Characteristics of Rare Inherited Retinal Dystrophies in Adaptive Optics—A Study on 53 Eyes

Inherited retinal dystrophies (IRDs) are genetic disorders that lead to the bilateral degeneration of the retina, causing irreversible vision loss. These conditions often manifest during the first and second decades of life, and their primary symptoms can be non-specific. Diagnostic processes encompass assessments of best-corrected visual acuity, fundoscopy, optical coherence tomography, fundus autofluorescence, fluorescein angiography, electrophysiological tests, and genetic testing. This study focuses on the application of adaptive optics (AO), a non-invasive retinal examination, for the assessment of patients with IRDs. AO facilitates the high-quality, detailed observation of retinal photoreceptor structures (cones and rods) and enables the quantitative analysis of parameters such as cone density (DM), cone spacing (SM), cone regularity (REG), and Voronoi analysis ([Formula: see text]). AO examinations were conducted on eyes diagnosed with Stargardt disease (STGD, [Formula: see text]), cone dystrophy (CD, [Formula: see text]), and cone-rod dystrophy (CRD, [Formula: see text]), and on healthy eyes ([Formula: see text]). There were significant differences in the DM, SM, REG, and [Formula: see text] parameters between the healthy and IRD-affected eyes ([Formula: see text] for DM, SM, and REG; [Formula: see text] for [Formula: see text]). The mean DM in the CD, CRD, and STGD groups was 8900.39/mm [Formula: see text] , 9296.32/mm [Formula: see text] , and 16,209.66/mm [Formula: see text] , respectively, with a significant inter-group difference ([Formula: see text]). The mean SM in the CD, CRD, and STGD groups was 12.37 [Formula: see text] m, 14.82 [Formula: see text] m, and 9.65 [Formula: see text] m, respectively, with a significant difference observed between groups ([Formula: see text]). However, no significant difference was found in REG and [Formula: see text] among the CD, CRD, and STGD groups. Significant differences were found in SM and DM between CD and STGD ([Formula: see text] for SM; [Formula: see text] for DM) and between CRD and STGD ([Formula: see text] for SM; [Formula: see text] for DM). Our findings suggest that AO holds significant potential as an impactful diagnostic tool for IRDs.