Behavioral Vision Therapy and Vision Restoration Therapy
Number: 0321
Table Of Contents
PolicyApplicable CPT / HCPCS / ICD-10 Codes
Background
References
Policy
Scope of Policy
This Clinical Policy Bulletin addresses behavioral vision therapy and vision restoration therapy.
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Experimental, Investigational, or Unproven
- Aetna considers behavioral vision therapy, also known as visual perceptual training, experimental, investigational, or unproven for the treatment of visual perceptual dysfunctions and for all other indications (e.g., body dysmorphic disorder, and reading and/or spelling disorders) because its effectiveness has not been validated in well-designed prospective clinical studies.
- Aetna considers vision restoration therapy experimental, investigational, or unproven for the treatment of visual field deficits due to ischemic optic neuropathy, neurotrauma, or stroke, and for all other indications because its effectiveness has not been validated in well-designed prospective clinical studies.
- Aetna considers vision restoration therapy, alone or in combination with transcranial direct current stimulation, experimental, investigational, or unproven for the treatment of visual field deficits following stroke or neurotrauma because its clinical value has not been established.
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Policy Limitations and Exclusions
Note: Behavioral vision therapy / visual perceptual training and vision restoration therapy should be distinguished from orthoptic vision therapy. See CPB 0489 - Orthoptic Vision Therapy.
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Related Policies
Background
Behavioral Vision Therapy / Visual Perceptual Training
Behavioral vision therapy is a modern term for visual perceptual training. The American Association for Pediatric Ophthalmology & Strabismus (AAPOS) state that behavioral/perceptual vision therapy is a category of vision therapy in which eye exercises are incorporated in order to improve visual processing and visual perception. According to the AAPOS, behavioral vision therapy is considered to be scientifically unproven (AAPOS, 2020).
Behavioral vision therapy / visual perceptual training, generally performed by behavioral optometrists, occupational therapists trained in evaluation and treatment of problems with visual skills, and behavioral health professionals (e.g., psychologists, psychotherapists), is a psycho-educational intervention that focuses on perceptual dysfunctions that are claimed to contribute to delay in speech and language development, particularly in preschool children.
The Handbook of Visual Perceptual Training (Cunningham and Reagan, 1972) (the Handbook) defines visual perception as "that process by which impressions observed through the medium of the eye are transmitted to the brain where relationship to past experiences takes place." According to the Handbook, "it is concluded that visual perceptual deficits fall into patterns of a syndrome and that each component may impinge upon any number of other factors or may function independently. Visual perceptual dysfunction does not include lack of visual perceptual stimulation; it does involve improper choice of ontogenetic sequencing for such stimulation. It is not a matter of either-or; rather it is a matter of degree. It represents an inefficient developmental functioning that is a handicap to cognitive process. It is related to both cognition and emotional development" (Cunningham and Reagan, 1972). The authors of the Handbook further note that "concomitant factors of visual perceptual dysfunction may be short attention span, hyperactivity, distractibility, social adjustment difficulties, delayed motor perceptual ability, depressed academic achievement, inadequate body image and low frustration level." "Visual perception dysfunction," according to the Handbook, "is to be classified as a learning disability and language disorder."
Visual perception training programs involve an "integrated program involving speech and language activities, a wide range of sensory modalities and visual-motor perceptual activities" (Cunningham and Reagan, 1972). These activities include motor rhythm activities, body image training, as well as training in spatial and directional relationships. "Suggested activities are grouped under five main headings: coordination of eye-motor movements, distinguishing foreground from background, visual memory, spatial position and relationship to space ... Included in the activities are speech, language and visual-motor perceptual tasks that involve use of all senses."
Although some exercises are similar, behavioral vision therapy / visual perceptual training should be distinguished from orthoptic vision therapy. Behavioral vision therapy / visual perceptual training is directed toward perceptual dysfunctions that allegedly affect language and learning abilities, whereas orthoptic vision therapy is a set of exercises directed toward specific deficiencies in the movements and/or focusing of the eye (e.g., convergence insufficiency, disorders of accommodation, esophoria, strabismus, etc.). Patients receive orthoptic vision therapy to treat visual disturbances that may theoretically cause developmental delays and learning disabilities, whereas patients may receive behavioral vision therapy / vision perception training to remedy developmental delays and learning disabilities without having any identified dysfunction of eye movements or focusing.
According to the American Academy of Pediatrics (AAP), the American Academy of Pediatric Ophthalmology and Strabismus (AAPOS), and the American Academy of Ophthalmology (AAO) Joint Statement: Learning Disabilities, Dyslexia, and Vision - Reaffirmed 2014, research has shown that most reading disabilities are not caused by altered visual function. These professional societies jointly concluded that "there is inadequate scientific evidence to support the view that subtle eye or visual problems, including abnormal focusing, jerky eye movements, misaligned or crossed eyes, binocular dysfunction, visual-motor dysfunction, visual perceptual difficulties, or hypothetical difficulties with laterality or "trouble crossing the midline" of the visual field, cause learning disabilities". Furthermore, evidence does not support the effectiveness of tinted lenses and tinted filters to treat visual perceptual dysfunctions "because of the weaknesses in methodology and statistics, variability in techniques in the trials, and the largely negative results".
Vision Restoration Therapy (VRT)
Vision restoration therapy (VRT) targets the vision center of the brain and is intended to improve visual function in patients with visual field deficits that may result from brain injury or stroke. Patients utilize a computer screen to focus on a displayed central point and respond every time they see light stimuli appear. The light stimuli are presented in the area most likely to recover visual function, an area that will change as therapy progresses and vision is improved. While there are studies evaluating the usefulness of VRT, there is inadequate evidence of effectiveness for this treatment.
Meuller et al (2003) performed a retrospective analysis of 69 patients with visual field deficits following neurotrauma or stroke after they had performed a 6 month regimen of VRT. Specifically, these researchers wanted to ascertain
- if VRT affects activities of daily life (ADL) measures, and
- to what extent any subjective changes correlate with quantitative measures of visual field enlargements.
A retrospective analysis was performed with data of 69 patients who had been interviewed after 6 months of VRT. Patient testimonials were analyzed post-hoc and correlated with demographic status as well as pre- and post-RT changes as measured by perimetric testing. As previously described, VRT significantly increased detection ability and most patients (88 %) reported subjective benefits in ADL. A correlation analysis of quantitative parameters of visual field enlargements with subjective patient testimonials was performed. Significant correlation was found in the categories "carrying out hobbies" (r = 0.360) and for "general improvement of vision" (r = 0.244). A trend was evident for the category "reading" (r = 0.215). No correlation was found between visual field size improvements and "visual confidence/mobility" and "ability to avoid collisions". Thus, visual field size appears only to be one, surprisingly minor, factor among others (such as temporal processing) determining subjective vision in brain damaged patients.
Glisson (2006) noted that VRT has shown promise as a treatment strategy to improve visual field deficits in patients with lesions of the brain or optic nerve. However, objective measures of its effectiveness have remained controversial. The author reviewed the current theories supporting the reported benefits of VRT, and the dissenting opinions, reconsidered VRT as an emerging therapy. The benefits of VRT have been challenged by a study suggesting that no improvement exists with careful control of fixation. Alternatively, others suggested that eye movements are not induced by VRT. Functional imaging studies demonstrated the potential role of plasticity in VRT. While the exact mechanism remains to be elucidated, subjective improvement in daily functioning was reported in a significant percentage of patients. The author concluded that VRT is a non-invasive, home-based strategy for the rehabilitation of patients with visual field loss caused by structural or ischemic damage. While subjective benefits in functional status have been reported by patients following completion of the program, debate centered around the inadequacy of the methods used to document its effectiveness. Until such a method is validated by carefully controlled studies, subjective improvement in visual function stands alone as evidence of VRT's benefit.
Mueller and colleagues (2007) evaluated the outcome of VRT in a large sample of clinical patients and studied factors contributing to subjective and objective measures of visual field alterations. Clinical observational analysis of visual fields of 302 patients before and after being treated with computer-based VRT for a period of 6 months at 8 clinical centers in central Europe were carried out. The visual field defects were due to ischemia, hemorrhage, head trauma, tumor removal or anterior ischemic optic neuropathy (AION). Primary outcome measure was a visual field assessment with super-threshold perimetry. Additionally, conventional near-threshold perimetry, eye movements and subjective reports of daily life activities were assessed in a subset of the patients. Vision restoration therapy improved patients' ability to detect super-threshold stimuli in the previously deficient area of the visual field by 17.2 % and these detection gains were not significantly correlated with eye movements. Notable improvements were seen in 70.9 % of the patients. Efficacy was independent of lesion age and etiology, but patients with larger areas of residual vision at baseline and patients over 65 years old benefited most. Conventional perimetry validated visual field enlargements and patient testimonials confirmed the improvement in every day visual functions. The authors concluded that VRT improves visual functions in a large clinical sample of patients with visual field defects involving the CNS, confirming former experimental studies.
To recapitulate, while there are studies assessing the clinical value of the VRT, there is insufficient evidence of effectiveness for this treatment. Drawbacks of published studies are small sample sizes and short follow-up time.
NovaVision VRT
NovaVision offers vision restoration therapy (VRT), a home-based program, which is purported to target the vision center of the brain and improve visual function in patients with visual field deficits that may have resulted from stroke or TBI. Patient employs a computer screen to focus on a displayed central point and responds every time they see light stimuli appear. The light stimuli are presented in the area most likely to recover visual function, an area that will change as treatment progresses and vision is improved.
McFadzean (2006) reviewed the controversial findings for NovaVision's VRT. It has been claimed that NovaVision's computerized therapy results in expansion of the visual field in optic nerve and occipital lesions, but the outcome has been challenged on the grounds of unsatisfactory perimetric control of central fixation and disputed mechanisms. The author noted that in clinical practice NovaVision's VRT should not currently gain acceptance in view of unacceptable perimetric standards and equivocal results. Possible effects on a relative scotoma at the edge of a lesion have not been adequately explored. In the interim, research should also be focused on compensatory eye movement strategies.
Ambylopia in Adults
Astle et al (2011) noted that amblyopia presents early in childhood and affects approximately 3 % of western populations. The monocular visual acuity loss is conventionally treated during the "critical periods" of visual development by occluding or penalizing the fellow eye to encourage use of the amblyopic eye. Despite the measurable success of this approach in many children, substantial numbers of people still suffer with amblyopia later in life because either they were never diagnosed in childhood, did not respond to the original treatment, the amblyopia was only partially remediated, or their acuity loss returned after cessation of treatment. In this review, these researchers examined if the visual deficits of this largely over-looked amblyopic group are amenable to conventional and innovative therapeutic interventions later in life, well beyond the age at which treatment is thought to be effective. There is a considerable body of evidence that residual plasticity is present in the adult visual brain and this can be harnessed to improve function in adults with amblyopia. Perceptual training protocols have been developed to optimize visual gains in this clinical population. Results thus far are extremely encouraging; marked visual improvements have been demonstrated, the perceptual benefits transfer to new visual tasks and appear to be relatively enduring. The essential ingredients of perceptual training protocols are being incorporated into video game formats, facilitating home-based interventions. The authors concluded that many studies support perceptual training as a tool for improving vision in amblyopes beyond the critical period. They stated that should this novel form of treatment stand up to the scrutiny of a randomized controlled trial, clinicians may need to re-evaluate their therapeutic approach to adults with amblyopia.
Anterior Ischemic Optic Neuropathy
In a pilot study, Jung et al (2008) evaluated the effects of VRT on the visual function of 10 patients with stable anterior ischemic optic neuropathy (AION). All patients were evaluated before VRT and after 3 and 6 months of treatment by Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity, contrast sensitivity, reading speed, 24-2 SITA-standard Humphrey visual field (HVF), high-resolution perimetry (HRP) (perimetry obtained during VRT), and vision-based quality of life questionnaire. Patients were randomized between 2 VRT strategies (5 in each group):
- VRT in which stimulation was performed in the seeing VF of the affected eye ("seeing field-VRT"); and
- VRT in which stimulation was performed along the area of central fixation and in the ARV (areas of residual vision) of the affected eye ("ARV-VRT").
The results of the HRP, HVF, and clinical assessment of visual function were compared for each patient and between the 2 groups at each evaluation. Visual acuity qualitatively improved in the ARV-VRT group, however the change was not statistically significant (p = 0.28). Binocular reading speed significantly improved in the ARV-VRT group (p = 0.03). HVF foveal sensitivity increased mildly in both groups (p = 0.059); HRP analysis showed a similar increase in stimulus accuracy in both groups (mean improvement of about 15 %). All patients reported functional improvement after VRT. The authors concluded that despite a small sample, the study showed a trend toward improvement of visual function in the ARV-VRT group. Improvement of HRP in both groups may reflect diffusely increased visual attention (neuronal activation), or improvement of an underlying sub-clinical abnormality in the "seeing" visual field of patients with optic neuropathies. The author noted that a small sample size limited the conclusions that can be reached from this study.
Body Dysmorphic Disorder
Beilharz and colleagues (2017) noted that recent advances in body dysmorphic disorder (BDD) have explored abnormal visual processing, yet it is unclear how this relates to treatment. These researchers summarized the current understanding of visual processing in BDD and reviewed associated treatments. The literature was collected through PsycInfo and PubMed. Visual processing articles were included if written in English after 1970, had a specific BDD group compared to healthy controls and were not case studies. Due to the lack of research regarding treatments associated with visual processing, case studies were included. A number of visual processing abnormalities are present in BDD, including face recognition, emotion identification, aesthetics, object recognition and gestalt processing. Differences to healthy controls include a dominance of detailed local processing over global processing and associated changes in brain activation in visual regions. Perceptual mirror retraining and some forms of self-exposure have demonstrated improved treatment outcomes, but have not been examined in isolation from broader treatments. The authors concluded that despite these abnormalities in perception, particularly concerning face and emotion recognition, few BDD treatments attempt to specifically remediate this. The development of a novel visual training program that addresses these widespread abnormalities may provide an effective treatment modality.
Hemianopia and Homonymous Hemianopia
Hemianopia (or hemianopsia) is a clinical term used to describe a visual field loss of one half of a vertical visual field, which results from the disruption of visual pathways within the central nervous system and can affect one or both eyes (Ruddy and Cardenas, 2021). Homonymous hemianopia (or hemianopsia) is a field loss deficit in the same halves of the visual field of each eye, which can result from cerebrovascular injury or tumor (Wolberg and Kapoor, 2021).
In a retrospective study, Romano and colleagues (2008) examined the effect of a visual rehabilitation intervention on visual field defects in a U.S. cohort. Vision restoration therapy consists of a specific pattern of stimulation that is directed at the border of the blind field. This study evaluated individuals with homonymous visual field defect from retrochiasmatic lesions treated with 6 modules of VRT. Supra-threshold visual field testing of the central 43 x 32 was obtained at baseline and after each module. The main outcome measures were the change in stimuli detection and the shift in the position of the border of the blind field. The impact of age, time from injury and type of visual field defect were analyzed. Among 161 patients, the mean absolute improvement in stimuli detection was 12.8 %. The average border shift was 4.87. Improvements of greater than or equal to 3 % was noted in 76 % of patients. Absolute change in stimulus detection of greater than or equal to % at mid-therapy was associated with a greater final improvement. Age, time from lesion and type of visual field defect did not influence the degree of field expansion. The authors concluded that VRT improves stimulus detection and results in a shift of the position of the border of the blind field as measured on suprathreshold visual field testing. These results support prior reports and support VRT as a useful rehabilitative intervention for a proportion of patients with visual field defects from retrochiasmatic lesions. However, the findings of this study were limited by lack of randomization, control group and long-term follow-up.
In a comparative case study, Plow et al (2011) attempted to standardize a protocol for promoting visual rehabilitative outcomes in post-stroke hemianopia by combining occipital cortical transcranial direct current stimulation (tDCS) with VRT. Two patients, both with right hemianopia after occipital stroke damage were included in this study. Both patients underwent an identical VRT protocol that lasted 3 months (30 mins, twice-daily, 3 days/week). In patient 1, anodal tDCS was delivered to the occipital cortex during VRT training, whereas in patient 2 sham tDCS with VRT was performed. The primary outcome, visual field border, was defined objectively by using high-resolution perimetry. Secondary outcomes included subjective characterization of visual deficit and functional surveys that assessed performance on activities of daily living. For patient 1, the neural correlates of visual recovery were also investigated, by using functional magnetic resonance imaging. Delivery of combined tDCS with VRT was feasible and safe. High-resolution perimetry revealed a greater shift in visual field border for patient 1 versus patient 2. Patient 1 also showed greater recovery of function in activities of daily living. Contrary to the expectation, patient 2 perceived greater subjective improvement in visual field despite objective high-resolution perimetry results that indicated otherwise. In patient 1, visual function recovery was associated with functional magnetic resonance imaging activity in surviving peri-lesional and bilateral higher-order visual areas. The authors concluded that these findings of preliminary case comparisons suggested that occipital cortical tDCS may enhance recovery of visual function associated with concurrent VRT through visual cortical re-organization. They stated that future studies may benefit from incorporating protocol refinements such as those described here, which include global capture of function, control for potential confounds, and investigation of underlying neural substrates of recovery.
In a review on "Homonymous hemianopia and vision restoration therapy", Frolov and colleagues (2017) noted that homonymous hemianopia from stroke causes visual disability. Although some patients experience spontaneous improvement, others have limited to no change and may be left with a severe disability. Current rehabilitation strategies are compensatory and cannot restore function. Animal studies suggested that central nervous system plasticity could allow for re-direction of lost visual function into undamaged areas of cortex. A commercial therapy system was developed, from which claims of visual field expansion were disputed by independent researchers. The authors concluded that the treatment remains controversial with seemingly contradictory data being generated; continued research is underway to demonstrate the (non-)efficacy of this treatment method.
Optic Neuritis
Schinzel et al (2012) noted that there is a pilot study that examined if residual visual deficits after past or recent optic neuritis can be reduced by means of VRT. They stated that if VRT is shown to improve visual function after optic neuritis, this method might be a first therapeutic option for patients with incomplete recovery from optic neuritis.
Reading and/or Spelling Disorders
Galuschka and associates (2016) noted that 3 to 11 % of children and adolescents suffer from a reading and/or spelling disorder. Their poor written-language skills markedly impair their scholastic performance and are often associated with other mental disorders. A great deal of uncertainty still surrounds the question of the appropriate methods of diagnosis and treatment. These investigators systematically searched for pertinent publications in databases and literature reference lists, summarized the evidence in 6 tables, and examined some of it in a meta-analysis. Recommendations were developed in a consensus conference. A reading and/or spelling disorder should only be diagnosed if performance in these areas is below average. It should be examined if an attention deficit-hyperactivity disorder (ADHD), anxiety disorder, or disorder of arithmetical skills is also present. Reading and spelling performance should be reinforced with systematic instruction about letter-sound and sound-letter correspondences, letter-syllable-morpheme synthesis, and sound-syllablemorpheme analysis (g' = 0.32) (recommendation grade A). Spelling ability responds best to spelling-rule training (recommendation grade A). Irlen lenses, visual and/or auditory perceptual training, hemispheric stimulation, piracetam, and prism spectacles should not be used (recommendation grade A). The authors concluded that evidence- and consensus-based guidelines for the diagnosis and treatment of reading and/or spelling disorders in children and adolescents are now available for the first time. Reading and spelling abilities should be systematically and comprehensively reinforced, and potential co-morbid disorders should be sought and treated appropriately. They stated that the effectiveness of many treatments now in use has not been documented; if they are to be used in the future, they must be tested in randomized, controlled trials (RCTs). For adult sufferers, adequate diagnostic instruments and therapeutic methods are not yet available.
References
The above policy is based on the following references:
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- American Academy of Pediatrics. Learning disabilities, dyslexia, and vision: A subject review. Committee on Children with Disabilities, American Academy of Pediatrics (AAP) and American Academy of Ophthalmology (AAO), American Association for Pediatric Ophthalmology and Strabismus (AAPOS). Pediatrics. 1998;102(5):1217-1219.
- American Academy of Ophthalmology (AAO), American Academy of Pediatrics (AAP), American Association for Pediatric Ophthalmology and Strabismus, and American Association of Certified Orthoptists. Joint statement: Learning disabilities, dyslexia, and vision - reaffirmed 2014. San Francisco, CA: AAO; 2009 (reaffirmed 2014). Available at: https://www.aao.org/clinical-statement/joint-statement-learning-disabilities-dyslexia-vis. Accessed March 11, 2022.
- American Association for Pediatric Ophthalmology and Strabismus (AAPOS). Vision therapy. AAPOS [website]. Roseville, MN; AAPOS; updated December 2020.
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- Beilharz F, Castle DJ, Grace S, Rossell SL. A systematic review of visual processing and associated treatments in body dysmorphic disorder. Acta Psychiatr Scand. 2017;136(1):16-36.
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