Hyporeflective Cores within Drusen: Association with Progression of Age-Related Macular Degeneration and Impact on Visual Sensitivity

Purpose: To examine the association between hyporeflective cores within drusen (HCD) and disease progression in age-related macular degeneration (AMD) and with visual function.

Design: Longitudinal observational study.

Participants: Two hundred and eighty eyes from 140 participants with bilateral large drusen, without late AMD.

Methods: Multimodal imaging and microperimetry were performed at baseline and subsequently every 6 months for up to 3 years. Baseline OCT scans were graded for the presence of HCD and used to calculate drusen volume. The total area of the drusenoid lesions containing hyporeflective cores (HCD extent) on color fundus photographs (CFPs) was calculated. CFPs were also graded for the presence of pigmentary abnormalities. The association between HCD extent with progression to late AMD (including OCT signs of atrophy) and visual sensitivity measured using microperimetry at baseline and its rate of change over time was evaluated with and without adjustment for confounders of drusen volume, pigmentary abnormalities, and age.

Main outcome measures: Time to develop late AMD and visual sensitivity.

Results: Twenty (7%) eyes from 12 (9%) individuals were found to have HCD at baseline, which was associated with a nonsignificantly increased rate of progression to late AMD (unadjusted P = 0.050). HCD extent was significantly associated with an increased rate of progression to late AMD (unadjusted P = 0.034) and lower visual sensitivity at baseline (unadjusted P < 0.001). However, these associations were no longer significant (P ≥ 0.264 for both) after adjusting for known risk factors for AMD progression. HCD extent was also not associated with a faster rate of visual sensitivity decline before the development of late AMD, with or without adjustment (P ≥ 0.674 for both). Increasing age and larger drusen volume were associated with HCD extent (P ≤ 0.041).

Conclusions: In a cohort with bilateral large drusen, HCD presence and extent were not independently associated with an increased rate of progression to late AMD over 3 years, nor with lower visual sensitivity or an increased rate of visual sensitivity decline before the development of late AMD, after adjusting for known risk factors for disease progression.