Peripheral Changes Associated With Delayed Dark Adaptation in Age-related Macular Degeneration

To study the association between peripheral changes in age-related macular degeneration (AMD) and dark adaptation (DA).

Prospective, cross-sectional study.

We recruited patients with AMD and a control group (>50 years) without any vitreoretinal disease. Ultra-widefield (UWF) pseudocolor and fundus autofluorescence (FAF) were obtained, and were assessed by 2 graders for the presence of several peripheral changes in perimacular, midperipheral, and far-peripheral zones. All participants were also imaged with 7-field color fundus photographs used for AMD staging (Age-Related Eye Disease Study classification system). Both eyes of study participants were tested with a dark adaptation (DA) extended protocol (20 minutes). Multilevel mixed-effect models (accounting for correlated outcomes between 2 eyes) were used for analyses.

We included 128 eyes (n = 72 patients), 75% with AMD and the remainder controls. The presence of reticular pigmentary changes in the midperipheral (ß = 4.3, P = .012) and far-peripheral zones (ß = 8.4, P < .001) was associated with delayed rod-intercept times (RITs), even after adjusting for confounding factors. The presence, number, and extent of peripheral classic drusen did not show a similar association (P ≥ .148). The presence of a mottled decreased FAF pattern in the midperipheral zone was also associated with prolonged RITs (β = 4.4, P = .031).

Our results suggest an association between DA and the presence of peripheral reticular pigmentary changes, as well as the presence of a peripheral mottled decreased FAF pattern. This provides new insights on the clinical significance of peripheral changes in AMD, and their contribution to impairments on DA.