Abstract
Purpose :
Adaptive optics (AO) technology allows us to visualize photoreceptors, in particular cones, on a cellular level. Early changes identified on AO imaging could serve as potential biomarkers for clinical studies. In this descriptive cross-sectional study, we present the first results of AO images in patients with early-onset macular degeneration (EOMD), and try to correlate the results from multimodal imaging with functional parameters.
Methods :
EOMD patients were defined as having any age-related macular degeneration phenotype before the age of 55 years. Images were made using the rtx1 AO Retinal Camera (Imagine Eyes, Orsay, France). A 19-loci template, covering the macular region both horizontally and vertically, was used as a standard template (Figure 1), adding extra targets based on individual phenotypical characteristics of patients. Multimodal imaging (optical coherence tomography (OCT), color fundus photography and fundus autofluorescence), and retinal sensitivity (RS) using mesopic microperimetry (MP) were used for interpretation of AMD characteristics, lesion localization and functional consequences. MP images were attempted to overlap with AO images as precisely as manually possible, to correlate RS and AO structures in a point-to-point manner.
Results :
Twenty-four EOMD patients (48 eyes; median age 53.6) were included. 13/46 eyes had geographic atrophy (GA). Areas of drusen in EOMD patients, observed on OCT scans, corresponded with cloudy areas on AO images, accompanied by a decrease or total loss of cone mosaic (Figure 2). GA areas were characterized by inhomogenous, high-contrast hyperreflective areas with loss of cone mosaic and deposition of hyporeflective clumps. Evaluation of RS in AO images in areas of decreased cone mosaic showed that this decrease did not always result in a reduced RS.
Conclusions :
Our resulting AO images of drusen and GA areas in EOMD patients is similar to previous studies describing AMD characteristics using AO (Paques et al., 2018). Decreased visualization of cones in drusen areas may be due to cone loss or an altered cone orientation. We could not correlate changes on AO with reduced in RS in this study. Future studies, with a larger dataset and preferably an evaluation of these characteristics over time, will help in a more profound interpretation of these images and may lead to new biomarkers that could potentially serve as suitable clinical trial endpoints for AMD.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.