Dark-rearing promotes drastic improvement of visual acuity in the amblyopic eye of lid-sutured kittens

Abstract

This report extends findings (Duffy & Mitchell, 2013) of a dramatic recovery of vision in the deprived eye of amblyopic kittens following a short ‘dark-pulse’ (a 10 day period of darkness) to situations of clinical relevance. To this end, the initial deprivation began at post-natal day 7 rather than post-natal day 30. As before, the dark-pulse was imposed either immediately after the initial monocular deprivation, or was delayed several weeks after stable amblyopia was establsihed. In some animals, this dark-pulse was shortened, or disrupted by short periods of daily binocular visual experience. The effects on the visual acuity and alignment acuity of the two eyes were documented as well as the effects on binocular depth perception. The benefits of a short dark-pulse were identical to those of the prior study. A dark-pulse of 5 days was ineffective as was a dark-pulse interrupted daily by light for 30-minutes.