Eales' disease with secondary coats'-like reaction: a case report

Eales' disease is an idiopathic, inflammatory condition characterized by peripheral retinal phlebitis, distal non-perfusion, and neovascularization. Coats' disease, on the other hand, is an idiopathic, retinal vasculopathy characterized by telangiectasia and yellowish exudation. Both diseases commonly affect males. Here, we report an atypical case of unilateral Eales' disease with co-existing, secondary Coats'-like reaction in a 25-year-old male exhibiting unilateral retinal telangiectasia accompanied by subtle macular edema, extensive peripheral vascular sheathing, and distal non-perfusion in the absence of clinically visible exudation.

Case report.

A 25-year-old male presented with painless blurring of vision in the right eye for two months. Best-corrected Snellen visual acuity was 3/60 in the affected eye, with relative afferent pupillary defect observed, and 6/9 contralaterally. Anterior segment examination was unremarkable. Right eye fundoscopy showed aneurysmal telangiectasia at the macula, 360 degrees perivascular sheathing and telangiectasia of peripheral retinal vessels. There was no exudation, neovascularization, tractional membranes, vitritis, retinitis, and choroiditis. Left eye fundus was unremarkable. Optical coherence tomography of the macula revealed disorganization and thinning of the inner retinal layers with minimal intraretinal fluid. Fundus fluorescein angiography showed leakage from the aneurysms but not from the sheathed vessels, and an enlarged foveolar avascular zone. A well-defined zone of non-perfusion and retinal vascular telangiectasia with shunts was observed. Blood investigations ruled out metabolic, infectious, haematological, and autoimmune causes. Carotid Doppler showed no stenosis, and CT angiography of the brain did not show any vascular abnormalities. In view that no cause was identified, a diagnosis of Eales' disease with secondary Coats'-like reaction was made. Treatment consisted of FFA-guided laser photocoagulation to the areas of non-perfusion. Intavitreal anti-vascular endothelial growth factor injection was not done in view of poor visual prognosis. The condition and visual acuity remained stable during 18 months of follow-up.

This report highlights an atypical case of Eales' disease with co-existing, secondary Coats'-like reaction.