Spontaneous Branch Retinal Artery Occlusion Secondary to Aneurysmal Fibrosis in an Adult with Coats Disease: A Case Report.

PURPOSE: To describe a case of branch retinal artery occlusion (BRAO) in an adult with Coats disease, documented using ultra-widefield fluorescein angiography (UW-FA).

METHODS

Observational case report with longitudinal evaluation using optical coherence tomography (OCT) and ultra-widefield fluorescein angiography.

RESULTS

A 21-year-old male with a childhood diagnosis of Coats disease presented with recalcitrant macular edema and best-corrected visual acuity (BCVA) of 6/40 in the right eye. Baseline UW-FA demonstrated multiple microaneurysms and a patent, tortuous temporal arteriole with focal aneurysmal distention. At a 10-month follow-up, the patient's BCVA remained entirely unchanged. However, repeated UW-FA revealed a new extensive area of retinal nonperfusion extending from the temporal macula to the periphery. Comparison with baseline imaging identified that the previously patent arteriole had become completely occluded at the site of the proximal aneurysm. The absence of prior laser application at this specific site confirms that the subsequent fibrotic closure and arterial occlusion were entirely spontaneous.

CONCLUSION

Sudden arterial occlusion may occur in adult Coats disease due to spontaneous aneurysmal fibrosis. This highlights a vascular remodeling pathway distinct from classic exudative progression. Ultra-widefield imaging may aid in detecting and monitoring these ischemic changes.