The prognostic value of visual evoked response latency in the treatment of amblyopia caused by strabismus

Visual evoked response alterations and especially P100 latency were studied in 60 patents with amblyopia caused by strabismus. Patients were divided in two groups according to the mode of fixation of the strabismic eye. Group A included patients with eccentric fixation, and group B, patients with central fixation of the strabismic eye. In all cases visual evoked responses were recorded before and after a 6-month period during which the patients had full-time occlusion of the sound eye. In cases with eccentric fixation of the strabismic eye, P100 latency was more abnormal than in cases with central fixation. In cases where latencies are clearly abnormal before treatment, the prognosis is poor and the results after occlusion of the sound eye are unstable. In contrast, in the cases with normal or nearly normal visual evoked response latencies, the prognosis is better, and these eyes show satisfactory improvement of visual acuity.