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

Ophthalmology. 2015 Oct;122(10):2053-62. doi: 10.1016/j.ophtha.2015.06.023. Epub 2015 Aug 4.


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 < 0.0001), pseudophakia (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 < 0.02 for all comparisons), with 80% reaching the DA test ceiling.

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.

Publication types

  • Observational Study
  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cross-Sectional Studies
  • Dark Adaptation / physiology*
  • Female
  • Humans
  • Macular Degeneration / diagnosis
  • Macular Degeneration / physiopathology*
  • Male
  • Middle Aged
  • Multimodal Imaging
  • Ophthalmoscopy
  • Retinal Drusen / diagnosis
  • Retinal Drusen / physiopathology*
  • Severity of Illness Index
  • Vision Disorders / diagnosis
  • Vision Disorders / physiopathology*
  • Visual Acuity / physiology