Processing Delays in Amblyopic Eyes

Saccadic latencies were measured in amblyopes with constant strabismus, amblyopes without strabismus, and intermittent strabismics with or without amblyopia. Subjects tracked a small spot of light, either monocularly or binocularly, which moved with random horizontal step displacements of 0.25–8.5 deg over the central field. Increased saccadic latencies were observed in the amblyopic eyes of 6 of 11 subjects, with or without strabismus; saccadic latencies were similar in each eye of 2 subjects having intermittent strabismus without amblyopia. Amblyopia was a necessary condition for increased saccadic latencies and not strabismus. Evidence for normal motor control of eye movements in amblyopic subjects is as follows: normal saccadic durations in the amblyopic eyes, normal saccadic‐latency distribution curves for binocular tracking and monocular tracking with the nonamblyopic eyes, and synchronous movements of the 2 eyes. Our results are interpreted in terms of a processing delay in the sensory pathways leading from the central region of the amblyopic eye to the centers involved in saccadic initiation.