Unusual Coats-like response in occlusive retinal periphlebitis

Coats-like response refers to a condition where abnormal telangiectatic retinal vessels and aneurysms associated with subretinal exudation are seen in the setting of other ocular or systemic diseases. So far, it has been described with various ocular disorders like retinitis pigmentosa, chronic ischemic branch retinal vein obstruction and pars planitis. A man in his 30s presented with a 1-month history of diminution of vision in the left eye. On examination, the left eye fundus showed extensive subretinal exudation along with evidence of old and recent periphlebitis. Fluorescein angiography revealed multiple telangiectatic vessels and peripheral aneurysms along with perivenular leak. Optical coherence tomography of the macula demonstrated cystoid oedema with subretinal fluid. The case was diagnosed as Coats-like response with occlusive periphlebitis and was successfully managed with oral steroids alone.