Cone Abnormalities in Fundus Albipunctatus Associated with RDH5 Mutations Assessed Using Adaptive Optics Scanning Laser Ophthalmoscopy – Accepted Manuscript

Abstract: Purpose: To assess macular photoreceptor abnormalities in eyes with fundus albipunctatus with RDH5 mutation by using adaptive optics scanning laser ophthalmoscopy (AO-SLO).Design: Prospective cross-sectional study.Methods: Ten eyes with fundus albipunctatus and 11 normal eyes underwent a full ophthalmologic examination, microperimetry, spectral-domain optical coherence tomography (SD-OCT), and imaging with a prototype AO-SLO system. Cone density and spatial organization of the cone mosaic were assessed using AO-SLO images. Statistical analysis was done using right eye per one patient.Results: Four patients had the same mutation in RDH5 (c.928delC/ insGAAG), and 1 patient had a novel mutation in RDH5 (c.718delG). AO-SLO revealed the presence of small patchy dark areas representing cone loss in the macula of all eyes with fundus albipunctatus, including eyes for which fundus photographs showed no macular abnormalities and SD-OCT did not reveal any visible defects in the photoreceptor layer. Compared to normal eyes, eyes with fundus albipunctatusdemonstrated significantly lower cone density in area at 0.5 mm from the center of the fovea (P =0.020). At 0.5 mm and 1.0 mm from the center of the fovea, eyes with fundus albipunctatus showed fewer cones with 6 neighbors (P = 0.041 and 0.006). AO-SLO revealed hyper-reflective mosaics surrounded by hypo-reflective rings in areas corresponding to the retinal flecks.Conclusions: Macular cone density is lower and the regularity of the macular cone mosaic spatial arrangement is disrupted in eyes with fundus albipunctatus. AO-SLO imaging is a sensitive quantitative tool for detecting photoreceptor abnormalities in eyes with fundus albipunctatus.