Photopic and scotopic multifocal pupillographic responses in age-related macular degeneration

Abstract

We compared photopic and scotopic multifocal pupillographic stimuli in age-related macular degeneration (AMD). Both eyes of 18 normal and 14 AMD subjects were tested with four stimulus variants presented at photopic and 126 times lower luminances. The multifocal stimuli presented 24 test regions/eye to the central 60° The stimulus variants had two different check sizes, and when presented either flickered (15. Hz) for 266. ms, or were steady for 133. ms. Mean differences from normal of 5 to 7. dB were observed in the central visual field for both photopic and scotopic stimuli (all p< 0.00002). The best areas under receiver operating characteristic plots for exudative AMD in the photopic and scotopic conditions were 92.9. ± 8.0 and 90.3 ± 5.7% respectively, and in less severely affected eyes 83.8 ± 9.7% and 76.9 ± 8.2%. Damage recorded at photopic levels was possibly more diffusely distributed across the visual field. Sensitivity and specificity was similar at photopic and scotopic levels.