Comparative study of binocular visual stimulation versus monocular occlusion therapy in children with amblyopia

Amblyopia is defined as a decrease in visual acuity in one eye caused by abnormal binocular interaction or occurring in one or both eyes as a result of patterned vision deprivation during visual immaturity, for which no cause can be detected during physical examination of the eye and which in appropriate cases is reversible by therapeutic measures. Most common cause of monocular amblyopia is anisometropia, i.e., difference of refractive error between both eyes.

Currently the therapy for amblyopia includes passive monocular approaches like occlusion of the better eye full time or part time (6 hours or 2 hours daily) or pharmacological penalisation using a cyclopagic agent such as atropine, so that the amblyopic eye receives more stimulation and visual acuity improves.

Recently a binocular approach for treatment of amblyopia has been reported. here both the eyes are presented with a different stimulus i.e., dichoptic stimuli. contrast level is kept higher in the amblyopic eye to give it advantage over the good eye and thus to overcome suppression, while encouraging simultaneous use of both the eyes. Multiple ipad, ipod, smartphone and computer video games has been devised based on this principle. One such game is dichoptic version of tetris or falling blocks game which has to be played wearing red green anaglyph glasses. the fallingblocks are seen by one eye and  the landed blocks are seen by the other eye. contrast can be adjusted as per the need.

The main aim of this study is to compare the final visual outcome in the amblyopic eye in terms of best corrected visual acuity between two group of patients having anisometropic amblyopia, one group playing binocular tetris video game for 2 hours daily, 7 days a week for 3 months and the second group using patching over the amblyopic eye for 6 hours a day, 7 days a week for three months.