1. Aetna considers a comprehensive eye examination or a brief or intermediate examination, and an A-scan medically necessary as a diagnostic test prior to cataract surgery.  Other pre-operative ophthalmologic tests may be considered medically necessary if there is another diagnosis in addition to cataracts.

2. Aetna considers the following specialized ophthalmologic services medically necessary for the routine pre-operative work-up for cataract surgery:

   • Optical coherence biometry
   • Ultrasound, A-scan, diagnostic
   • Ultrasound, A-scan, ophthalmic biometry
   • Ultrasound, with intra-ocular lens (IOL) power calculation.
     

   In addition to a comprehensive or brief/intermediate eye examination, A-mode ultrasound (A-scan) may be considered medically necessary prior to cataract surgery to determine the appropriate pseudophakic power of the IOL.

3. Aetna considers the following specialized ophthalmologic services experimental and investigational for the pre-operative work-up for cataract surgery, unless there is another indication in addition to cataracts, because they are of no proven value in routine pre-operative evaluation of cataracts:

   • Contrast sensitivity testing
   • Corneal pachymetry (see CPB 0681 - Corneal Pachymetry)
   • Corneal topography (see CPB 0130 - Computerized Corneal Topography)
   • Electrophysiologic tests
   • External photography
   • Fluorescein angiography
   • Formal visual fields
   • Glare testing
   • Potential vision testing
   • Specialized color vision tests
   • Specular photographic microscopy
   • Ultrasound, contact B-scan, diagnostic*
   • Ultrasound, immersion B-scan, diagnostic*
   • Visual evoked potentials.
     

   The pre-operative tests listed above are considered experimental and investigational in most cases before cataract surgery.  There is inadequate evidence that other pre-operative tests are useful in determining the need for cataract surgery, nor predict the benefits or adverse outcomes from cataract surgery. 

   * B-scan ultrasound is considered medically necessary in place of A-scan ultrasound when the member has a dense cataract.

4. Aetna considers cataract removal surgery medically necessary according to the member’s level of visual impairment as follows:

   1. For members with visual disability with a Snellen Acuity of 20/50 or worse, cataract surgery is considered medically necessary when all of the following subjective, objective, and educational criteria are met:

      1. Subjective - The member perceives that his or her ability to carry out needed or desired activities is impaired.  The member's decision is based on (i) the member's own assessment of visual disability (e.g., impact on driving, viewing television, and special occupational or avocational needs) and, in particular, disability at near sight (e.g., reading, occupational activities requiring near vision); and (ii) the member's perception of the impact of the visual disability on lifestyle (e.g., loss of independence, loss of income).

         Note: In general, driving an automobile is the limiting life-style activity with visual acuity in the 20/50 to 20/60 range.  Almost all states require 20/40 vision in 1 eye to get a driver's license.  Household activities and reading are usually not limiting until the member reaches 20/70 vision.

      2. Objective - The best correctable Snellen visual acuity in the affected eye is 20/50 or worse, the eye examination confirms that the cataract is the limiting factor for improving visual function when other factors do not preclude improvement following surgery, and the member's medical and mental health permits surgery to be performed safely.

      3. Educational - The member has been educated about the risks and benefits of cataract surgery, including alternatives to treatment and the member determines if the expected reduction in the disability outweighs the potential risk, cost and inconvenience of surgery.

   2. For members with visual disability with a Snellen Acuity of 20/40 or better, cataract surgery is considered medically necessary when all of the following subjective, objective, and educational criteria are met:

      1. Subjective - The member perceives that his or her ability to carry out needed or desired activities is impaired.  The member's decision is based on: (i) the member's own assessment of visual disability (e.g., impact on driving, viewing television, and special occupational or avocational needs) and, in particular, disability at near sight (e.g., reading, occupational activities requiring near vision); (ii) the member's perception of the impact of the disability on lifestyle (e.g., loss of independence, loss of income); and (iii) the member's complaints of glare disabling eyesight in daylight conditions is inconsistent with the visual acuity measured in a darkened room; however, it must be confirmed by the documented assessment of visual functions under conditions of bright ambient light.  The loss of vision mimicking the member's complaints should be verified before the member is considered a candidate for cataract surgery.

         Note: A drop in visual acuity in bright light is the quantitative element that allows one to correlate the "loss of vision" with the "member's complaints".  The most common cataract that produces this type of light-related visual loss is a centrally located posterior subcapsular plaque (PSCP).

      2. Objective - The member's best correctable Snellen visual acuity is 20/40 Snellen or better in the affected eye, there is a significant loss of visual acuity in bright ambient light, the eye examination confirms that the cataract is the limiting factor for improving visual function when other factors do not preclude improvement following surgery, and the member's medical and mental health should permit surgery to be performed safely.

      3. Educational - The member has been educated about the risks and benefits of cataract surgery, including alternatives to treatment and the member determines if the expected reduction in the disability outweighs the potential risk, cost and inconvenience of surgery.

   3. One-eyed members: Cataract removal surgery is considered medically necessary for one-eyed members with visual disability of 20/80 or worse due to a cataract; that is, a member with irreversible, untreatable legal blindness (20/200 or worse) in the other eye.

   4. Cataract removal surgery involving removal of the lens is considered medically necessary without regard to visual disability when any of the following criteria is met:

      1. Member has lens-induced disease (e.g., phakomorphic glaucoma, phakolytic glaucoma, phakoanaphylactic endophthalmitis, dislocated or subluxated lens), or
      2. There is a need to visualize the fundus (retina) in an eye that has the potential for sight in any of the following conditions:
         
         
         • Diabetes with significant risk of reduced visual acuity (diabetic retinopathy) requiring photocoagulation management through clear media to monitor glaucoma;
         • To prepare for vitrectomy;
         • To prepare for surgical repair of retinal detachment; or
         • When other special investigations demonstrate intra-ocular pathology where further attention is important and requires clear media. 
           

   Note: Aetna considers standard fixed monofocal posterior chamber IOLs medically necessary for aphakia (e.g., Akreos posterior fixed monofocal IOL (Bausch & Lomb, Rochester, NY), Akreos AO Micro Incision Lens (Model MI60L), AcrySof SA60AT monofocal IOL (Alcon Surgical, Fort Worth, TX), AcrySof MA60AC, Alcon MZ30BD, and the Hydroview hydrogel foldable posterior IOL (Bausch & Lomb, Rochester, NY)).  Standard posterior chamber IOL for hyperopia (e.g., Clariflex, Sensar AR40e, Advanced Medical Optics, Santa Ana, CA) is considered medically necessary.  Aetna considers aspheric monofocal posterior chamber IOLs medically necessary for aphakia (e.g., AcrySof IQ IOL (Alcon Surgical, Fort Worth, TX), Tecnis (Z9000, Z9001, Z9002, ZA9003, Abbott Medical Optics, Santa Ana, CA), SofPort AO IOL (Bausch & Lomb, Rochester, NY), Sofport LI61AO, Akreos AO Aspheric IOL (Bausch & Lomb, Rochester, NY), Akreos SA 060, Hoya PY-60AD (Hoya Surgical Optics GmbH, Frankfurt, Germany), Tecnis AMO Aspheric IOL ZCB00 (Abbott Medical Optics, Santa Ana, CA), and Acrysof IQ SN60WS (Alcon Surgical, Fort Worth, TX)).  Standard fixed monofocal posterior chamber ultraviolet absorbing IOLs (e.g., AcrySof Natural blue-light filtering IOL (Alcon Surgical., Fort Worth, TX), AcrySof SN60WF, SofPort AO IOL with Violet Shield Technology (Bausch & Lomb, Rochester, NY), and C-flex IOL model 570C (Rayner Surgical Inc., Los Angeles, CA) are also considered medically necessary for aphakia.  (Note: Piggyback posterior chamber IOLs (i.e., placement of 2 IOLs in the same eye) are considered experimental and investigational).
   
   Aetna considers the following IOLs non-covered deluxe items: Accommodating posterior chamber IOLs (e.g., Crystalens (Eyeonics Inc., Aliso Viejo, CA); multi-focal posterior chamber IOLs (e.g., Array Model SA40 (Abbott Medical Optics, Santa Ana, CA),  ReZoom  (Abbott Medical Optics, Santa Ana, CA), Tecnis ZM900 and ZMAOO (Abbott Medical Optics, Santa Ana, CA), AcrySof ReSTOR, (Alcon Surgical, Fort Worth, TX), Acrysof Restor SA60D3 multifocal, Acrysof Natural ReSTOR SN60D3, AcrySof ReSTOR Aspheric IOL model SN6AD1, AcrySof ReSTOR Aspheric IOL model SN6AD3); and astigmatism-correcting (toric) posterior chamber IOLs (e.g., Staar Toric IOL (Star Surgical, Monrovia, CA), Staar Elastic Toric Lens Model AA4203TL, AcrySof Toric IOL (Alcon Surgical, Fort Worth, TX)) AcrySof Aspheric Toric IOL SN6AT3, SN6AT4 and SN6AT5, AcrySof Toric Models SA60T3, SA60T4 and SA60T5, AcrySof Toric Model SA60T, and Acrysof IQ Toric Model SN6ATT).

   Given that the intent of the multi-focal IOL, accommodating IOL and the toric IOL is to obviate the need for reading glasses post-surgery, these IOLs are considered not medically necessary.  For members who elect non-covered new technology IOLs, cataract removal and lens implantation would be considered medically necessary if the criteria for cataract surgery outlined above are met.  The new technology lens itself would be non-covered.

5. Aetna considers Nd:YAG laser capsulotomy medically necessary when performed 6 months or more following cataract extraction in members with visually significant clouding (opacification) of the posterior portion of the membrane that surrounds the lens (the posterior capsule).  Requests for Nd:YAG laser capsulotomy performed within 6 months of cataract extraction should be forwarded for medical review.

6. Aetna considers Nd:YAG laser capsulotomy experimental and investigational in any of the following situations because of insufficient evidence in the peer-reviewed literature: 

   1. If performed concurrently with cataract surgery; or
   2. If performed prophylactically; or
   3. If scheduled routinely after cataract surgery without regard to whether there is clinically significant opacification of the posterior capsule.
      

   Criteria for Inpatient Cataract Surgery:

   An inpatient setting for cataract removal surgery generally is not considered medically necessary.  However, inpatient surgery may be considered medically necessary for any of the following members:

   • Medical conditions are present that require prolonged post-operative observation by a nurse or skilled personnel and the member requires general medical and nursing care for a particularly complex ocular procedure(s); or
   • The member has multiple ocular conditions (e.g., best correctable vision in the non-operated eye is 20/200 or worse); or
   • The member will undergo multiple ocular procedures (e.g., extraordinary medical circumstances exist in which it may be dangerous or life-threatening for the member to undergo anesthesia twice, so dual cataract removal is performed); or

   • The member is mentally debilitated, diagnosed as mentally ill, or functionally incapacitated so that a risk of injury exists in the immediate post-operative period.  Physical disability prevents satisfactory immediate post-operative care.

This assessment of cataract surgery is supported by the Clinical Practice Guideline No. 4, Cataract in Adults: Management of Functional Impairment of the Cataract Management Guideline Panel of the Agency for Health Care Policy and Research (AHCPR, 1993).  The Panel, composed of an inter-disciplinary group of experts, reviewed the medical literature and prepared the guideline based on that review.  The guideline included findings concerning pre-operative testing, cataract removal surgery, and post-operative issues.

A cataract is a hardening and opacification (or clouding) of the normally transparent crystalline lens within the eye behind the pupil.  This condition usually occurs as a part of the aging process, developing on a continuum extending from minimal changes in the crystalline lens to the extreme stage of total opacification.  Rarely, a cataract may form within months when related to trauma, inflammation or use of some medications.  The intra-ocular lens (IOL) is a permanent plastic lens implanted inside the eye to replace the crystalline lens.  Dick (2005) stated that the potential clinical benefits of accommodative IOL technology for both cataract patients and refractive patients may place accommodative IOLs in a competitive position with multi-focal IOL technology.

Cataracts may result in progressive loss of vision.  The degree of loss depends on the location of the cataract, its size, and its density.

Cataracts may be nuclear or posterior subcapsular.  Nuclear cataracts are located in the central substance of the lens.  Posterior subcapsular cataracts are located beneath the posterior lens capsule, and affect vision out of proportion to the degree of cloudiness that is seen, because the cataract is located at the crossing point of the light rays from the viewed object.  These cataracts tend to cause glare in bright light.

Pre-operative Testing

Cataracts may be diagnosed with procedures included in the comprehensive ophthalmologic examination.  Cataracts may be seen on ophthalmoscopy as gray opacities in the lens.  Cataracts obscure the normal "red reflex" that is elicited by examining the dilated pupil with the ophthalmoscope held about 1 foot away.  Slit-lamp examination provides more details about the character, location, and extent of the opacity.

One specialized ophthalmologic service is frequently needed prior to cataract surgery in routine cases.  A-mode ultrasonography (A-scan) can be used to determine the appropriate pseudophakic power of the IOL.  For most cases involving a simple cataract, a diagnostic ultrasound A-scan is used.  This scan is billed and paid for separately from the comprehensive eye examination.  A B-scan is used in place of the A-scan when the patient has a dense cataract.  Alternatively, optical coherence biometry can be used in place of A- or B-scan ultrasonography to determine the appropriate pseudophakic power of the IOL.

Frequent changes in eyeglass prescription help maintain vision during cataract development.  When useful vision is lost, lens extraction is necessary.  Cataract extraction can be accomplished by removing the lens or by emulsification followed by irrigation and aspiration.  After cataract extraction, refractive correction is accomplished by glasses, contact lenses, or implantation of an IOL.  An A-scan ultrasound is not necessary unless an IOL is to be inserted.

The AHCPR Cataract Management Guideline Panel (the Panel, 1993) sought to determine what pre-operative tests are needed in most cases to determine the need for cataract surgery.  They examined whether these tests would indicate the presence or severity of a cataract, or predict the benefits or negative outcomes a patient may experience from the surgery.

The Panel found inadequate scientific evidence to support the use of most pre-operative tests in deciding whether cataract surgery is medically appropriate.  These pre-operative tests include contrast sensitivity testing, glare testing, potential vision testing, and specular photographic microscopy (endothelial cell photography).

Contrast sensitivity testing is a measure of the contrast level required for detection of a specified size of a test object.  This test reveals and quantifies decreased perception of low-contrast objects.  The Panel found inadequate evidence that contrast sensitivity testing provides information, beyond that obtained through a patient's history and eye examination that is useful for determining whether a patient would benefit from cataract surgery.

Glare testing measures the effect of simulated glare on vision function.  Disabling glare is often an indication that a cataract has developed.  The Panel found inadequate evidence that glare testing provides useful information beyond that obtained in a patient's history and eye examination.  This testing, however, may be useful for corroborating glare symptoms in a small percentage of cataract patients who complain of glare, yet measure good Snellen visual acuity.

Potential vision testing is designed to determine whether patients with obviously impaired vision have the potential to see well following cataract surgery.  The Panel found inadequate evidence that potential vision testing can help the ophthalmologist in predicting the outcome of cataract surgery.

Specular photographic microscopy may be done before an intra-ocular operation because the corneal endothelium is particularly sensitive to the trauma of the surgery.  This test is used to measure and record the evaluation of corneal endothelial cells.  Patients with a pre-operative reduction of their endothelial cell density are unusually sensitive to the trauma of surgery and may not maintain adequate visual functions following surgery.  The Panel also found inadequate evidence to support the use of specular photographic microscopy on all cataract patients in order to predict the response of the cornea to cataract surgery.  They found that many patients of low endothelial cell density can be identified through the patient's medical history and clinical examination.

The Panel also concluded that the following tests are not indicated as part of the pre-operative work-up for cataract surgery unless specific circumstances justify them:

• B-scan ultrasonography
• Corneal pachymetry
• Electrophysiologic tests
• External photography
• Fluorescein angiography
• Formal visual fields
• Specialized color vision tests
• Tonography.

The Panel found inadequate evidence that these tests can predict the benefits a patient may experience from cataract surgery or predict the negative outcomes of the surgery.  They concluded that there is inadequate evidence to support the use of these tests in most cases to determine the need for cataract removal surgery; they recognized, however, that these preoperative tests are needed in special circumstances.

The Panel stated that, for patients with a dense or cataract mature that interferes with ophthalmoscopic examination, a diagnostic B-mode ultrasonography (B-scan) may be appropriate to rule out retinal detachments or vitreous hemorrhages, ocular pathology which may influence the decision to perform cataract surgery.

Corneal topography is not routinely indicated prior to cataract removal surgery; it may be useful when irregular astigmatism is suspected of contributing to visual impairment (AAO, 2001).

Cataract Removal Surgery

Cataract removal surgery is an established surgical procedure with excellent outcomes in improving vision and removing visual impediments.  Cataract surgery is usually performed under local anesthesia.

The Panel stated that cataract removal surgery should be performed on each eye separately and sufficient time be allowed for the first eye to heal before the second cataract removal is performed (an interval of 2 to 6 months is customary).

YAG Laser Capsulotomy

Posterior capsule opacification is a common complication after cataract surgery.  It can develop months or years later and is due to a slow growth of epithelial cells remaining from the removed cataract.

The Panel found that posterior capsular opacification rarely occurs within the first 3 months of surgery, and that it is uncommon for posterior capsular opacification to occur within the first 6 months of surgery.  The Panel concluded that posterior capsulotomy should never 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 predict the time at which opacification will occur.  The Panel also concluded that Nd:YAG laser capsulotomy should not be performed prophylactically or scheduled routinely at particular times after cataract surgery.  For similar reasons, manual removal of the posterior capsule, performed with a needle or hook (called corneoscleral section), should not be performed at the time of cataract surgery.

New Technology Intra-ocular Lenses

Surgical treatment of cataract involves replacing the patient's opacified lens with an artifical lens, which is usually of fixed power (monofocal), requiring the use of reading glasses for near vision.  More recently, IOLs have been developed that are designed to allow both distance and reading vision without glasses.  These can be either multi-focal lenses, which enable both near and distance vision by virtue of the design of the lens itself, or accommodating lenses, which are intended to move within the eye in a manner similar to a natural human lens.

In a prospective, randomized controlled study, Marshall and associates (2005) verified the safety and effectiveness of the new AcrySof Natural blue-light filtering IOL, which was designed to achieve a light-transmission spectrum similar to that of the natural human crystalline lens.  A total of 150 patients received the AcrySof Natural IOL and 147 patients received the AcrySof single-piece IOL as a control.  Patients with bilateral age-related cataracts who were willing and able to wait at least 30 days between cataract procedures and had verified normal pre-operative color vision were eligible for the study.  Standardized surgery included a 4.0 to 5.0 mm capsulorhexis and phacoemulsification.  All lenses were inserted in the capsular bag, with verification of in-the-bag placement of both haptics.  In all bilateral implantation cases, the same model IOL was used in each eye.  Post-operatively, contrast sensitivity and color perception were measured up to 180 days and up to 1 year (for visual acuity) after implantation.  No statistically significant differences were observed between the 2 groups in visual acuity, contrast sensitivity evaluated under mesopic and photopic conditions, or the number of subjects who passed the Farnsworth D-15 color perception test.  There were no lens-related adverse events in either group.  These investigators concluded that the blue-light filtering AcrySof Natural IOL was equivalent to the conventional AcrySof lens in terms of post-operative visual performance.  They stated that additional long-term clinical studies should show whether the IOL actually provides the theoretical benefits to retinal health.

In a prospective, randomized controlled trial, Heatley and colleagues (2005) examined the near visual clinical performance of an accommodative IOL when compared with a standard monofocal IOL in a fellow eye comparison.  A total of 30 patients (60 eyes) with bilateral cataracts but otherwise normal eyes were recruited from a single university hospital cataract waiting list.  Patients were randomized to receive either the 1CU accommodative IOL in their first eye or the Acrysof MA30 monofocal IOL.  The alternative lens was then implanted in the second eye 4 to 6 weeks later.  At all follow-up visits, a full assessment was made of distance, near and reading visual performance, and accommodative amplitude.  Data were available for all patients at 6 months and 20 patients at 1 year.  At 6 months, no difference was found in distance-corrected visual acuity between the 2 IOLs.  Of the 1CU eyes, 9 patients (30 %) could read J6 or better at a reading speed of 80 words/min or better.  In these 9 patients, the mean difference in the amplitude of accommodation between the 2 eyes was 0.71 diopters.  These researchers concluded that no measurable variable distinguished eyes that developed functional reading vision from those that did not.  The accommodative IOL appears to produce improved near vision in some eyes, but it does not work in all eyes, and in eyes where there is apparent accommodation, there is a discrepancy between subjective reading performance and the modest measured increase of accommodative amplitude.

Macsai et al (2006) evaluated and compared the visual outcomes and accommodative amplitude in cataract patients after implantation of the Crystalens versus standard monofocal IOLs.  The authors concluded that additional studies are needed to assess the visual outcomes of the Crystalens in a larger number of patients.  They also noted that "[g]iven our study limitations, we found successful distance and near vision results with the implantation of Crystalens IOL.  Further studies to evaluate long-term results of the accommodative capacity of the Crystalens IOL and to help sort out the effects of pseudoaccommodation are warranted".

The Canadian Agency for Drugs and Technologies in Health (CADTH)'s evaluation of a ccomodative IOLs for age-related cataracts (Scott, 2006) stated that limited evidence suggests that accomodative IOLs provide better near vision than mono-focal IOLs, but not better than multi-focal IOLs.  In addition, the CADTH assessment stated that long-term follow-up is needed to confirm patient outcomes, and ascertain if the benefits justify the additional cost.

A meta-analysis by Takakura et al (2010) found no clear evidence of near visual acuity improvement with accommodating IOLs compared to monofocal IOLs.  The investigators conducted a meta-analysis to compare accommodating IOLs and monofocal IOLs in restoring accommodation in cataract surgery.  Because of measurement-scale variations, outcomes were pooled for distance-corrected near visual acuity (DCNVA) as standardized mean differences with 95 % confidence intervals [CIs] and anterior displacement of the lens as weighted mean differences (95 % CI).  The metaanalysis comprised 12 randomized controlled studies of 727 eyes.  The authors reported that, based on 10 studies that compared DCNVA, accommodating IOLs were favored but failed the test of heterogeneity (I(2) = 94 %).  However, pooling only the 6 homogeneous trials (I(2) = 43 %) showed no difference (standardized mean difference, -0.16; 95 % CI: -0.56 to 0.25).  The authors stated that heterogeneity could not be explained by any characteristic of the study population or methodology.  Based on 4 studies that evaluated pilocarpine-induced IOL shift, there was a significant anterior compared with the control (weighted mean difference, 95 % CI: -0.36 - 0.47 to -0.24), although the studies were heterogeneous (I(2) = 58 %).  Three of 5 studies mentioning posterior capsule opacification reported increased rates in the accommodating IOL group postoperatively.  The authors concluded that there was no clear evidence of near acuity improvement despite statistically significant pilocarpine-induced anterior lens displacement.  The authors stated that further randomized controlled studies with standardized methods evaluating adverse effects (e.g., posterior capsular opacification) are needed to clarify the trade-offs.

Guidance on accommodating intraocular lenses from the National Institute for Health and Clinical Excellence (NICE, 2007) concluded: "Current evidence suggests that there are no major safety concerns associated with the implantation of accommodating lenses for cataract.  There is evidence of short-term efficacy in correcting visual acuity but there is inadequate evidence that the procedure achieves accommodation.  Therefore, the procedure should not be used without special arrangements for consent and for audit or research."  The assessment stated that publication of long-term efficacy outcomes of the procedure will be useful, particularly on the effects on accommodation.

Guidance on multi-focal IOLs from the National Institute for Health and Clinical Excellence (NICE, 2008) concluded: "The evidence on the implantation of multifocal (non-accommodative) intraocular lenses (IOLs) during cataract surgery raises no major safety concerns.  Current evidence on the procedure’s efficacy shows that it can provide good near and distance vision without the need for spectacles, but this is at the risk of a variety of potential visual disturbances."

In a prospective, randomized, controlled clinical trial, Martínez Palmer et al (2008) evaluated visual function of 3 types of multi-focal IOLs and 1 monofocal IOL (as the control group) after cataract surgery.  A total of 114 patients were included in the study.  Subjects received monofocal Tecnis Z9000 (AMO) (n = 24, 48 eyes); symmetric diffractive multi-focal Tecnis ZM900 (AMO) (n = 26, 52 eyes); zonal refractive multi-focal ReZoom (AMO) (n = 32, 64 eyes); or asymmetric diffractive multi-focal TwinSet (Acri.Tec) (n = 32, 64 eyes) IOLs.  Mean binocular distance best spectacle-corrected visual acuity (BSCVA) (logMAR) was 0.05 for controls, 0.08 for ZM900, 0.07 for ReZoom, and 0.11 for TwinSet, with mean binocular distance BSCVA at near of 0.49, 0.06, 0.22, and 0.11, respectively.  Mean contrast sensitivity was better for the monofocal IOL group than for the multi-focal IOLs.  Patients assigned to TwinSet had less favorable contrast sensitivity scores.  Patients with monofocal IOLs had more frequently recommended near addition (74 %) than those with multi-focal IOLs.  Patients with refractive ReZoom had also recommended near addition more frequently than the 2 diffractive groups.  The percentage of dysphotopsia phenomena was 81 % in patients with diffractive multifocal ZM900 compared with 48 % in patients with monofocal IOLs, 53 % with refractive ReZoom, and 47 % with diffractive TwinSet.  The authors concluded that the monofocal IOL showed better visual function and lesser photic phenomena than multi-focal IOLs; however patients were spectacle-dependent.  ReZoom provided better distance BSCVA than the TwinSet diffractive model.  Patients with Tecnis and TwinSet diffractive multi-focal IOLs were more spectacle-independent than patients with ReZoom.  Patients with TwinSet had the worst visual function.  Patients implanted with the Tecnis diffractive ZM900 were those reporting more photic phenomena.