AUTOMATED PUPIL PERIMETRY IN AMBLYOPIA - GENERALIZED DEPRESSION IN THE INVOLVED EYE

Objective: This study was designed to determine whether the relative a fferent pupillary defects observed commonly in amblyopic eyes are asso ciated with a uniform depression of the pupillary light reflex through out the visual field or solely by a focal decrease in pupillary respon se near fixation. Design: The authors used pupil perimetry to evaluate the contraction amplitude of the pupil in response to focal light sti muli at 76 points throughout the 30 degrees field in each eye of 28 pa tients with amblyopia. The ''pupil fields'' were recorded using a comp uterized infrared pupillograph linked to a Humphrey Field Analyzer, so that the pupil contraction could be recorded in response to perimetri c light stimuli. Participants: Nine patients had strabismic amblyopia, ten had anisometropia, six had a combination of anisometropia and str abismus, and three had deprivation amblyopia due to monocular congenit al cataract. Main Outcome Measures: Mean pupillary contraction amplitu de for the entire field and focal amplitudes at each tested location w ere compared. Mixed-model analysis of variance was used to assess effe cts of perimetry location, type of amblyopia, and interaction effects. Results: The overall average of all the pupil contractions throughout the 30 degrees field was less for the amblyopic eye compared with tha t of the fellow eye. This decrease in focal pupil response for amblyop ic eyes was present in each type of amblyopia and was greatest for dep rivation amblyopia. The contraction amplitude was depressed diffusely throughout the pupil field and showed neither focal deficits nor a sel ective depression about fixation. Conclusion: Amblyopia produces a glo bal depression of focal pupillary responses across the entire 30 degre es field.