# Associations between Progression of Retinal Pigment Epithelial and Outer Retinal Atrophy and Choroidal Thickness: A 2-Year observation

## TL;DR

This study found that retinal atrophy progression is linked to thinner choroid and other factors, leading to faster vision loss in older patients.

## Contribution

The study identifies risk factors for rapid retinal atrophy progression and links them to choroidal thickness and other baseline characteristics.

## Key findings

- Baseline choroidal thickness negatively correlates with retinal atrophy progression.
- Thinner choroid, subretinal drusenoid deposits, and drusen increase the risk of rapid retinal atrophy.
- Pachychoroid characteristics are protective against retinal atrophy progression.

## Abstract

To evaluate the clinical course of retinal pigment epithelial and outer retinal atrophy (RORA) with best-corrected visual acuity (BCVA) and risk factors for rapid progression to explore the pathogenesis.

Retrospective observational study.

Data on eyes with fovea-involved RORA associated with age-related macular degeneration were collected over time from 10 hospitals in Japan.

Data on ophthalmic examination, BCVA, and OCT images were analyzed.

Relationships between changes in BCVA and extents of RORA and outer plexiform layer (OPL) deterioration and their associations with central choroidal thickness (CCT) and pachychoroid characteristics at baseline were evaluated.

Of the 53 eyes of 53 patients (mean age; 74.9 ± 1.4 years), 32 eyes (60.4%) belonged to men. The progression in the mean extent of OPL deterioration was evident at year 1, whereas that of RORA, BCVA impairment, thinning of the central retinal thickness, and CCT became apparent at year 2 (P < 0.05). Changes in the extents of RORA and OPL deterioration and BCVA were correlated (P < 0.05). Baseline CCT negatively correlated with baseline RORA and the changes in extent of RORA (P < 0.05). After adjusting for age and sex, a longer extent of RORA at baseline predicted BCVA worsening ≥0.04 per year (odds ratio [OR], 3.444; 95% confidence interval [CI], 1.015–11.691; P = 0.047). Greater horizontal extension of RORA ≥175 μm/y was frequently observed in eyes with thinner CCT <180 μm (OR, 4.684; 95% CI, 1.288–17.036; P = 0.019), subretinal drusenoid deposits (SDDs) (OR, 6.714; 95% CI, 1.555–28.988; P = 0.011), and drusen (OR, 4.392; 95% CI, 1.176–16.410; P = 0.028) and less observed in eyes with pachychoroid characteristics (OR, 0.038; 95% CI, 0.003–0.454, P = 0.010) at baseline after adjusting for age and baseline extent of RORA; similar risks for greater vertical extension of RORA were observed.

The change in BCVA paralleled the changes in the extents of RORA and OPL deterioration. Rapid BCVA impairment was observed in eyes with longer RORA at baseline. A thinner choroid, SDD, and drusen were risk factors, and pachychoroid characteristics were protective factors against RORA progression. Further studies are warranted to better understand the progression of RORA and vision loss.

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