Impairments in Dark Adaptation Are Associated with Age-Related Macular Degeneration Severity and Reticular Pseudodrusen

Purpose We investigate whether ocular and person-based characteristics were associated with dark adaptation (DA). Design Cross-sectional, single-center, observational study. Participants One hundred sixteen participants older than 50 years of age with a range of age-related macular degeneration (AMD) severity. Methods Participants underwent best-corrected visual acuity (BCVA) testing, ophthalmoscopic examination, and multimodal imaging. Presence of reticular pseudodrusen (RPD) was assessed by masked grading of fundus images and was confirmed with optical coherence tomography. Eyes also were graded for AMD features (drusen, pigmentary changes, late AMD) to generate person-based AMD severity groups. One eye was designated the study eye for DA testing. Nonparametric statistical testing was performed on all comparisons. Main Outcome Measures The primary outcome of this study was the rod intercept time (RIT), which is defined as the time for a participant's visual sensitivity to recover to a stimulus intensity of 5×10 −3 cd/m 2 (a decrease of 3 log units), or until a maximum test duration of 40 minutes was reached. Results A total of 116 study eyes from 116 participants (mean age, 75.4±9.4 years; 58% female) were analyzed. Increased RIT was associated significantly with increasing AMD severity, increasing age ( r = 0.34; P = 0.0002), decreasing BCVA ( r = −0.54; P P = 0.03), and decreasing subfoveal choroidal thickness ( r = −0.27; P = 0.003). Study eyes with RPD (15/116 [13%]) had a significantly greater mean RIT compared with eyes without RPD in any AMD severity group ( P Conclusions Impairments in DA increased with age, worse visual acuity, presence of RPD, AMD severity, and decreased subfoveal choroidal thickness. Analysis of covariance found the multivariate model that best fit the data included age, AMD group, and presence of RPD ( R 2 = 0.56), with the presence of RPD conferring the largest parameter estimate.