[Rehabilitation methods for individuals with functional vision disorders]. / Metody reabilitatsii lits s funktsional'nymi rasstroistvami zreniia.

PURPOSE: To develop a rehabilitation system for people with functional vision disorders. MATERIAL AND METHODS: The study included 56 schoolchildren with functional visual impairments aged 8-17 years, among which 7 had spasm of accommodation, and 49 - paralysis or paresis of accommodation. The examination included visometry, refractometry, ophthalmometry, measurement of the axial eye length, absolute and relative accommodation parameters, fusional reserves, as well as character of binocular vision and asthenopic complaints. RESULTS: The patients with spasms, pareses and paralyses of accommodation were revealed to have decreased visual acuity, absence or sharp decrease in absolute and relative accommodation, fusional reserves, and simultaneous vision. A method for treating such patients has been developed, which aims for improvement of the blood supply to the ciliary muscle, accommodation reflex, visual acuity and differential sensitivity of the retina, vergence and version accommodation tonicity, convergence and fusion ability. The treatment led to normalization of absolute and relative accommodation, and increase of fusional reserves. The character of vision became binocular, asthenopic complaints stopped. The 'anlauf' glasses allow long-term preservation of the effect of received treatment, as well as prevention of visual disturbances in eye-straining work. CONCLUSION: The complex approach to the treatment of patients with spasms, pareses and paralyses of accommodation leads to restoration of the functions of visual analyzer in fairly short time (15-20 sessions).

Objective estimation of fusional reserves using infrared eye tracking: the digital fusion-range test.

CLINICAL RELEVANCE: Horizontal fusional reserves are used in the diagnosis and monitoring of common vergence disorders, such as convergence insufficiency, which can cause asthenopia and impact near work. Infrared eyetracking technology shows promise for obtaining automated and objective measurements of fusional reserves, expanding options for screening, clinical testing, and at-home monitoring/vision training. BACKGROUND: Current clinical tests for fusional reserves rely on subjective judgements made by patients (for diplopia) and clinicians (for eye movements). This paper describes an objective and automated "digital fusion-range test" pilot-tested in adults without current eye disease or binocular vision anomalies. This test combines a consumer-grade infrared eyetracker, a dichoptic display, and custom analyses programs to measure convergence and divergence reserves. METHODS: Twenty-nine adult participants completed the study. Horizontal fusional reserves at 55 cm were measured using prism bars and with our computer-based digital fusion-range test. For the digital test, observers viewed dichoptic targets whose binocular disparity modulated over time (at speeds of 0.5, 1.0, or 2.0 Δ/s) while their eye movements were continuously recorded. Subjective reports of break and recovery (by keyboard button press) were compared to objective estimates extracted from eyetracking recordings (via automated analyses). RESULTS: Objective and subjective measures of break and recovery agreed closely. Clinically small (0.3-2Δ) but statistically significant (p < 0.012) differences were found between measurement types for divergence breaks/recoveries and convergence recoveries. No significant differences were found for convergence breaks (p = 0.11). Such differences are consistent with an average 0.91 (SD 1.66) seconds delay between objective break/recovery and subjective responses. The digital test produced comparable results to the standard clinical prism bar method. CONCLUSION: The digital fusion-range test supports an automated, reliable assessment of horizontal fusional reserves, which do not depend on subjective responses. This technology may prove useful in a variety of clinical and community-based settings.

Effect of Induced Vertical Disparity on Horizontal Fusional Reserves.

PURPOSE: The aim of this study was to investigate the effects of induced vertical disparity on horizontal fusional reserves at near. MATERIALS AND METHODS: In 170 healthy subjects wearing best corrective refraction, the negative and positive horizontal fusional reserves were measured with base-in (BI) and base-out (BO) prisms, respectively, in the presence of 0.5 prism diopters (∆) and 1∆ vertical prisms placed in trial frames in front of the right eye. The prism power was slowly increased step by step until the subject reported sustained blur, break, and recovery. These were compared to horizontal fusional reserves in the same subjects without a vertical prism. Data were analyzed in SPSS.17 software using a repeated measures ANOVA. RESULTS: Induced vertical disparity decreased negative fusional reserves (NFR) horizontally and was more significant with 1∆ vertical disparity (P<0.001). There were significant differences between the blur (P<0.001), break (P<0.001), and recovery (P<0.001) for NFR before and after induced vertical disparity and no significant difference between blur (P=0.173) and recovery points (P=0.261) with a marginal difference for break points (P=0.045) for the positive fusional reserves (PFR). CONCLUSION: Inducing vertical disparity even with small magnitudes affects all 3 aspects (blur, break, and recovery) of horizontal negative fusional reserves while only break is affected in positive fusional reserves. These changes are statistically significant but do not seem to be clinically significant except for cases accompanied by symptoms.