Abstract
Purpose :
The aim of this prospective study was to analyze the development of retinal characteristics including drusen volume changes over time of eyes with early and intermediate AMD using validated automated algorithms, in order to determine their relevance for drusen regression.
Methods :
38 patients with early or intermediate AMD were scanned using Spectralis SD-OCT (scanning area 20°x20°, volume scan 1024x97) in a regular follow-up scheme of every three months. The standard ETDRS grid was centered on the fovea and the drusen volume for each ETDRS-field was automatically segmented. Subsequently, following morphologic characteristics were determined for their presence and number: Subretinal drusenoid deposits (SDD), hyperreflective foci (HRF), inhomogeneous drusen content (IHD), and discontinuities within the RPE and IS-OS layer.
Results :
58 eyes of 38 patients were observed for a mean period of 32.2 months. Drusen volume shows a significant growth over time in all patients. In 21 eyes of 18 patients, a drusen regression occurred during observation time. Drusen growth after regression was not significantly different compared to pre-regression-time. An accumulating number of SDD, IHD and HRF was observed over time in all eyes, however, the event of drusen regression did not show a significant alteration in number or post-regression growth of these features. Comparatively, the number of discontinuities within the RPE layer per eye grew significantly larger after drusen regression occurred.
Conclusions :
Regression of drusen volume is a common event during the course of AMD, and its mechanisms and relevance for disease progression is still not fully understood. Interestingly, after regression, drusen continue to develop with no alteration in growth rates, as most of the other morphologic characteristics do, with the exception of the development of atrophies. With this information, gained by using validated automated segmentation algorithms, a more refined model of drusen volume development in early to intermediate AMD can be constructed.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.