Comparison of Optical Coherence Tomography With Fundus Photographs, Fluorescein Angiography, and Histopathologic Analysis in Assessing Coats Disease.

Importance: Coats disease is a rare pediatric vitreoretinopathy that can cause devastating visual and anatomic outcomes. Objective: To compare optical coherence tomography (OCT) with fundus photographs, fluorescein angiography (FA), and histopathologic findings in Coats disease. Design, Setting, and Participants: This retrospective cohort study was conducted in a single tertiary institution (Duke Eye Center) and identified 28 children with Coats disease through a review of medical records from December 2002 to January 2018. Four eyes were obtained from a biorepository for histopathologic analysis. Main Outcomes and Measures: Macular OCT, fundus photographs, and FA results were reviewed and compared for morphological changes. These were compared with retinal histopathological findings. Results: The mean (SD) age was 9.5 (5.5) years for the 28 children (and 29 eyes) with clinical imaging results, and 24 (86%) were boys. A comparison between imaging modalities revealed OCT features that were not visible in photographs or FA, including exudates in multiple retinal layers (23 [82.1%]), small pockets of subretinal fluid (4 [14.3%]), an outer retinal atrophy overlying fibrotic nodules (7 [25.0%]), and small preretinal hyperreflective OCT dots (25 [89.3%]). Next, a comparison with light micrographs introduced an association of OCT findings with possible pathological features, including hyperreflective linear structures on OCT that appeared consistent with cholesterol crystals, small hyperreflective dots with macrophages, outer retinal tubulations with rosettes, and analogous OCT histopathology features such as intraretinal vessels entering fibrotic nodules and retinal pigment epithelium excrescences under the subretinal fluid. An OCT analysis revealed intraretinal cystoid spaces in 19 eyes, but in 9 of 19 (47.4) this was not associated with cystoid macular leakage; rather, fluorescein leakage was observed from peripheral telangiectatic vessels. Additionally, exudates were intraretinal only (6 [21.4%]) or both intraretinal and subretinal (17 [60.7%]); none were subretinal only. In eyes with follow-up results, new fibrosis developed in 8 of 17 eyes (47.1%). Fibrosis developed in 5 of 5 eyes (100%) with baseline subretinal fluid vs 3 of 12 without (25%; 95% CI, 22%-92%) and in 7 of 9 eyes (77.8%) with subretinal exudates vs 1 of 8 (12.5%) without (95% CI, 16%-89%). Conclusions and Relevance: Optical coherence tomography may show the transient and permanent effects of Coats disease on the retina. These results suggest that exudates and fluid in the macular subretinal space appear later in the disease and may result in fibrosis formation. Further studies are needed to confirm if early treatment could prevent vision-threatening macular fibrosis.