Researchers recently found that drusen and hyperreflective foci (HRF) represented imaging biomarkers of disease progression in AMD and demonstrated distinct topographic patterns over time that differed between eyes progressing to macular neovascularization or macular atrophy and eyes without disease progression.

This cohort study evaluated monthly images, taken over two years, for 518 patients with early or intermediate AMD in the fellow eye. During the 24-month follow-up period, 26% of eyes developed macular neovascularization, 10% developed macular atrophy and 64% did not progress to advanced AMD.

The investigators observed drusen and HRF with distinct topographic patterns, with mean drusen thicknesses at the fovea ranging from 29.6μm for eyes progressing to macular neovascularization to 17.2μm for eyes progressing to macular atrophy and 17.1μm for eyes without disease progression. At 0.5mm eccentricity, they noted that mean drusen thicknesses were 25.8μm, 21.7μm and 14.4μm, respectively.

As for mean HRF thicknesses at the foveal center, they measured 0.072μm, 0.059μm and 0.044μm, respectively. At 0.5mm eccentricity, they added that the largest mean HRF thickness was in eyes progressing to macular atrophy (0.227μm), followed by eyes progressing to macular neovascularization (0.161μm) and eyes without disease progression (0.085μm).

“Automated localization and precise quantification of these factors may help to develop reliable methods of predicting future disease progression,” the study authors concluded in their paper.