The effect of prolonged monocular occlusion on latent nystagmus in the treatment of amblyopia.
We recorded eye movements in 8 patients with latent nystagmus (LN) before and after 2 days of occlusion of the better eye. The slow-phase speed of the nystagmus (SPS) during fixation with the worse eye became lower after 2 days of occlusion of the better eye. However, the SPS during fixation with the better eye became higher after 2 days of occlusion of the better eye. The sum of SPS during fixation with the better eye and SPS during fixation with the worse eye remained the same. Oscillopsia complaints gradually disappeared over days during the occlusion. It seems likely that the alteration of the LN during prolonged monocular vision is caused by a slow-velocity bias of the neural integrator, a compensatory drift, generated by the flocculus using retinal-slip information. The difference between SPS during fixation with the better eye and SPS during fixation with the amblyopic eye in LN patients with amblyopia is probably also caused by this compensatory drift. As the compensatory drift changes its direction and magnitude slowly over days, it seems advisable to occlude the better eye in children with amblyopia and LN during days per week, and not during hours per day.
Simonsz
H J
HJ
Kommerell
G
G
D000221:Adaptation, Ocular; D000550:Amblyopia / Q000503:physiopathology* / Q000628:therapy; D002648:Child; D005133:Eye Movements; D005403:Fixation, Ocular; D006801:Humans; D009759:Nystagmus, Pathologic / Q000503:physiopathology*; D009988:Orthoptics