Choroidal Thinning, Presence of Drusen Risk Factors for Rapid Progression of RORA

In OCT images, choroidal hypertransmission becomes increasingly apparent with the progressive attenuation of photoreceptor and retinal pigment epithelial (RPE) cells. Therefore, an expert group developed RPE and outer retinal atrophy (RORA) criteria for defining atrophy on the basis of OCT findings.Researchers in Japan recently aimed to evaluate OCT image-based changes that show the progression of atrophic lesions and changes in BCVA in eyes with GA with or without pachychoroid characteristics over at least two years. They evaluated the associations between these changes and choroidal conditions. The study found that the change in best-corrected visual acuity (BCVA) paralleled changes in the extent of RORA and outer plexiform layer (OPL) deterioration. Rapid BCVA impairment was observed in eyes with longer RORA at baseline. A thinner choroid, subretinal drusen deposits (SDD) and drusen were risk factors, and pachychoroid characteristics were protective factors against RORA progression. These illustrations from the study present the researcher’s hypothesis concerning the pathogenesis of RPE and outer retinal atrophy according to choroidal conditions: (A) In the eyes with pachychoroid, extent of RORA was relatively short at baseline. At this timepoint, RPE and photoreceptor cell loss may not be extremely severe, and some of the RPE cells may have enlarged to compensate for the adjacent RPE cell loss. The microenvironment of the pachychoroid may slow the progressive vulnerability of the RPE and photoreceptor cells and extension of RORA. (B) In the eyes with thin choroid, the extent of RORA at baseline was already relatively long. Many RPE cells had been lost and adjacent ones may have enlarged to sustain a greater number of photoreceptor cells; the vulnerability may be advanced. As the RORA further progresses and extends, focal RPE and photoreceptor cell loss may be accelerated most likely due to advanced vulnerability, which leads to rapid progression. Photo: Nagai N, et al. Ophthalmol Sci. September 15, 2025. Click image to enlarge. This multicenter retrospective study, which was published in Ophthalmology Science, included Japanese patients with RORA from 10 hospitals in Japan. Patients with hereditary diseases, retinal vascular occlusion or fibrovascular pigment epithelial detachment were excluded.Of the 53 eyes of 53 patients who had fovea-involved RORA associated with age-related macular degeneration and were followed up for at least two years, 32 eyes (60.4%) belonged to men. At baseline, the mean age of the patients was 74.9 years, BCVA was 0.513 logMAR, the extents of RORA in horizontal and vertical OCT sections were 2,546µm and 2,346μm, respectively, the extents of OPL deterioration in horizontal and vertical sections were 1,511µm and 1,446μm, respectively, central retinal thickness (CRT) was 130μm and central choroidal thickness (CCT) was 202μm.Progression of OPL deterioration was apparent in year one, whereas that of RORA and BCVA impairment was evident in year two. The mean CRT and CCT were significantly reduced as early as the two-year timepoint.After adjusting for age and sex, a longer extent of RORA at baseline predicted BCVA worsening ≥0.04 logMAR per year (odds ratio; OR: 3.444). Greater horizontal extension of RORA ≥175μm/year was frequently observed in eyes with thinner CCT <180μm (OR: 4.684), SDD (OR: 6.714) and drusen (OR: 4.392) and less observed in eyes with pachychoroid characteristics (OR: 0.038) at baseline after adjusting for age and baseline extent of RORA; similar risks for greater vertical extension of RORA were observed.“The extension of OPL deterioration may indicate the loss of photoreceptor synapses, and reduction in CRT may predominantly indicate the loss of photoreceptor cell body,” the researchers suggested in their paper. “The resulting photoreceptor damages allowed hypertransmission of the OCT signals, indicating the development and progression of RORA.”The team concluded that “The insights from this study facilitate the understanding of the clinical characteristics and pathogenesis of GA.”Click here for the journal source. Nagai N, Shinoda H, Matsuara H, et al. Associations between progression of retinal pigment epithelial and outer retinal atrophy and choroidal thickness; two years observation. Ophthalmol Sci. September 15, 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.