Coats' Disease Diagnosed During Adulthood.

Coats' disease is an idiopathic non-hereditary condition first described by Coats in 1908 as a congenital retinal telangiectatic and aneurysmal disease associated with retinal exudation. Its presentation is classically in early childhood. We report a rare case of Coats' disease that first presented during adulthood in a 35-year-old male. The patient presented with visual loss in the left eye for two months. His visual acuity was counting fingers in the left eye and fundus examination revealed extensive lipid exudation in the macula with telangiectatic vessels and microaneurysms with vascular malformation in the inferotemporal quadrant. Fluorescein angiography showed leakage from the telangiectatic vessels, and optic coherence tomography showed significant macular edema. A provisional diagnosis of adult-onset Coats' disease was made. The patient responded well to intravitreal ranibizumab injections for macular edema and sectoral argon laser photocoagulation for peripheral vascular abnormalities. This case is unusual in adulthood onset and the first presentation was during adulthood in the third decade of life in contrast to the typical age of onset which is younger than five years.