Stereoacuity Improvement using Random-Dot Video Games

Conventional amblyopia therapy involves occlusion or penalization of the dominant eye, though these methods enhance stereoscopic visual acuity in fewer than 30% of cases. To improve these results, we propose a treatment in the form of a video game, using random-dot stimuli and perceptual learning techniques to stimulate stereoacuity. The protocol is defined for stereo-deficient patients between 7-14 years of age who have already received treatment for amblyopia and have a monocular best corrected distance visual acuity of at least 0.1 logMAR. Patients are required to complete a perceptual learning program at home using the video game. While compliance is stored automatically in the cloud, periodic optometry center visits are used to track patient evolution and adjust the game's stereoscopic demand until the smallest detectable disparity is achieved. The protocol has proved to be successful, and effectiveness is gauged in terms of a two-level gain on a random stereoacuity test (global stereoacuity or cyclopean stereoacuity reference test). Moreover, the random-dot stimuli learning transfers to medial lateral stereoscopic acuity according to a Wirt Circles test, in which success criteria is a final stereoacuity of over 140", and the attained enhancement corresponds to no less than two levels of stereoscopic acuity. Six months later, a random-dot stereoacuity test recorded no reduction in the stereoacuity that was achieved

Combined passive and active treatment in strabismic amblyopia with accommodative component

Background: Treatment of amblyopia in esotropic subjects with accommodative component currently consists of optical correction and subsequent occlusion, or penalisation, of the dominant eye. This treatment obtains a good outcome in visual acuity but poor outcomes in binocular vision. An intervention protocol that could improve the outcome of conventional treatment is presented. Methods: A retrospective study in subjects with amblyopia associated with both fully accommodative and partially accommodative esotropia is presented. Subjects were refracted under cycloplegia and treated with occlusion (passive therapy). Subjects who did not achieve orthotropia through optical correction (partially accommodative esotropia) performed an active therapy (full‐time prismatic correction and subsequent fusional vergence therapy or surgery in larger angles > 12 prism dioptres). After treatment, the subjects were examined by a masked optometrist in an external ophthalmology clinic. Results: Twenty‐six subjects (12 males and 14 females) aged from six to 13 years (median 8.50; interquartile range [IQR] 3) were included. Median age of detection was three years (IQR 1). All the subjects were hyperopic. In the baseline, median best‐corrected visual acuity of the amblyopic eye was 0.40 logMAR (IQR 0.30) and 0.00 logMAR (IQR 0.01) in the dominant eye. After the treatment, the median best‐corrected visual acuity in the amblyopic eye was 0.06 logMAR (IQR 0.08). These differences were statistically significant (p < 0.001). All subjects acquired stereoacuity equal or better than 800′′ with the Randot Preschool Stereoacuity Test. Conclusions: The proposed treatment highlights the management of amblyopia in esotropic subjects with accommodative component. This intervention protocol could help to determine if the treatment has to be passive (in fully accommodative esotropia) or a combination of passive and active therapies (in partially accommodative esotropia)

Predictive factors for the perceptual learning in stereodeficient subjects

Background: Stereopsis is a valuable feature of human visual perception which is critically impaired in amblyopia, but can be improved through perceptual learning (PL). This article aims to determine the variables affecting the outcomes and intensity of a stereoacuity stimulation program. Methods: Re-analysis of a previous study in stereodeficient subjects with a history of amblyopia. Sixteen subjects (12 females, 4 males) aged between 7 and 14 received stereopsis stimulation through a PL program at home. A correlation analysis evaluated whether treatment intensity or percentage improvement were related to age or baseline stereoacuity measurements. Further analysis was performed to assess whether the type of amblyopia conditioned the PL treatment (Fischer Statistical Test). Results: No significant correlation was found between age and percentage improvement (rho = −0.08, p = 0.749), nor was age correlated with treatment intensity (rho = 0.170, p = 0.544). However, a correlation did exist between baseline stereoacuity levels and treatment intensity (rho = 0.734, p = 0.001). Baseline stereoacuity and percentage improvement had a negative correlation (rho = −0.748, p = 0.005), while treatment intensity showed only a weak association with the type of amblyopia (p = 0.064). Conclusions: Present results suggest that perceptual learning in stereodeficient subjects is not influenced by either the subject's age or the type of amblyopia. Baseline stereoacuity, on the other hand, seems to be a predicting factor for perceptual learning outcomes. According to our study, subjects with poor basal stereoacuity needed more sessions to improve and their percentage improvement was lower. However, due to the reduced size of the sample, the results should be considered with caution.This research was carried out thanks to a grant awarded by the European University of Madrid 2013/UEM20; to JR-A