Vision Therapy and Orthoptics

Vision Therapy: A Primer and Caution for Pediatricians

Vision therapy, also known as behavioral therapy, is theorized by its practitioners to treat a variety of visual disorders, including learning disability in children. However, the utility of vision therapy to treat various learning disabilities is challenged by the American Academy of Pediatrics, American Academy of Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus, and the American Association of Certified Orthoptists. The purpose of this review is to (1) provide an overview of vision therapy, (2) evaluate the evidence for vision therapy, and (3) give practical recommendations for pediatric primary care providers regarding vision therapy. A review of the literature demonstrates evidence that vision therapy is useful in the management of convergence insufficiency only. There is insufficient evidence to recommend in-office vision therapy for the management of other types of strabismus, amblyopia, or learning disability in the pediatric population.

A dichoptic feedback-based oculomotor training method to manipulate interocular alignment

Strabismus is a prevalent impairment of binocular alignment that is associated with a spectrum of perceptual deficits and social disadvantages. Current treatments for strabismus involve ocular alignment through surgical or optical methods and may include vision therapy exercises. In the present study, we explore the potential of real-time dichoptic visual feedback that may be used to quantify and manipulate interocular alignment. A gaze-contingent ring was presented independently to each eye of 11 normally-sighted observers as they fixated a target dot presented only to their dominant eye. Their task was to center the rings within 2° of the target for at least 1 s, with feedback provided by the sizes of the rings. By offsetting the ring in the non-dominant eye temporally or nasally, this task required convergence or divergence, respectively, of the non-dominant eye. Eight of 11 observers attained 5° asymmetric convergence and 3 of 11 attained 3° asymmetric divergence. The results suggest that real-time gaze-contingent feedback may be used to quantify and transiently simulate strabismus and holds promise as a method to augment existing therapies for oculomotor alignment disorders.

Vision therapy: are you kidding me? Problems with current studies

BACKGROUND AND PURPOSE

Orthoptic exercises are routinely prescribed to treat symptoms of convergence insufficiency (CI). The type and duration of treatment tends to vary among providers as until recently, few strong randomized control studies have addressed the efficacy of convergence insufficiency management. The aim of this paper is to address these studies and discuss their limitations.

METHODS

A review of the literature pertaining to convergence insufficiency was conducted. Articles relevant to the treatment of this disorder were analyzed, and those with adequate studies pertaining to CI treatment methods were included.

RESULTS

There are limited randomized control trials evaluating the effectiveness of vision therapy, and those that do exist have limitations: small patient populations, differing outcome measures, treatment length and intensity, and placebo effects, which are all confounding factors when assessing the validity of the current studies.

CONCLUSION

Despite the prevalence of convergence insufficiency, the known efficacy of vision therapy remains somewhat questionable. There is evidence to suggest that some form of therapy is effective in reducing symptoms and clinical findings of convergence insufficiency, but there is a lack of equal comparison in order to conclude which forms of treatment are best.

The effect of visual therapy on the ocular motor control of seven- to eight-year-old children with developmental coordination disorder (DCD)

The aims of this study were to determine the extent of ocular, motor control problems and the effect of visual therapy on such problems, among seven- to eight-year-old children diagnosed with DCD. Thirty-two, children with a mean age of 95.66 months (SD ± 3.54) participated in the study. The MABC was used to classify children into DCD categories (<15th, percentile) while the Sensory Input Systems Screening Test and QNST-II, were used to evaluate ocular motor control. A two-group pre-test-post-test, cross-over design was followed with a retention test two years, thereafter to determine the lasting effect of the visual therapy, intervention. The 18-week visual therapy programme was executed once a week, for 40 min during school hours, after which the two groups were, crossed over. Percentages of ocular motor control problems ranging, between 6.25% and 93.75% were found in both the groups before participating, in the visual therapy programme, with the highest percentage problems found, in visual pursuit with the left eye. Visual therapy contributed to a, significant improvement of 75-100% in visual pursuit, fixation, ocular, alignment and convergence, with significant lasting effects (p<0.001). Visual therapy is recommended for children with DCD experiencing poor, ocular motor control.

Developmental dyslexia and vision

Developmental dyslexia affects almost 10% of school-aged children and represents a significant public health problem. Its etiology is unknown. The consistent presence of phonological difficulties combined with an inability to manipulate language sounds and the grapheme-phoneme conversion is widely acknowledged. Numerous scientific studies have also documented the presence of eye movement anomalies and deficits of perception of low contrast, low spatial frequency, and high frequency temporal visual information in dyslexics. Anomalies of visual attention with short visual attention spans have also been demonstrated in a large number of cases. Spatial orientation is also affected in dyslexics who manifest a preference for spatial attention to the right. This asymmetry may be so pronounced that it leads to a veritable neglect of space on the left side. The evaluation of treatments proposed to dyslexics whether speech or oriented towards the visual anomalies remains fragmentary. The advent of new explanatory theories, notably cerebellar, magnocellular, or proprioceptive, is an incentive for ophthalmologists to enter the world of multimodal cognition given the importance of the eye's visual input.