Abstract
Purpose :
Adaptative Optics Transscleral Flood Illumination (AO-TFI) is a new technology 1 that allows studying retinal structure in vivo, providing cellular level images of the retina. The aim of this study was to evaluate cellular images in patients with inherited macular dystrophy.
Methods :
Macular AO-TFI images (FOV of 6.7° x 6.7°) were acquired using Cellularis Discovery (EarlySight SA, Geneva, Switzerland). Quantitative analyses using proprietary software were performed to capture the hyper-reflectivity of the photoreceptor (PR) and the hypo-reflectivity of the retinal pigment epithelium (RPE). Descriptive statistics were then employed to compare PR and RPE characteristics between healthy and IRDs. Four patients with macular dystrophy related to ABCA4 (n = 3) or CDHR1 (n= 1) were included in the study. Multimodal imaging and visual function tests were obtained from all patients.
Results :
In ABCA4 patients, RPE cell density measured with Voronoi ranged 527-4005 cell/mm2 (versus normal mean 4887 cell/mm2 SD 454), hyper-reflective regions at the PR layer ranged 472-1720 cell/mm2 (versus normal mean 30000 cell mm2). In CDHR1, l hypo reflective regions at the RPE layer ranged 727-902 cell/mm2, macular cones ranged 511-561 cell/mm2.
Conclusions :
By using Cellularis, foveal RPE cells are observed and quantified, macular cones are observed and quantified. Quantification of hypo reflective regions for RPE layer and hyper reflective regions for PR layer could be a mean to compare healthy vs non healthy when Voronoi analysis cannot be used.
1 Kowalczuk L, Dornier R, Kunzi M, et al. In Vivo Retinal Pigment Epithelium Imaging using Transscleral Optical Imaging in Healthy Eyes. Ophthalmol Sci. 2022 Oct 19;3(1):100234.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.