combined 585-nm PDL and 1,064-nm Nd:YAG laser on BCCs of superficial and nodular subtypes of varying diameters. A total of 10 subjects with 13 biopsy-proven BCCs received 4 combined PDL and Nd:YAG at treatments 2 to 4 week intervals. None of the BCCs met the criteria for Mohs micrographic surgery. The tumor and 4 mm of peripheral skin were treated using standardized parameters delivered with a 7-mm spot with 10 % overlap. The treated area was excised and evaluated histologically for residual tumor. The primary study end-point was histologic clearance of tumor. The secondary study end-point was blinded investigator assessment of clinical end-point and adverse effects. Approximately 50 % of all tumors showed a complete response to 4 combined PDL and Nd:YAG treatments (n = 7/12, 58 %). When stratified by size, 75 % of all tumors less than 1 cm in diameter (n = 6/8) showed complete response. Tumor histologic types among the complete responders included superficial and nodular BCCs. All subjects with incompletely responding BCCs were on various forms of anti-coagulation, which these researchers hypothesized, may inhibit laser-mediated thrombosis necessary for the clinical effect. Blinded investigator assessment suggested that biopsy related erythema improved with subsequent laser treatments. The authors concluded that combined PDL and Nd:YAG laser was an effective means of reducing tumor burden in patients with BCC and may be a promising, emerging alternative therapy. They stated that factors influencing treatment response included the concomitant use of anti-coagulation; further studies with a larger number of subjects should focus on optimizing treatment parameters to increase treatment efficacy and aim to limit treatment sessions. Also, investigation into the role of anti-coagulation and its effect on the clinical efficacy of vascular lasers, for all clinical indications, is needed.
In a prospective, non-randomized, open-label, clinical trial, Ortiz and associates (2015) determined the safety, clinical, and histological efficacy of pulsed, high-fluence 1,064-nm Nd:YAG laser therapy for the treatment of BCC on the trunk and extremities. A total of 10 subjects with a biopsy-proven BCC less than 1.5 cm in diameter on the trunk or extremities received 1 treatment with a 10 milliseconds (ms) pulsed 1,064 nm Nd:YAG laser. Standard excision was performed 1 month after laser treatment to confirm histologic clearance. The laser treatment was quick and well-tolerated. There was complete histologic clearance after 1 treatment in 92 % of the BCC tumors, overall. At higher fluences, there was 100 % histologic clearance after 1 treatment; no significant AEs were seen, including scarring. The authors concluded that 1,064-nm long-pulsed Nd:YAG laser may offer a safe alternative for treating BCC off the face. Moreover, they stated that a larger study is needed to confirm these preliminary results.
Ortiz and co-workers (2018) have previously conducted a pilot study that showed 100 % histologic clearance at high fluences. Treatments were well-tolerated with no significant AEs. The objective of this larger study was to confirm preliminary results that the 1,064-nm Nd:YAG laser is a safe and effective method for treating non-facial BCC. This was an IRB-approved, prospective, multi-center study evaluating the safety and efficacy of the 1,064-nm Nd:YAG laser for the treatment of BCC on the trunk and extremities. A total of 33 subjects seeking treatment for biopsy-proven BCC that did not meet the criteria for Mohs surgery were recruited. Subjects on current anti-coagulation therapy, or with a history of immunosuppression were excluded. Subjects received 1 treatment with the 1,064-nm Nd:YAG laser as follows: 5 to 6 mm spot, fluence of 125 to 140 J/cm2 and a pulse duration of 7 to 10 ms. Standard excision with 5 mm clinical margins was performed at 30 days after laser treatment to evaluate clinical and histologic clearance of BCC. Standardized photographs and adverse assessments were taken at the baseline visit, immediately after laser treatment and on the day of excision. A total of 31 subjects completed the study; BCC tumors had a 90 % (28 of 31 BCC tumors) histologic clearance rate after 1 treatment with the long-pulsed 1,064-nm Nd:YAG laser. Treatments were generally well-tolerated without any anesthesia. Immediate side effects included edema and erythema. At 1-month follow-up, some patients had residual crusting; no significant AEs occurred. The authors concluded that 1,064-nm long-pulsed Nd:YAG laser is an alternative for treating non-facial BCC for those that were poor surgical candidates.
Furthermore, National Comprehensive Cancer Network’s clinical practice guideline on “Basal cell skin cancer” (Version 1.2018) does not mention laser as a therapeutic option.
Nd:YAG Laser for the Treatment of Gastro-Intestinal tumors
Saccomandi and colleagues (2017) noted that endoscopic submucosal dissection (ESD) is a minimally invasive technique allowing for the removal of early gastro-intestinal (GI) tumors, widely considered as a valid alternative to conventional surgery. However, ESD is technically demanding, and potentially severe complications, such as bleeding and perforation, may occur. Energy-based techniques (e.g., radiofrequency ablation) might offer a potential alternative to ESD. However, their use mandates the ability to predict the damage induced and to identify a "signature" of the complete ablation, without the need for a physical specimen. Ideally, an energy-based procedure should be tunable in order to limit the ablation to the superficial layers, namely mucosa (M) and submucosa (SM), without injuring the muscularis propria (MP), thereby minimizing GI perforation. In this experimental study , these researchers examined thermal damage induced by Nd:YAG laser on the gastric wall, at different laser settings such as power (P) and time (t). Laser ablation was performed on the stomach wall of 6 Wistar rats. Two powers (2.5 W and 1.0 W) and 3 exposure times (12 s, 6 s and 2 s) were tested, for a total of 30 ablations. Histological analysis allowed to assess thermal damage, in terms of damage depth (DD) and identification of involved layers. The ratio (R) between DD and the total depth (TD) of target layers (M + SM) was used as an index to evaluate the effectiveness of laser settings. At P = 2.5 W, MP was damaged (R > 1) in the majority of cases (11/15). At P = 1.0 W, MP was preserved in all tests (R < ;1), and rarely (4/15) did the damage reach the whole SM (R = 1). Histopathological analysis evidenced that tissue damage was strongly related to the variable tissue thickness. The authors concluded that these preliminary results appeared to support the fact that endoscopic tunable laser ablation was feasible with a consistent damage/power correlation. They stated that further tests are needed to optimize the settings for applications on early GI tumors.
Nd:YAG Laser for the Treatment of Nail Psoriasis
Kartal and colleagues (2018) noted that psoriasis is a chronic inflammatory skin disease in which lesions display angiogenesis and increased vascularity. The long-pulsed 1,064-nm Nd:YAG laser treats vascular lesions which suggests that it might also be used to treat nail psoriasis. A total of 16 patients (10 males and 6 females) with isolated nail psoriasis or nail with only mild cutaneous involvement were enrolled in the study. Nails were treated for 3 sessions with long-pulsed 1,064-nm Nd:YAG laser once-monthly. During the course of the treatment, nail bed and matrix Nail Psoriasis Severity Index (NAPSI) scores were recorded. The mean baseline NAPSI score was 26 ± 7.2. The means of total NAPSI scores after the 1st, 2nd, and 3rd treatment sessions were as follows: 22 ± 6.6, 13 ± 6, and 5.7 ± 4.3, respectively. The decline in NAPSI score was statistically significant. At the end of the 3 treatment sessions, both nail bed and matrix lesions significantly responded to Nd:YAG laser treatment. The authors concluded that Nd:YAG laser is a promising therapeutic option for nail psoriasis.
Nd:YAG Laser for the Treatment of Pancreatic Cancer
Di Matteo and colleagues (2018) stated that endoscopic ultrasound (EUS) has become an interventional technique in which a needle may be used as a vehicle to deliver therapeutic agents. Laser ablation (LA) has been used to treat many primary and secondary neoplasms. These researchers evaluated the feasibility of EUS-guided LA for unresectable pancreatic cancer. Patients with a stage IIb to III pancreatic cancer underwent EUS-guided LA. All patients were unresponsive to previous chemo-radiotherapy. The laser ablation was performed by using a 300-μm flexible fiber preloaded on a 22-G fine needle. A 1064-nm wavelength Nd:YAG laser light with different power settings of 2 W for 800 J, 1,000 J and 1,200 J, 3 W for 800 J, 1,000 J and 1,200 J and 4 W for 800 J, 1,000 J and 1,200 J was used. Each patient was treated with a single application of one of these settings. The application time of the power settings ranged from 200 s to 600 s. A total of 9 patients (median age of 74.7 years, range of 55 to 85 years) underwent Nd:YAG LA. The mean size of the focal lesion was 35.4 mm (range of 21 to 45 mm). The ablation area demonstrated by 24 hours computed tomography (CT)-scan, ranged from 0.4 cm3 (for the lower power setting of 2 W/800 J) to a maximum of 6.4 cm3 (for 4 W/1000 J). The procedure was completed in all 9 patients without AEs. The authors concluded that EUS-guided LA was feasible and well-tolerated in patients with unresectable pancreatic cancer. These preliminary findings need to be validated by well-designed studies with larger sample size and long-term follow-ups.
Furthermore, National Comprehensive Cancer Network’s clinical practice guideline on “Pancreatic adenocarcinoma” (Version 3.2017) does not mention laser as a therapeutic option.
Er:YAG Laser for the Treatment of Psoriasis
- laser + topical drug group (L); and
- drug alone group (D).
The psoriatic lesions in both groups were treated with the same topical treatment (calcipotriol ointment). The corresponding psoriatic lesions in the L group received extra 2,940-nm Er:YAG laser irradiation before topical treatment. The photos of psoriatic lesions were taken before each treatment. The final photos were obtained from the patients at the 7th day after the final treatment. Drug alone or in combination with laser Er:YAG both reduced psoriatic lesions. However, with the increase in the number of treatments, increasing differences were observed between the treatment and the control sides. The therapeutic outcomes in the L groups were better than those in the D groups. Psoriasis area and severity index (PASI) scores for 5 cases of both groups were decreased. However, the scores in the L groups were lower than those in the D groups. The authors concluded that the use of 2,940-nm Er:YAG promoted the absorption of topical drugs for psoriasis, improving the therapeutic effect.
Ramez and co-workers (2018) noted that psoriasis is a commonly encountered chronic dermatological disease, presenting with inflammatory symptoms in patients. Systemic treatment of psoriasis is associated with several adverse effects, therefore the development of a customized topical treatment modality for psoriasis would be an interesting alternative to systemic delivery. The therapeutic modality explored in this article was the comparative treatment of psoriatic patients using nano-particulated methotrexate in the form of jojoba oil-based micro-emulsion with or without fractional Er:YAG laser. Assessment parameters included follow-up photography for up to 8 weeks of treatment, estimation of the psoriasis severity [TES (thickness, erythema, scales)] score, and histopathological skin evaluation. The prepared methotrexate micro-emulsion was clinically beneficial and safe in treatment of psoriasis vulgaris. The authors concluded that the concomitant use of the fractional laser provided improvement in the psoriatic plaques within shorter time duration (3 weeks compared to 8 weeks of treatment), presenting an alternative topical treatment modality for psoriasis vulgaris.
Er:YAG Laser for the Treatment of Genito-Urinary Syndrome of Menopause
Flint and associates (2019) stated that genito-urinary syndrome of menopause (GSM) is a common condition affecting up to 50 % of post-menopausal women and up to 70 % of post-menopausal breast cancer survivors. Genito-urinary syndrome of menopause is a chronic condition with a significant impact on sexual health and quality of life (QOL). The mainstay of treatment has been with symptomatic relief using topical emollients or lubricants; 2nd-line treatment is with topical vaginal estrogens to restore the physiology of the vaginal epithelium. For some, the latter is not suitable or acceptable. Newer treatments with ospemifene and vaginal lasers have now been introduced. The 2 main types of laser currently used for the treatment of GSM are the fractional micro-ablative CO2 laser and the non-ablative photothermal Er:YAG laser. These investigators presented a study protocol for a multi-center, prospective, non-inferiority, single-blinded, RCT comparing the fractional micro-ablative CO2 laser versus the photothermal non-ablative Er:YAG laser for the management of GSM. These researchers will recruit 88 post-menopausal women across 2 sites who will be randomized to 1 of the 2 laser groups. Participants will all have GSM symptoms and a vaginal health index scale (VHIS) of less than 15. All participants will receive an active treatment. Each participant will receive 3 applications of vaginal laser 1 month apart and will be followed-up at 1 month, 6 months, and 12 months. The primary outcomes will look at all changes of GSM symptoms (dryness, dyspareunia, itching, burning, dysuria, frequency, urgency), UI (if present), and overall sexual satisfaction. Both subjective and objective means will be used to assess participants. The authors concluded that the findings of this trial have the potential to allow clinicians and women suffering from GSM to make an informed decision when opting for a specific laser type. The trial will add to the current growing body of evidence for the safe use of vaginal lasers in GSM as an alternative treatment. These researchers hope this trial will provide robust and long-term data for the safe use of both lasers.
Guidelines from the North American Menopause Society on management of genitourinary syndrome of menopause in women with or at high risk for breast cancer (Faubion et al, 2018) state: "Although large, sham-controlled, RCTs have not been completed to date in women with or without breast cancer, one is planned (IBC Alliance trial). Available data suggest the VEL [vaginal Erbium YAG laser] or CO2 lasers have the potential to ameliorate distressing GSM for survivors of breast cancer without the need for local hormone intervention. Placebo or active-controlled trials, long-term safety follow-up, and additional economic analyses are needed."
Er:YAG Laser for the Treatment of Over-Active Bladder Syndrome
Okui and colleagues (2019) examined the safety and efficacy of non-ablative vaginal Er:YAG laser (VEL) for the treatment of over-active bladder (OAB) syndrome compared with those of 2 other common pharmacotherapies (i.e., anti-cholinergics and β3-adrenoceptor agonists). Women aged 60 to 69 years who presented with symptoms of OAB syndrome from 2015 to 2017 were assigned to 3 groups (n = 50) receiving treatment with an anti-cholinergic agent (4-mg fesoterodine), a β3-adrenoceptor agonist (25-mg mirabegron), or VEL (20 min/session of VEL performed thrice). The OAB syndrome symptom score (OABSS), VHIS, and occurrence of AEs were examined before and at 1 year after treatment initiation. The 3 groups showed significant improvement (p < 0.001) for all items of the OABSS questionnaire. Improved VHIS scores were observed only in the VEL group. Furthermore, after VEL treatment, a negative correlation was observed between questions 3 (urinary urgency) and 4 (urgency UI) of the OABSS and VHIS. Regarding safety, no AEs were observed in the VEL group. However, subjects in the other 2 groups complained of constipation, as indicated by the Constipation Assessment Scale scores, and mouth dryness. The therapeutic effects were inadequate for 1 and 2 subjects in the VEL and β3-adrenoceptor agonist groups, respectively. The authors concluded that the use of VEL, anti-cholinergics, and β3-adrenoceptor agonists improved OAB syndrome; VEL exhibited a favorable safety profile (no AEs) and possibly involved a different mechanism of action to that observed following the administration of drugs. These researchers stated that VEL may be a novel therapeutic option for OAB syndrome.
The authors stated that this study had several drawbacks. First, this study was conducted at a single hospital and the patients were observed by a single doctor. Second, the pill counts were not used. These led to the study being assessed as that with poor objectivity. Third, there was no placebo arm in the study. To compensate for this, every patient received exactly equal education. Fourth, the education program may have affected the results.
Nd:YAG Laser for the Treatment of Cutaneous and Palmoplantar Warts
Nguyen and co-workers (2016) stated that although cutaneous warts are common lesions, full remission is not always achieved with conventional therapies. Laser modalities including CO2, Er:YAG, PDL, and Nd:YAG have been examined as alternative treatments for warts. These investigators reviewed the use and efficacy of lasers for treating non-genital cutaneous warts. Published RCTs, cohort studies, case series, and case reports involving laser treatment of non-genital warts were retrieved by searching PubMed with no date limits. Quality ratings of studies were based on a modified version of the Oxford Centre for Evidence-Based Medicine scheme for rating individual studies. A higher emphasis was placed on RCTs and prospective cohort studies with large sample sizes and detailed methodology. There were 35 studies published between 1989 and 2015 that comprised an aggregate of 2,149 patients. Simple and recalcitrant non-genital warts treated with lasers show variable response rates (CO2 laser, 50 % to 100 %; Er:YAG laser, 72 % to 100 %; PDL, 47 % to 100 %; and Nd:YAG laser, 46 % to 100 %). Current RCTs suggest that PDL is equivalent to conventional therapies such as cryotherapy and cantharidin. Combination therapies with lasers and other agents including bleomycin, salicylic acid, and light-emitting diode have shown some success. The authors concluded that lasers could be an effective treatment option for both simple and recalcitrant warts. The lasers most studied for this purpose were CO2, PDL, and Nd:YAG, and of these, PDL has the fewest AEs. These researchers stated that the use of lasers for wart treatment is limited by lack of established treatment guidelines. They stated that future studies are needed to compare laser modalities with each other and with non-laser therapeutic options, and to establish optimal treatment protocols.
Ghonemy and colleagues (2017) noted that treatment for recalcitrant plantar warts remains a continuing challenge as therapeutic options have differing levels of success. These researchers compared the efficacy of 1 % cantharidin, 20 % podophylline resin and 30 % salicylic acid (CPS) versus long-pulsed Nd:YAG laser in the treatment of recalcitrant plantar warts. This study included 30 patients with single or multiple recalcitrant plantar warts; patients were assigned to 1 of 2 groups: the 1st group included 15 patients with 71 recalcitrant plantar warts who were treated by long-pulsed Nd:YAG laser (group I); and the 2nd group included 15 patients with 78 recalcitrant plantar warts who received CPS (group II). The diagnosis of plantar warts was made by clinical examination; 14 patients (93 %) were completely cleared of their warts with topical CPS, while 11 patients (73 %) showed complete clearance with long-pulsed Nd:YAG laser with statistically significant difference between the 2 groups. The authors concluded that topical CPS was safe and effective and represented a promising therapeutic modality than long-pulsed Nd:YAG laser in the treatment of recalcitrant plantar warts.
Shrestha and Karn (2018) stated that despite multiple therapeutic options, there is no consensus on a particular treatment modality in warts. Previous studies have reported safety and efficacy of long-pulsed Nd:YAG laser, with clearance rates higher than those achieved with other therapies. This study was designed to evaluate the efficacy of long-pulsed Nd:YAG laser in the treatment of warts in Nepal. A total of 40 cases of common warts over hands and feet were enrolled in the study. Patients with less than 10 lesions were chosen. Up to 3 sessions of 1,064-nm Long pulse Nd:YAG treatment were done, at the interval of 1 month. No concomitant topical or other treatment was done. Of the 40 patients, 4 were lost to follow-up. Among 36 patients, 8 patients (22 %) achieved clearance of warts in single session, while 12 (33 %) patients and 6 patients (16 %) improved after 2nd and 3rd sessions of laser, respectively. These researchers observed a 72 % clearance rate after 3 sessions of lasers. Adverse effects were pain during treatment and scarring in few patients. The authors concluded that long-pulsed Nd:YAG was effective in the treatment of verruca. However, pain and tissue damage were the limitations. These researchers suggested that long-pulsed Nd:YAG lasers are effective in recalcitrant cutaneous and palmoplantar warts. These preliminary findings need to be further investigated.
Guidelines from the British Association of Dermatologists guidelines on cutaneous warts (Sterling, et al., 2014) noted that CO2 laser, neodymium‐doped yttrium aluminim garnet (Nd:YAG), Er:YAG, infrared and potassium titanyl phosphate laser have also been used in a small number of cohort studies. The guidelines noted that the largest of these (citing Han, et al., 2009) reported a 96% clearance rate of recalcitrant common, palmoplantar and periungual warts in 369 patients treated with Nd:YAG laser.
YAG Laser for the Treatment of Superficial (Extremity, Head and Neck) Venous Malformation
Glaessl et al (2001) noted that three-dimensional (3-D) imaging using CT or magnetic resonance imaging (MRI) data is well known for surgical planning of complex lesions in neurosurgery. In dermatology, percutaneous and intra-lesional Nd:YAG laser therapy is well-established for numerous types of vascular malformations. Diagnostic imaging using US, CT, or MRI is necessary to plan the laser therapy of those malformations. The therapeutic problem is to localize the venous malformation exactly before treatment on sectional 2-D images. These researchers described a 27-year old woman with a venous malformation (VM) of the neck. The data of diagnostic MRI were used for a 3-D reconstruction of the VM to demonstrate the anatomical extent and subcutaneous involvement for laser surgical planning. Percutaneous and intra-lesional laser therapy was performed at 3-month intervals with the Nd:YAG laser using the 3-D reconstruction as a road map for the Nd:YAG laser. Eight weeks after the last laser treatment, the bulky lesions of the neck showed regression. Using the 3-D reconstruction for laser surgical planning, physicians could perform intra-lesional laser treatment more exactly. The complex anatomy of the VM could be elucidated by studying the 3-D images before and during laser surgery. The authors concluded that the use of MRI-based 3-D reconstructions for laser surgical planning could demonstrate the often unexpected extent and improve the intra-lesional laser therapy in the treatment of VMs.
Ulrich et al (2005) stated that hemangiomas and vascular malformations are the most common vascular lesions of infancy. Different lasers can be used for treatment. Nd:YAG laser photocoagulation is particularly effective because of its deep penetration into tissue. A total of 31 patients, aged from 3 months to 18 years, with voluminous hemangiomas and VMs were treated with a cw-Nd:YAG laser. The quartz fiber was used in percutaneous and intra-lesional technique. Long-term follow-up data were acquired by clinical control or a patient questionnaire for a maximal period of 8 years; 20 patients could be evaluated. In the group with hemangiomas (n = 15), 3 cases showed nearly complete remission (CR; greater than 90 %), 10 cases had a partial reduction in size (50 to 90 %), in 1 case there was stable disease (SD) and in 1 case tumor growth. In the group with VMs (n = 5) 2 cases showed an excellent response (greater than 90 %), 1 case a moderate response (25 to 50 %) and in 2 cases there was no improvement; AEs included scars (40 %), hyper- and hypo-pigmentation (23 %), mild atrophy (20 %) and a wrinkled texture (17 %). After maximal reduction in size, 30 % of the patients were not satisfied with the laser treatment outcome and elected surgical excision of the residual lesion. The authors concluded that Nd:YAG laser with percutaneous or intra-lesional application technique was a valuable tool for selected patients with hemangiomas and VMs.
Scherer and Waner (2007) noted that Nd:YAG laser therapy for VMs of the head and neck is a new therapeutic option in addition to sclerotherapy and surgery. A total of 146 patients (aged 2 months to 77.5 years) with VMs in the head/neck (localized, diffuse, and multi-focal) were retrospectively analyzed with regard to number and quality of treatments and laser parameters used. Of these patients, 72 had no prior treatment of any kind, and 74 were pre-treated. Laser treatment of mucosa and tongue was done with a mean fluence of 103.1 J/cm(2), of skin with 90.7 J/cm(2), and of glomuvenous malformations with 81.2 J/cm(2). Complex VM can mostly be controlled but rarely cured. The authors concluded that initial Nd:YAG laser therapy was important in the treatment of VMs regarding shrinkage of the tissue, discoloration, and induction of the desired dermal fibrosis that facilitated the surgical handling of the skin and reduced the risk of skin loss in surgery and sclerotherapy.
In a prospective study, Ma et al (2007) examined the safety and effectiveness of non-invasive long-pulsed 1,064 nm Nd:YAG laser therapy for superficial VMs. A total of 22 patients, aged 9 months to 67 years, skin types III, with skin superficial VMs were treated with the Nd:YAG laser at fluences of 140 to 150 J/cm2, with 6-mm spot size and double pulse model (pulse width 7 to 8 ms, inter-pulse interval of 20 ms). Contact cooling was used to protect the epidermis. Patients were examined 1 month and 6 months after the last treatment. Results were graded as percent clearance in 5 groups: 0 %, 1 % to 25 %, 26 % to 50 %, 51 % to 75 %, 76 % to 100 %. A total of 22 patients completed the study with maximal 5 treatment sessions. At 6 months after the final session, 76 % to 100 % clearance was observed in 96.3 % of the treated sites, 100 % improvement was observed in 37 % of the treated sites. Pain during treatment was variably perceived by patients. Transient erythema were seen in 8 (38.1 %) patients, but resolved in 1 day to 1 month. None of patients had purpura, permanent pigmentation change and scarring. The authors concluded that non-invasive long-pulsed 1,064 nm Nd:YAG laser was safe and s effective for the treatment of skin superficial VMs and selectively removed superficial vessels; AEs were minimal while ideal cosmetic results can be achieved.
Alcantara-Gonzalez et al (2013) stated that VM represent a localized error in the embryological development of the venous branch of the circulation. The management of VM is complex and challenging. These researchers evaluated the safety and efficacy of combined sequential pulsed dye laser (PDL)-Nd:YAG laser in patients with cutaneous or mucosal VM. A total of 30 patients (aged from 8 to 65 years) with cutaneous or mucosal VM treated with dual wavelength PDL-Nd:YAG laser were retrospectively analyzed. Laser parameters were 10 mm spot size with 10 ms pulse and 8 to 10 J/cm(2) of PDL, followed with a second delay by Nd:YAG with 15 or 20 ms at 35 to 70 J/cm(2); or 7 mm spot size with 10 ms pulse and 5 to 10.5 J/cm(2) of PDL, followed with a second delay by Nd:YAG with 15 or 20 ms at 50 to 100 J/cm(2). Laser sessions were repeated approximately every 2 to 6 months. Air cooling was applied during treatment; 3 dermatologists evaluated treatment effectiveness by means of photographs of the patients before and after laser treatment (scale from 0 to 4). Differences in the degree of clinical improvement between patients with cutaneous or mucosal VM were also assessed; AEs were registered. Patient satisfaction was also assessed in 19 cases (scale from 0 to 10). Mean global improvement was rated as 3.37. Mean improvement in patients with cutaneous VM was 3.35 and 3.38 in patients with mucosal VM. No significant difference between both groups was observed (p = 0.53). Long-lasting side effects included partial epilation of the eyelashes in 1 patient, ulceration in 2 patients and permanent scarring in 3 patients. Mean patient satisfaction was 8.55. The authors concluded that the findings of this study showed that dual wavelength PDL-Nd:YAG laser was effective for the treatment of the superficial component of cutaneous and mucosal VM.
Zheng et al (2013) stated that VM is one of the most common benign vascular lesions, with approximately 40 % of cases appearing in the head and neck. They can affect a patient’s appearance and functionality and even cause life-threatening bleeding or respiratory tract obstruction. The current methods of treatment include surgery, laser therapy (Nd:YAG laser is most commonly used), sclerotherapy, or a combined approach. It should be pointed that lasers can only penetrate 1 to 3 mm; VMs often are much larger and thicker than 3 mm and can never be affected by laser treatment. The treatment of small and superficial VMs is relatively simple and effective; however, the treatment of deep and extensive lesions involving multiple anatomical sites remains a challenge for the physicians. For complex cases, the outcomes achieved with 1 single treatment approach were poor; thus, individualized treatment modalities must be formulated based on the patient’s condition and the techniques available. Comprehensive multi-disciplinary treatments have been adapted to achieve the most effective results. Based on the national and international literature, the authors formulated treatment guidelines for head and neck VMs to standardize clinical practice.
Ma et al (2014) noted that intra-lesional laser therapy for the treatment of VMs has been previously reported for select patient populations. Larger studies, over a wider variety of indications, are needed to better define the potential role of this technology. In the current study, a 12-year, retrospective review of 44 patients who underwent 73 intra-lesional Nd:YAG or diode laser treatments of VMs was performed. The most commonly encountered lesions were VMs (66 %) and the most commonly involved anatomic locations were the head and neck regions (41 %) and lower extremity (39 %). Primary indications for treatment were enlargement (73 %) and pain (52 %). Lesion size was reduced in 94 % of cases after treatment and pain was improved in 91 % of cases. Minor post-operative complications occurred in 16 (36 %) patients. There was no difference in treatment response among various VM subtypes or anatomic locations (p = 0.497, p = 0.866) or in the incidence of complications (p = 0.531, p = 0.348). Age was the only factor associated with an increased risk of complications (odds ratio [OR], 1.034; p = 0.038). The authors concluded that when used in accordance with the suggested guidelines, intra-lesional laser therapy was a safe and effective treatment modality for VMs of varying compositions and locations.
John et al (2016) stated that the conventional treatments for venous lesions of the lip have been excision, cryotherapy, infrared coagulation, and sclerotherapy. These investigators reported the use of a long-pulsed Nd:YAG laser in 31 consecutive patients. At a mean follow-up of 12 months (6 weeks to 3 years), 27 (87 %) had no evidence of recurrence and 1 had a small contracted scar. The treatment was effective for both small and large lesions, and operation or other ablative techniques are no longer indicated, or considerably less relevant.
Behravesh et al (2016) noted that VM is the most common type of congenital vascular malformation. They are present at birth and are often symptomatic, causing morbidity and pain; VMs can be challenging to diagnose and are often confused with hemangioma in terminology as well as with imaging. An accurate clinical history and cross-sectional imaging are critical for diagnosis and for devising management; Nd:YAG laser therapy has been increasingly used when venous lesions are small, located in difficult anatomical situations, and have not responded to other treatments with good control of VMs. These investigators listed the following indications for the treatment of VMs:
Bleeding from below skin to intramuscular or retro-peritoneal hematoma, hematuria, rectal bleeding, hematemesis, hemoptysis, or intracerebral or intra-spinal bleeding
- Disabling pain
- Functional impairment
- Lesions are in close proximity to important structures or obstruct inflow and outflow of important structures
- Lesions are in life-threatening areas or in areas with high probabilities of complications
- Lesions cause excessively adverse hemodynamic effects
- Recurrent thrombosis.
Murphy et al (2017) noted that VMs manifest with pain, bleeding, disability, and disfigurement in a subset of children. There are scant data available on the utility and tolerability of laser surgery for symptomatic or disfiguring non-port-wine stain VMs in children. These researchers determined the utility and tolerability of the 1,064-nm long-pulsed (LP) Nd:YAG laser for treatment of symptomatic or disfiguring VMs in children. They conducted a retrospective review of 29 pediatric patients with non-port-wine stain vascular malformations who were treated with the LP Nd:YAG laser at the authors’ institution. They reported patient characteristics, treatment parameters, outcomes, and complications. Blinded assessment of clinical efficacy revealed good-to-excellent results in 66.7 % of patients treated and poor to fair results in 25 %. The overall rate of complications was 27 %, with minor skin breakdown and blistering being the most common. The authors concluded that the LP Nd:YAG laser was a well-tolerated and effective treatment modality for a variety of non-port-wine stain vascular malformations in children.
Carqueja et al (2018) stated that VMs can be superficial, affecting the dermis and subcutaneous tissue, or deeper, involving muscle or bone. They can occur throughout the whole body, including visceral locations; VM that affect skeletal muscle are more commonly located in the head and neck, followed by lower and upper extremity and thorax. Pain is a very common symptom and can be secondary to several mechanisms, such as local compression, congestion and thrombosis (secondary to venous stasis) or even hemorrhage into adjacent structures. Patients with VMs can also experience functional impairment, swelling and disfigurement, and when located in the gastro-intestinal (GI) tract, chronic anemia due to associated bleeding may occur. Medical treatments for VMs entail compression garments, anti-inflammatory medications and analgesics, low-molecular-weight heparin (LMWH), as well as sclerotherapy, surgical resection or a combination of both if medical treatments provide insufficient control of the symptoms or progression of the lesion. Laser ablation of VMs, though not commonly used, has showed to be a successful option in specific cases, and there are several laser techniques that have been used with different indications (e.g., Nd:YAG and Alexandrite lasers have been successfully used for the treatment of VMs located in the head and neck, as well as superficial malformations.
Nd:YAG Laser Peripheral Iridotomy for the Treatment of Iris Bombe
Iris bombe is a condition in which there is apposition of the iris to the lens or anterior vitreous, preventing aqueous from flowing from the posterior to the anterior chamber. The pressure in the posterior chamber rises, resulting in anterior bowing of the peripheral iris and obstruction of the trabecular meshwork. There is insufficient evidence to support the use of YAG laser for the treatment of iris bombe; especially since this approach is associated with high failure rate.
In a retrospective study, Spencer et al (2001) determined the survival of Nd:YAG laser peripheral iridotomy (LPI) in those patients with angle closure glaucoma and iris bombe associated with uveitis. This trial was performed on 11 patients of the Ocular Immunology Clinic of the Royal Victorian Eye and Ear Hospital; subjects presented with uveitis, iris bombe due to extensive posterior synechiae and angle closure glaucoma. The date of iridotomy and where possible the degree of inflammation were noted, as was the date of failure of the iridotomy. A control group was constructed consisting of 65 patients who presented with acute angle closure glaucoma without a history of uveitis, who underwent Nd:YAG LPI. The survival of the LPIs in the 2 groups was calculated using Kaplan-Meier survival analysis. Median survival was compared using log rank test. In the study group of 11 patients, 28 iridotomies were performed on 15 eyes; of these 28 iridotomies, 17 failed. Using Kaplan-Meier survival analysis the median time to failure was 85 days. In the control group of 65 patients, 66 iridotomies were performed on 66 eyes. None of the iridotomies in the control group failed. There was a significant difference in the survival of the Nd:YAG LPIs (p = 0.00015) between groups. The authors concluded that there was a high early failure rate of Nd:YAG iridotomies in patients with angle closure glaucoma and iris bombe associated with uveitis.
Betts et al (2020) noted that PI may be required in subjects with uveitis to manage iris bombe, seclusio pupillae and primary angle closure glaucoma (PAOG). In a retrospective study, these investigators identified risk factors for failure of both laser and surgical PIs in patients with uveitis and determine survival durations. This trial enrolled subjects with a history of uveitis undergoing YAG laser or surgical PI at Auckland District Health Board over an 11-year period. Failure of PI was defined as loss of patency or recurrence of iris bombe. A mixed effects shared frailty model was constructed with PI nested within eyes nested within patients, to examine time to failure. A total of 131 PIs were performed in 52 eyes of 39 subjects during the study period (111 YAG PIs and 20 surgical PIs). Median age at time of PI was 46.6 years and 60.5 % of subjects were women. HLAB27 positive uveitis was the most common diagnosis (25.6 % of subjects). Median survival time was 70 days for YAG PI and 11.0 years for surgical PI. On multi-variate analysis, younger age at time of PI (hazard ratio [HR] 0.933, p < 0.001) and iris bombe (HR 2.180, p = 0.046) were associated with risk of failure. Surgical PI was associated with a lower risk of failure (HR 0.151, p < 0.001) compared with YAG PI. Glaucoma developed in 19 eyes (36.5 %), of which 13 required glaucoma surgery. The authors concluded that surgical PI had longer survival than YAG PI, and should be considered in subjects presenting with iris bombe and in young subjects with uveitis.
Nd:YAG Laser for the Treatment of Acne
Modena and colleagues (2020) stated that non-ablative and ablative fractional erbium lasers are among the most frequently used resources in dermatology for facial rejuvenation and for treating dermatological disorders. This type of erbium laser can be found at wavelengths of 1,540 or 1,550 nm, which are classified as non-ablative erbium glass, and at 2,940 nm, classified as ablative erbium YAG. Despite the reports of their clinical benefits, few scientific studies have showed the safety and effectiveness of these lasers in the short- or long-term. In a systematic review, these investigators examined the safety, efficacy, and benefits of applying the erbium glass and erbium YAG lasers. They performed a literature search from August to December 2019 regarding studies published in the last 20 years. Randomized clinical trials in humans that examined the safety, efficacy, and benefits of applying the fractional lasers erbium glass and erbium YAG to facial rejuvenation, skin spots, and atrophic acne scars were considered. A total of 338 articles were identified; 76 articles remained after their titles and abstracts were read, and 42 articles were selected after removing the duplicates. After the articles were read in full, 17 of these articles were included in the systematic review (453 patients). The erbium glass and erbium YAG lasers appeared promising in the short-term, with minimal adverse effects; however, the long-term safety and efficacy still present limitations. The authors concluded that future research with better methodological standardization and a follow-up with a longer evaluation period for possible permanent adverse effects is needed to determine the standardization and safety of therapy with erbium glass and erbium YAG lasers.
Nd:YAG Laser for Medication-Related Osteonecrosis of the Jaw
Li and colleagues (2020) noted that the feasibility of laser-assisted treatments of medication-related osteonecrosis of the jaw (MRONJ) remains poorly understood; therefore, these investigators systematically examined their effectiveness. They carried out a comprehensive search of Medline, PubMed, and Embase to find RCTs, case-control studies, and prospective cohort studies that evaluated them. These researchers examined the eligible studies in duplicate, and if possible, conducted a meta-analysis. A total of 10 studies with a low- to high-risk of bias met the inclusion criteria. These investigators found that a comparison of pain scores before and after using visible and infra-red GaAs laser in the low-level laser treatment based on the numerical pain rating scale (mean difference [MD] of 4.28; 95 % CI: 3.62 to 4.93; p < 0.00001), showed that there were significant differences in the amount of pain. The effectiveness of other laser-assisted treatments on the reduction of pain -- for example, Er:YAG laser surgical treatment, and laser-assisted treatment plus platelet-rich plasma, and the effect of other techniques on wound healing of laser-assisted treatments, were uncertain. They found that the results of the studies that were deemed to be high-to-low quality and to have high-to-low statistical power suggested that there may be considerable clinical improvement in MRONJ by using laser-assisted treatment; these researchers cautiously considered that low-level laser treatment may manage pain and symptoms in these patients. Moreover, the authors stated that more randomized studies of good quality and with a low-risk of bias are needed to determine if laser-assisted treatment should be a routine part of management of patients with MRONJ.
Nd:YAG Laser for the Treatment of Snoring
Neruntarat and colleagues (2020) stated that a new, outpatient, non-surgical method using Er:YAG laser for snoring has been reported. In a systematic review and meta-analysis, these researchers examined the effects of this treatment on snoring. Relevant articles (n = 1,548) were searched from various databases from January 1, 2000 to September 2018 including PubMed, Medline, Embase, Cochrane Library, Web of Science, and Scopus and reference lists. Meta-analysis was carried out with RevMan software. Cochran's Q and I2 statistics were used to evaluate heterogeneity. The overall effect was examined using z-tests. A total of 7 studies and 247 subjects treated with 2 to 3 sessions of Er:YAG 2,940 nm laser (long-pulse mode, 10-Hz, fluence 1.6 J/cm2) were included. There was a statistically significant reduction of pooled snoring VAS (mean difference (MD of - 6.89; 95 % CI: - 7.62 to - 6.15). Patient satisfaction rate after laser treatment was 80 % (95 % CI: 70.69 to 89.05) of cases. A widening of the upper airway dimension was revealed; however, changes in apnea-hypopnea index (AHI) and respiratory disturbance index (RDI) were not significantly different. Mean follow-up period was 3 to 36 months. Patients tolerated the procedure well without anesthesia. There were minimal side effects without serious adverse effects. The authors concluded that the Er:YAG laser was shown to be an effective way to reduce snoring without significant AHI or RDI changes; however, multi-center RCTs with long-term outcomes are needed to confirm the benefits of this laser for snoring.
Nd:YAG Laser Peripheral Iridotomy Prior To Intra-Ocular Lens Insertion
The American Academy of Ophthalmology (AAO) EyeWiki on “Anterior chamber intraocular lenses” (Houser, 2020) stated that “A peripheral iridotomy is created prior to lens insertion to avoid post-operative iris bombe or pupil block”.
Erbium:YAG laser for the Treatment of Vulvovaginal Atrophy
Maris and colleagues (2021) noted that for some patients, local hormonal or non-hormonal treatments for genito-urinary syndrome of menopause (SGUM) are contraindicated or insufficiently effective. Different physical therapies such as vaginal laser therapy, radiofrequency (RF) therapy, photo-biomodulation therapy and local injection of hyaluronic acid (HA), autologous fat (lipo-filling) and platelet rich plasma (PRP) have been proposed as alternatives. In a systematic review, these investigators elaborated guidelines for clinical practice regarding the physical therapies proposed for management of vulvo-vaginal atrophy (AVV). They carried out a review of the literature on AVV management with physical therapies using Medline between January 2014 and December 2020. Regarding vaginal laser therapy, there are few RCTs; and no formal conclusions can be drawn. The fractional CO2 laser did not demonstrate its superiority over local estrogen therapy. The Erbium:YAG laser has not been studied in RCTs. The lack of follow-up on the vaginal laser and the series of cases reporting risks of vaginal stenosis or chronic pain do not encourage recommending it as a 1st-line treatment. The literature concerning other physical treatments of AVV is weak concerning the genital area. The authors concluded that CO2 or Erbium:YAG vaginal lasers are not the 1st-line treatment for AVV (grade C). In patients with a contraindication to local hormonal treatments, treatment with vaginal CO2 laser or Erbium:YAG may be considered after information regarding the risks (burn, stenosis, pain) (expert opinion). The other physical treatments of SGUM have to be evaluated.
Er:YAG Laser for Reduction of Pain, Edema, and Trismus After Removal of Impacted Mandibular Molars
da Hora Sales et al (2022) stated that removal of impacted 3rd molars can be associated with complications such as pain, edema, and trismus that could increase the morbidity of the procedure. In a systematic review, these investigators examined if Er:YAG laser is effective in reducing pain, swelling and trismus compared to rotary instruments in removing impacted lower 3rd molars (3Ms). The searches were conducted independently by 2 researchers and the articles were selected according to the inclusion and exclusion criteria previously established. The predictor variable was the study group (Er:YAG laser versus rotary instruments). The main outcome was the analysis of post-operative pain, edema, and trismus after 3M extractions. Data analysis included the risk of bias evaluation (RoB 2 Cochrane) and meta-analysis with random effects I2 based heterogeneity and 95 % CIs. In the initial results, a total of 1,371 studies were found and 6 RCTs were selected to compose this study. A total of 299 lower 3Ms were removed, 126 with the Er:YAG laser, 142 with a drill and 31 with a piezoelectric instrument. The results of this meta-analysis showed that in the laser group there was a significant reduction in edema (1.82 [95 % CI: -3.06 to -0.57] cm (p = 0.004)) and complications (p = 0.0004), a slight reduction in pain after 2 days (p = 0.030) and there was no variation in trismus (p = 0.200) when compared to the drill group. The surgery and/or osteotomy time was shorter in the drill group. Only 1 study presented low risk of bias. The authors concluded that Er:YAG laser has been shown to be effective in reducing edema, pain and complications in impacted lower 3M surgeries. However due to the lack of standardization in Er:YAG laser therapy, new controlled and standardized studies should be carried out with the aim of proving the effectiveness of this therapeutic modality.
Er:YAG Laser for Treatment of Actinic Cheilitis
Ayen-Rodriguez et al (2022) noted that actinic cheilitis (AC) is a chronic inflammation of the lip considered an oral, potentially malignant disorder associated with an increased risk of lip squamous cell carcinoma (SCC) development. Current therapeutic modalities of AC are controversial, and the implications of laser treatment have not been examined via a systematic review design. In a systematic review, these investigators examined the degree of evidence of laser for the treatment of AC in terms of safety and effectiveness. They searched for primary-level studies published before January 2022 through Medline/PubMed, Embase, Web of Science, Scopus and CENTRAL, with no limitation in publication language or date. These researchers evaluated the methodological quality and risk of bias of the studies included using the updated Cochrane Collaboration's tool for assessing risk of bias (RoB-2). A total of 20 studies (512 patients) met the eligibility criteria. Laser therapy showed a complete clearance of AC in 92.5 % patients, with a maximum recurrence rate of 21.43 %, and a very low frequency of malignant transformation to SCC (detected in only 3/20 studies analyzed). Furthermore, cosmetic outcomes and patient satisfaction were described as excellent. The authors concluded that these findings indicated that laser therapy was a highly effective approach for the treatment of AC.
Nd-YAG for the Treatment of Rosacea
Husein-ElAhmed and colleagues (2022) noted that the current scenario and position of laser and light-based therapies (LLBT) in the therapeutic rosacea scheme are lacking evidence-based recommendations and comparisons on effectiveness and tolerability among different devices. In a systematic review and meta-analysis, these investigators compared the effectiveness, acceptability, and tolerability of the pulsed dye laser (PDL) versus other devices. They carried out a literature search in March 2020; 4 domains were analyzed throughout the following 6 outcomes: Spectrophotometer erythema index and percentage of reduction for background erythema, telangiectasia grading scale for telangiectasias, visual analog scale for pain, and physician's assessment and patient's satisfaction for treatment success. The searches yielded 423 potentially relevant studies. After removing the excluded and duplicated records, a total of 12 records were examined for eligibility in the meta-analysis. Erythema (risk ratio [RR]: 0.38; 95 % CI: -0.20 to 0.95), telangiectasias (RR: 0.54; 95 % CI: -0.87 to 1.94), and the treatment success throughout the physician's assessment (RR :1.23; 95 % CI: 0.74 to 2.04) and the patient's satisfaction (RR: 1.15; 95 % CI: 0.73 to 1.82) were not significantly different between PDL and other LLBT. In the pain domain, PDL was as painful as other LLBT (RR: -0.23; 95 % CI: -0.96 to 0.49); but more painful than neodymium: yttrium-aluminum-garnet laser (Nd-YAG; RR:0.84; 95 % CI: 0.53 to 1.14) and less than intense pulsed light (IPL; RR:- 1.18; 95 % CI: -1.56 to 0.80). The authors concluded that this work based on previously published literature demonstrated that the quality of evidence to support any recommendation on LLBT in rosacea was low-to-moderate. Among all the available devices, PDL holds the most robust evidence, although in the meta-analysis the effectiveness was comparable to other LLBT, such as Nd-YAG or IPL.
Li and Wang (2022) stated that the advantage of PDL for the treatment of rosacea is still u clear. In a meta-analysis, these investigators compared the curative effect of PDL to Nd:YAG laser for the treatment of rosacea. They searched PubMed, Embase, and Cochrane Library databases for clinical studies on the effectiveness of PDL for the treatment of rosacea through October 13, 2021, and heterogeneity tests among studies were evaluated. Meta-analysis was carried out to combine the effects of physicians' clinical assessments, patient global assessment, erythema index, and visual analog scale (VAS). A total of 326 articles were obtained from 3 databases and 10 articles were finally included. The clinical improvements of greater than 50 % clearance of up to 68.6 % in the PDL group and 71.4 % in the control group, and the subjective satisfaction rate of patients in the PDL group of 88.6 % compared to 91.4 % in the Nd:YAG group; however, there were no significant differences in the rates of patients with rosacea with clinical improvement (greater than 50 % clearance) (RR = 0.94, 95 % CI: 0.75 to 1.17, p = 0.578) or patient subjective satisfaction rate (RR = 0.96, 95 % CI: 0.70 to 1.33, p = 0.808) between PDL and Nd:YAG groups for rosacea treatment. Furthermore, the pain score for PDL and Nd:YAG were not significant (mean = 3.07, 95 % CI: 1.82 to 4.32, p = 0.115). The authors concluded that the 2 treatments all showed clinical effectiveness and patient satisfaction for the treatment of rosacea, with no significant differences observed between treatments. The pain scores for PDL and Nd:YAG were not significant. Moreover, these researchers stated that considering the limitations of this study, the results of this meta-analysis require verification by RCT with larger samples and higher quality.
The authors stated that this study had several drawbacks. First, the numbers of included studies and sample size were both small. Second, the clinical and methodological heterogeneity of the included literature was relatively large. Third, the examination of publication bias was limited due to the small number of included studies. The inevitable potential publication bias may have affected the robustness of the conclusions. Fourth, it was a pity that these investigators could not carry out a meta-analysis regarding the AEs because only 1 included article reported the relevant AEs following treatment with PDL and Nd:YAG laser. More studies regarding the AEs caused by treatment with PDL and/or Nd:YAG laser need to be performed and more validation is needed to be involved in the further meta-analysis. Finally, the exclusion criteria in this study may have induced a potential applicability limitation: although the method may have resulted in an accurate outcome of using PDL or Nd:YAG only, the absence of other therapy method limited the applicability of these findings. Actually, patients often tend to select several therapy methods rather than only 1 therapy to improve the severity of rosacea in clinical practice.
Consensus recommendations from the American Acne and Rosacea Society state: "Early studies with long-pulsed 532-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser demonstrated efficacy in treating telangiectasia. More recent studies using a more powerful 532-nm laser reported excellent results when treating telangiectasia and diffuse erythema in patients with rosacea, which were comparable to those seen with PDL devices. Importantly, the use of lasers, IPL devices, and PDLs have shown superior results treating telangiectatic vessels compared to results achieved treating diffuse facial erythema of rosacea, although both have shown response".
Nd:YAG Laser for the Treatment of Blue Rubber Bleb Nevus Syndrome (Bean Syndrome)
Maunoury et al (1990) described the findings of 3 patients with "blue rubber bleb nevus syndrome" who presented with recurrent digestive tract hemorrhage. Tuberous angiomas of the digestive tract associated with typical skin lesions as described by Bean led to diagnosis. Endoscopic coagulation with Nd:YAG laser and bipolar electrocoagulation "Bicap" of gastric and colonic angiomas was performed successfully without complication; but did not avoid hemorrhagic recurrence originating from lesions located in the small bowel, as demonstrated during laparotomy in 1 case.
Low-Fluence Q-Switched Nd:YAG Laser for the Treatment of Melasma
Lee et al (2022) stated that melasma is a common pigmentary disorder with a complex pathogenesis, of which the treatment is challenging. Conventional treatment often results in inconsistent results with unexpected pigmentary side effects and high recurrence rates. Recently, the low-fluence Q-switched Nd:YAG laser (LFQSNY) has been employed for the treatment of melasma, especially in Asia. In a systematic review, these investigators reviewed available evidence on LFQSNY treatment of melasma published between 2009 and May 2022 to examine the effectiveness and AEs, including its combination therapy. They carried out a systematic PubMed search and a total of 42 studies were included in this review. It was hard to summarize the heterogenous studies; however, LFQSNY appeared to be a generally safe and effective treatment for melasma considering the results of previous conventional therapies. However, mottled hypopigmentation has been occasionally reported to develop and persist as an AE of LFQSNY, which may be associated with the high accumulated laser energy. When used aggressively, even LFQSNY can induce hyper-pigmentation via unwanted inflammation, especially in darker skin. The authors stated that although few studies have reported considerable recurrence rates 3 months following treatment, unfortunately, there is a lack of long-term follow-up results of LFQSNY in melasma.
The authors stated that this study had several drawbacks. First, these researchers did not limit their review to RCTs, they also included retrospective and non-randomized trials. Thus, a potential bias could not be ruled out. Second, studies reviewed in this study had heterogenous designs with various sample sizes and outcome measures; therefore, it was difficult to compare the results head-to-head. Third, many studies were performed over a short period of time. Long-term data regarding the recurrence rate and AEs were limited. Fourth, these investigators did not focus on the type of melasma. In future studies, a head-to-head comparison using a unified outcome measurement and a time-point to examine the effectiveness is needed, considering long-term data such as recurrence rate and type of melasma.
Chen et al (2022) noted that melasma is considered as a type of acquired facial pigmentary disorder that is challenging to treat. LFQSNY has been reported to provide clinical benefits against melasma; however, there are some disputes. In a systematic review and meta-analysis, these investigators examined the safety and effectiveness of LFQSNY monotherapy and combined therapy for the treatment of melasma. The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for relevant articles from inception to July 2021. The resulting data were analyzed using the Review Manager 5.3 software. A total of 12 eligible studies comprising 358 patients were included. No significant differences in melasma area and severity index (MASI) were observed between the LFQSNY and drug groups (MD: -0.26, 95 % CI: -1.16 to 0.64, p = 0.57). These researchers found that combination therapy with LFQSNY and drugs had a greater MASI improvement compared with LFQSNY therapy alone (MD: 1.78, 95 % CI: 0.93 to 2.63, p < 0.0001); nevertheless, no statistically significant results were found in melanin index (MI) and self-assessment. The melasma improvement was similar when using LFQSNY alone and LFQSNY combined with other lasers in terms of RMASI (MD 0.05, 95 % CI: -0.61 to 0.70, p = 0.56). Compared with IPL alone, LFQSNY with IPL provided an added benefit for melasma severity (MD: 3.23, 95 % CI: 0.65 to 5.81, p = 0.01). Th authors concluded that low-fluence 1064 nm Q-switched Nd: YAG laser could be used as an alternative treatment for drug intolerance. Combination therapy with LQSNY and drugs or other lasers may have pleasantly surprising effectiveness; however, numerous studies are still needed to verify this.
Er:YAG Laser for the Prevention of Enamel Caries
Feng et al (2024) stated that dental caries is a global health problem, and its prevention has become a principal objective of modern dentistry. Laser irradiation is believed to have potential in preventing dental caries. In a systematic review and meta-analysis, these investigators examined if Er:YAG laser irradiation has potential for the prevention of enamel caries. Based on inclusion and exclusion criteria, PubMed, Web of Science, and Embase databases were searched; 2 reviewers independently used these search strategies to review titles and abstracts, with no language or date restrictions, up to June 2023. For the quantitative analysis, continuous variables were analyzed by standard mean difference (SMD) with a 95 % CI. The statistical analyses were carried out using Review Manager and Cochrane Collaboration (2020). A total of 51 potentially eligible studies were identified, of which 16 in-vitro studies were eventually included in the quantitative meta-analysis -- 3 studies showed a low risk of bias, and 13 studies a medium risk of bias. In general, there was no significant difference between the calcium ions released under acidic conditions following laser irradiation. The final results indicated that after Er:YAG laser irradiation, enamel could maintain higher surface micro-hardness in acidic environments, as well as smaller lesion depth, and less mineral loss, demonstrating its potential in preventing enamel caries. However, the effect of laser irradiation on the release of calcium ions in acidic solutions and the surface micro-hardness of demineralized enamel was non-significant; thus, more in-vitro as well as clinical trials are needed in to examine if Er:YAG laser irradiation can effectively prevent enamel caries in the clinical setting.
The authors stated that one of the drawbacks of this systematic review and meta-analysis was that all the included studies were in-vitro studies, which could not fully simulate the conditions in the oral environment. In addition, because dental caries is a multi-factorial disease mainly caused by bacteria, the studies included in this study only addressed the chemical-induced demineralization of enamel, lacking the important influence of bacteria in the caries process. These researchers stated that future studies should aim to simulate the oral environment in order to validate the findings of the current systematic review and obtain clinically relevant information.
Er:YAG Laser for the Treatment for Polypropylene Mesh-Induced Vaginal Erosion
Okui et al (2024) noted that vaginal erosion caused by the polypropylene mesh is a serious side effect, and the development of effective treatment is needed. In a retrospective, case-series study, these researchers examined the potential of non-ablative vaginal erbium YAG laser as a novel therapeutic approach. Erbium YAG laser was carried out on 9 women who experienced vaginal erosion following treatment for pelvic organ prolapse (POP) with polypropylene mesh. These patients visited the authors’ hospital between April and December 2020. Using the Renovalase, the laser was applied to the entire vagina, with intensive irradiation focused on the erosion areas. Detailed analyses of symptoms before and after treatment, as well as histopathological changes, were performed 1 year post-treatment. Subjects’ average age was 73.2 years (range of 69 to 81), with 4 patients having undergone trans-vaginal mesh (TVM) surgery and 5 having undergone laparoscopic sacro-colpopexy (LSC). The average time from mesh insertion to treatment initiation was 7.2 years (range of 3 to 15), with 8 subjects having previously attempted mesh removal. Post-treatment, significant improvements were observed in managing vaginal erosion as well as related bleeding, corroborated by histopathological analysis confirming cell regeneration and tissue repair. These improvements also resulted in significant improvements in bleeding management and QOL. The authors concluded that these findings suggested that erbium YAG laser may be an effective therapeutic approach for vaginal erosion caused by a polypropylene mesh. These investigators noted that the ambiguity of long-term treatment effects, and the lack of direct comparison with other treatments should also be considered when interpreting these findings. Moreover, these researchers stated that further investigations are needed because of the small sample size (n = 9) and the drawbacks inherent in the retrospective, case-series design limiting generalization and causation estimation.
Laser Peripheral Iridotomy
American Academy of Ophthalmology’s EyeWiki on “Laser peripheral iridotomy” (Miguel et al, 2023) noted that LPI is indicated for preventing or overcoming a suspected relative pupillary block by creating an alternative pathway for aqueous flow. Primarily used for patients in the PAC spectrum, it can also be useful in secondary angle closure glaucoma and in the management of other types of glaucoma with associated pupillary block. The iridocorneal angle should be, in all cases, carefully examined following LPI to rule out other mechanisms of a closed angle requiring treatment. The indications for LPI are as follows:
Primary angle closure and primary angle-closure glaucoma
- Acute primary angle closure (APAC)
- Contralateral eye in APAC
- Primary angle closure suspect (PACS), “narrow” or “occludable” angle
- Primary angle closure (PAC) and primary angle closure glaucoma (PACG)
- Secondary angle closure with pupillary block
- Plateau iris configuration and plateau iris syndrome
- Aqueous misdirection, cilio-lenticular block, ciliary block or malignant glaucoma
In a retrospective study, Schranz et al (2024) examined the frequency and anterior segment optical coherence tomography (AS-OCT) parameters of patients with scleral fixated intra-ocular lenses (IOL) and reverse pupillary block (RPB). These investigators searched their records for patients who underwent scleral fixated IOL implantation from January 2018 to February 2023. Patients were included only if there was at least 1 adequate post-operative scan of AS-OCT available. Initially, AS-OCT scans were evaluated for IOL tilt and decentration employing a 3D scan and then later for ACA, aqueous anterior chamber depth (AQD), pupil diameter and iris-IOL distance using the 2D scan at a 0° angle. Both an iris-IOL distance of 0 or less and an ACA of more than 70° were required to define an RPB. A total of 110 patients met the inclusion criteria, 41 were treated using the Carlevale, 33 the 4-flanged, 24 the Yamane, and 12 the Scharioth technique, respectively. RPB was found in 32 patients (29 %) – 20 patients with RPB were treated using YAG peripheral iridotomy, mean ACA decreased from 91.91° ± 13.77 to 61.02° ± 8.52, (p < 0.001), mean AQD decreased from 4.67 mm ± 0.47 to 4.31 ± 0.36 mm (p < 0.001), and mean iris-IOL distance increased from -0.09 ± 0.04 to 0.33 ± 0.30 (p < 0.001). The authors concluded that RPB was found in 1/3 of eyes that had undergone scleral fixated IOL implantation without iridectomy. Moreover, these researchers stated that YAG peripheral iridotomy was a potent option to treat RPB, and subsequently lowered the risk of iris chafing and secondary inflammation or glaucoma.
In a retrospective, comparative, case-series study, Ucar and Sagdic (2025) compared clinical outcomes, RPB findings and anterior segment parameters in patients with and without intra-operative peripheral iridectomy during sutureless flattened flange intra-scleral IOL fixation. This trial included 94 eyes of 82 patients who underwent IOL explantation due to vitreous-dislocated IOL at the authors’ clinic between March 2020 and September 2023, followed by flattened haptic-tipped IOL intra-scleral fixation combined with pars plana vitrectomy (PPV). Subjects were divided into 2 groups: Group 1 (n = 54) underwent peripheral iridectomy during surgery, while Group 2 (n = 40) did not undergo surgical peripheral iridectomy. White-to-white (WTW) distance, ACD, and ACA and were measured BY MEANS OF Scheimpflug imaging. Visual outcomes, ACD, ACA, spherical equivalence (SE), IOP, complications, and secondary interventions were evaluated. There was no significant difference between the 2 groups pre-operatively in terms of IOP, ACD, ACA, WTW distance, and axial length (p > 0.05). Post-operatively, the mean ACD was significantly less in Group 1 (3.79 ± 0.67 mm) than in Group 2 (4.11 ± 0.75 mm) (p = 0.03). Post-operative IOP was 15.51 ± 2.48 mmHg in group 1, and 18.20 ± 4.51 mmHg in group 2 (p < 0.001). The post-operative ACA was statistically significantly shallower in Group 1 (41.72 ± 3.47 degrees) than in Group 2 (52.45 ± 17.93 degrees) (p < 0.001). Post-operatively, RPB developed in 10 eyes (25.0 %) in Group 2, while it was not observed in any patient in Group 1 (p < 0.001). In Group 2, pupillary capture developed in 4 cases (10 %) in addition to RPB. Laser peripheral iridotomy was carried out in cases with RPB; and after LPI, mean IOP, mean ACA and ACD also decreased significantly (p < 0.001). The authors concluded that intra-operative LPI during scleral fixation surgery combined with PPV resulted in significantly less RPB, a more stable anterior chamber, and fewer complications. These investigators stated that LPI was very useful in managing RPB that developed in the post-operative period.
Singh et al (2024) noted that LPI is largely used as the 1st-line treatment of PAC. Previous studies have long been divided on the relationship between iridotomy position and dysphotopsia onset. In a retrospective study, these investigators examined if there is a correlation between iridotomy position (temporal versus superior), and new onset post-operative dysphotopsia rates. This trial entailed a r chart review of 2,385 lasered eyes. Demographic data and iridotomy-specific data including laterality, iridotomy position, and new onset post-operative dysphotopsias were recorded. Of 2,385 eyes with LPIs, 217 (9.10 %) experienced post-operative dysphotopsia. Superior and temporal LPIs were associated with total dysphotopsia rates of 11.20 % and 8.01 %, respectively. The percentage distribution of dysphotopsias among negative, positive, and non-specific categories were 2.81 %, 4.99 %, and 1.26 %, respectively. Superior LPIs were associated with a greater risk of new onset dysphotopsia than temporal LPI (p = 0.0107), specifically negative dysphotopsia (p < 0.0001). The authors concluded that patients with superior LPI were more likely to experience negative dysphotopsia onset than those with temporal LPI. Among negative dysphotopsias, positive dysphotopsias, and non-specific symptoms, only negative dysphotopsias were significantly impacted by iridotomy position. These investigators noted that these findings may influence providers to perform LPI temporally to prevent negative dysphotopsia.
Rothman and Gibbons (2024) examined the cost-utility of prophylactic LPI for PAC suspects (PACS). The Markov model randomized PACS eyes to LPI or observation for 40 one-year cycles (100,000 iterations per strategy). Each cycle, an eye remained in its current health state, advanced linearly through PAC, mild, moderate, severe, and end-stage PAC glaucoma (PACG), or died. Transition rates were derived from the literature including the Zhongshan Angle Closure Prevention (ZAP) Trial and the Singapore Asymptomatic Narrow Angles Laser Iridotomy Study (ANA-LIS). Eyes with acute-angle closure advanced to either PAC or directly to various PACG severities. A tracker monitored accumulated perimetric decibel reduction to progress PACG via increasing severities, with an annual probability of either stable or severity-dependent perimetry loss. These researchers set a willingness to pay of an incremental cost-effectiveness ratio (ICER) of less than $50,000/quality-adjusted life-years. At age 50 years, LPI was cost-saving using ZAP data and cost-effective using ANA-LIS data. The ZAP iterations became cost-effective from the societal perspective when the model started at age 55 years and 3rd-party perspective at age 70 years. LPI was no longer cost-effective from the societal perspective using ANA-LIS data at age 80 years or from the societal perspective using ZAP data or 3rd-party perspective with ANA-LIS data at age 85. Probabilistic sensitivity analyses favored LPI until starting age 85. The authors concluded that prophylactic LPI for PACS is cost-effective across a spectrum of ages and should be considered from a public health perspective.
Shamseldin Shalaby et al (2024) stated that glaucoma is the leading cause of irreversible blindness globally. Among all glaucoma types, PACG affects about 23 million individuals worldwide, and is responsible for 50 % of glaucoma-related blindness. The main mechanism of PACG is relative pupillary block. High-risk populations are female gender, Asian ethnicity, high hyperopia, short axial length, as well as a thick/anteriorly positioned lens. The authors discussed the clinical diagnosis, classification, and management of patients with a narrow angle with and without IOP elevation and glaucomatous optic nerve damage, including LPI, endocycloplasty (ECPL), lens extraction, and goniosynechialysis. These investigators noted that generally, in high-risk PACS, prophylactic LPI should be considered over observation. In PAC and PACG, lens extraction appeared to offer better long-term protection than LPI; however, the management of PAC disease should be tailored based on the underlying mechanism. Those with pure pupillary block may derive the most benefit from LPI, whereas individuals with plateau iris should benefit from low-dose topical pilocarpine, argon LPI, and ECPL. In patients with high lens vault, cataract surgery, with goniosynechialysis if necessary, can improve the angle anatomy, lower the IOP, and lower the number of glaucoma medications. Filtering surgery may be needed in cases of uncontrolled IOP with significant optic nerve damage, either following or combined with cataract surgery.
Sharif et al (2024) noted that PACG is caused by narrowing the iridocorneal angle and increases the risk of blockage in the trabecular meshwork. Phacoemulsification and LPI effectively control IOP elevation and widen the angle. In a systematic review and meta-analysis, these investigators compared phacoemulsification and LPI effectiveness in the treatment of PACG. They searched Medline, Embase, and CENTRAL, and included RCTs that compared phacoemulsification and LPI for individuals with PACG. These researchers sought to examine the following outcomes: mean IOP, number of glaucoma medications, visual acuity (VA), VF progression, peripheral anterior synechiae (PAS), Shaffer gonioscopy grading, central corneal thickness (CCT), central endothelial cell density (CECD), and poor response to surgery. The SMD was used to represent continuous outcomes, while RR was employed to represent dichotomous outcomes. A total of 5 RCTs totaling 917 subjects were deemed eligible. The phacoemulsification group showed statistically significance lower mean CCT and CECD and lower risk of poor response to surgery compared to LPI (SMD = -1.10; 95 % CI: -1.50 to -0.70; p < 0.001, SMD -366.12; 95 % CI: -652.59 to -79.65; p = 0.01, and RR 0.35; 95 % CI: 0.23 to 0.54; p < 0.001 respectively). There were no significant improvement in IOP and number of medications between both groups (SMD = -0.74; 95 % CI: -2.26 to 0.78; p = 0.34, and SMD -17.58; 95 % CI: -50.28 to 15.12; p = 0.29 respectively). Lastly, there were also no significant differences in VA, VF progression, PAS, and mean Shaffer gonioscopy grading between the 2 groups. The authors concluded that phacoemulsification demonstrated statistically significant lower mean CCT, CECD, and lower risk of poor response to surgery compared to LPI. However, there were no significant differences in mean IOP, number of medications, VA, VF progression, PAS, and mean Shaffer gonioscopy grading between phacoemulsification and LPI.
Combined Nd:YAG Laser with Mesenchymal Stem Cells for the Treatment of Diabetic Wounds
In an experimental study, TizMaghz et al (2025) examined the individual and combined effects of low-level laser therapy (LLLT) and human adipose-derived stem cells (hADSC) on wound healing and on biomechanical parameters in type 2 diabetic rabbits. This trial included 40 rabbits with type 2 diabetes (induced by streptozotocin (STZ)). Rabbits were randomly assigned with equal ratios to 4 groups, including the control group (group A), hADSCs alone (group B), the laser alone (group C), and the combined group of hADSCs cells with laser (group D). 30 days after diabetes, 2 wounds were created on the back of each rabbit. Immediately after creating a wound, hADSC was injected into 2 parts of the wound. In the laser groups, the wound site was treated with a low-power 660-nm laser for 4 weeks daily for 20 to 30 s. The number of closed wounds in the treatment group was evaluated 7, 15 and 30 days after the treatment. On the 15th and 30th days, a standard sample of each healing wound was sent for biomechanical evaluation. Thirty days after treatment, the combined effect of LLLT + hADSCs was superior to their individual effects on wound healing and biomechanical parameters (mean bending stiffness, maximum force, high-stress load, and energy absorption), while their individual effects were similar. Fifteen days after treatment, the effect of LLLT alone was superior to hADSCs alone for wound healing and improvement of biomechanical parameters. The authors concluded that LLLT and hADSCs, individually and in combination, were superior in diabetic wound healing and biomechanical parameters compared to the control group in type 2 diabetic rabbits. The combined effect of LLLT with hADSCs was superior to their individual effects. The findings of this experimental study need to be validated in well-designed human studies.
GentleYAG Laser System for the Treatment of Venous Malformation of the Scrotum
In a single-center study, Leavitt et al (2012) discussed their experience with genital vascular anomalies and the management considerations for patients with associated genito-urinary defects. These investigator reviewed the presentation, course, management considerations, surgical treatment, and follow-up of all cases of genital vascular anomalies treated from January 2008 to October 2011. The lesions were classified according to the International Society for the Study of Vascular Anomalies. All subjects were boys aged less than 18 years. These researchers identified 3 patients with genital vascular anomalies -- 2 had an infantile hemangioma and 1 had a venous malformation. All lesions were identifiable on physical examination, and 2 of the subjects presented within a few months of birth. One patient had associated genito-urinary abnormalities that complicated his treatment. Scrotal ultrasonography (US) and pelvic MRI consistently showed the vascular anomalies to be highly vascular and distinct from the underlying testes. Both intra-scrotal lesions were excised, and the cutaneous lesion was excised as a part of a larger genito-urinary reconstruction. At a mean follow-up of 33 months (range of 23 to 42 months), the intra-scrotal infantile hemangioma had recurred, requiring repeat intervention; however, the cutaneous hemangioma had not. The authors concluded that vascular anomalies of the male genitalia are rare. Pelvic MRI was useful for characterizing the internal extent of vascular anomalies and US was useful in monitoring these lesions over time. The timing of surgery and the high recurrence rate were important considerations when planning surgical resection of genital vascular anomalies, especially when associated with concomitant genito-urinary defects.
Edris et al (2024) stated that the main types of scrotal vascular lesions are varicocele, hemangioma, lymphangioma and arterio-venous malformation (AVM). AVM consists of network between arteries and veins without capillaries. It is the rarest type especially when it happens in the scrotum. These investigators described the case of a 24-year-old man who presented with a skin deformity and painless swelling in the left scrotum. Physical examination showed this swelling that extended to the inguinal region. Duplex US (DUS) followed by multi-slice computed tomography (MSCT) were carried out to establish the diagnosis. Management depended on surgical excision without angio-embolization. Pre-operative sperm analysis showed oligoasthenozoospermia that improved significantly after treatment and at 1 year of follow-up. Surgical resection of scrotal AVM without embolization has been used in very few cases and has resulted in a satisfactory outcome with no signs of recurrence throughout the follow-up period. The authors concluded that based on their experience, surgical excision without embolization was a reasonable alternative approach for the treatment of scrotal AVM in low-income countries alongside avoiding the negative consequences of radiation therapy. Treatment should be considered when fertility is affected. Laser was not mentioned as a therapeutic option in this study.
Laser Peripheral Iridotomy for Penetrating Keratoplasty / Pars Plana Vitrectomy
StatPearls’ review on “Penetrating Keratoplasty” (Gurnani and Kaur, 2023) does not mention laser peripheral iridotomy as a management option.
References
The above policy is based on the following references:
- Alcantara-Gonzalez J, Boixeda P, Perez-Garcia B, et al. Venous malformations treated with dual wavelength 595 and 1064 nm laser system. J Eur Acad Dermatol Venereol. 2013;27(6):727-733.
- American Academy of Ophthalmology (AAO). Primary angle closure. Preferred Practice Pattern. San Francisco, CA: AAO; October 2010.
- Ascaso FJ, de Gopegui ER, Cascante JM. Neodymium: yttrium-aluminum-garnet laser anterior hyaloidotomy to treat trapped triamcinolone acetonide behind the crystalline lens after intravitreal injection. Middle East Afr J Ophthalmol. 2012;19(1):163-165.
- Aslam TM, Devlin H, Dhillon B. Use of Nd:YAG laser capsulotomy. Surv Ophthalmol. 2003;48(6):594-612.
- Ayen-Rodriguez A, Naranjo-Diaz MJ, Ruiz-Villaverde R. Laser therapy for the treatment of actinic cheilitis: A systematic review. Int J Environ Res Public Health. 2022;19(8):4593.
- Baratz KH, Cook BE, Hodge DO. Probability of Nd:YAG laser capsulotomy after cataract surgery in Olmsted County, Minnesota. Am J Ophthalmol. 2001;131(2):161-166.
- Behravesh S, Yakes W, Gupta N, et al. Venous malformations: Clinical diagnosis and treatment. Cardiovasc Diagn Ther. 2016;6(6):557-569.
- Betts TD, Sims JL, Bennett SL, Niederer RL. Outcome of peripheral iridotomy in subjects with uveitis. Br J Ophthalmol. 2020;104(1):8-10.
- Carqueja IM, Sousa J, Mansilha A. Vascular malformations: Classification, diagnosis and treatment. Int Angiol. 2018;37(2):127-142.
- Chen J, Yu N, Peng L, et al. Efficacy of low-fluence 1064 nm Q-switched Nd: YAG laser for the treatment of melasma: A meta-analysis and systematic review. J Cosmet Dermatol. 2022;21(7).
- Chinnadurai S, Sathe NA, Surawicz T. Laser treatment of infantile hemangioma: A systematic review. Lasers Surg Med. 2016;48(3):221-233.
- Cinal A, Demirok A, Yasar T, et al. Nd:YAG laser posterior capsulotomy after pediatric and adult cataract surgery. Ann Ophthalmol (Skokie). 2007;39(4):321-326.
- da Hora Sales PH, Barros AWP, de Barros Silva PG, et al. Is the Er: YAG laser effective in reducing pain, edema, and trismus after removal of impacted mandibular third molars? A meta-analysis. J Oral Maxillofac Surg. 2022;80(3):501-516.
- Delaney YM, Oyinloye A, Benjamin L. Nd:YAG vitreolysis and pars plana vitrectomy: Surgical treatment for vitreous floaters. Eye. 2002;16(1):21-26.
- Di Matteo FM, Saccomandi P, Martino M, et al. Feasibility of EUS-guided Nd:YAG laser ablation of unresectable pancreatic adenocarcinoma. Gastrointest Endosc. 2018;88(1):168-174.
- Edris M, Alhomsi D, Harh S, et al. Scrotal arteriovenous malformation (AVM) successfully resected without angioembolization: A case report. Int J Surg Case Rep. 2024;115:109303.
- Faubion SS, Larkin LC, Stuenkel CA, et al. Management of genitourinary syndrome of menopause in women with or at high risk for breast cancer: Consensus recommendations from The North American Menopause Society and The International Society for the Study of Women's Sexual Health. Menopause. 2018;25(6):596-608.
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