Adaptive optics phenotypes of intermediate age-related macular degeneration

Abstract

Purpose : To describe the microscopic characteristics of known lesions associated with intermediate age-related macular degeneration (AMD) on adaptive optics ophthalmoscopy (AOO) imaging and their correlation to other multimodal imaging methods.

Methods : Patients with intermediate AMD were enrolled in an observational longitudinal multicenter cohort to decipher the natural history of the disease. Participants underwent spectral-domain optical coherence tomography (SD-OCT), infrared scanning laser ophthalmoscopy (IR-SLO), and fundus autofluorescence (FAF) imaging using the Spectralis device (Heidelberg Engineering, Germany). Flood-illumination AOO images were acquired using the commercially available rtx1 camera (Imagine Eyes, France). AO image mosaics were constructed using the montage function on the i2k Retina AO software (DualAlign LLC, USA). En face and/or cross-sectional images across modalities were manually aligned to perform intra- and inter-modality comparisons of retinal lesions.

Results : Heterogeneity of drusen characteristics was observed on AOO. Typical large drusen were characterized by a hyper-reflective rim with central iso-reflectivity. The visibility of the cone photoreceptor mosaic was largely obliterated around and on top of these drusen. On the contrary, cone photoreceptors were visualised in another group of patients with smaller drusen that manifested on AO images as a hyper-reflective rim with internal hypo-reflectivity. Cone visibility on AO correlated with the presence of interdigitation zone on OCT B-scans. Subretinal drusenoid deposits (SDD) typically displayed hypo-reflective circles surrounding areas of iso-reflectivity on AO images. Early stages of the SDD appeared as an ill-defined area of hypo-reflectivity. Several distinct phenotypes of retinal pigment epithelium and outer retinal atrophy were identified on AOO. Variability in the focusing depth can significantly alter the appearance and interpretation of AO images.

Conclusions : We describe various phenotypes of intermediate AMD on adaptive optics ophthalmoscopy, showing distinct patterns, which correlate with known morphologic presentations on multimodal imaging. The significance of the described changes is yet to be determined in large longitudinal cohort studies.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.