Abstract
Purpose :
The aim of this study was to investigate morphologic characteristics of the retina during drusen development in early and intermediate age-related macular degeneration (AMD) using spectral-domain optical coherence tomography (SD-OCT) images.
Methods :
15 eyes with early or intermediate AMD were scanned using Spectralis SD-OCT (scanning area 20°x20°, volume scan 1024x97) in a regular follow-up scheme every three months for at least one year. The standard EDTRS grid was centered on the fovea of the individual eyes and the drusen volume for each EDTRS-field was segmented by a software automatically. Two expert graders reviewed the each B-scans of the volume scans. The presence of pseudodrusen, RPE-migration, hyperreflective material inside drusen and vortexing of the internal retinal layers was noted, and the integrity of the RPE-layer as well as of the ELM and IS-OS-layer was evaluated and, if an atrophy/absence of one of those layers was observed, the area of absence was segmented manually.
Results :
15 eyes were evaluated in this project. Progression of the drusen volume was observed in all eyes, as well as a spontaneous regression. Interestingly, drusen regression and progression can occur simultaneoulsy within different areas of the retina, and small distinct drusen regression events are often overrode by a much more substantial progression. During regression of drusen volume, as seen in the individual EDTRS-fields, migration of RPE cells was observed frequently (p<0.001), as well as vortexing of the internal retinal layers (p<0.001), hyperreflective material inside of drusen (p<0.001) and a beginning atrophy of the RPE layer as well as a dissolving ELM (p<0.05 and 0.01, resp.). However, only the development of hyperreflective material inside drusen seem to precede a drusen volume regression (p<0.001).
Conclusions :
Eyes in early AMD show a dynamic modeling of drusen, and progression as well as regression of drusen volume can occur simultaneously in the same eye. The evolving of certain characteristics are related to a regression of drusen volume, and further research might unveil their significance as biomarkers for progression of AMD.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.