Unilateral Retinal Telangiectasia with Peripheral Vascular Sheathing: A Case Report

Abstract Background Idiopathic retinal telangiectasia refers to ectatic changes in retinal blood vessels without identifiable causes. This includes a range of diseases such as Coats’ disease, Leber’s miliary aneurysms, and macular telangiectasia. Visual acuity can be severely affected when there is severe exudation or if the macula is involved. However, retinal telangiectasia can also be a sequelae to a primary ocular or systemic disorder, also known as ‘’Coats’-like reaction”. As a result, clinical presentations can overlap, making diagnosis a challenge. We present a case of unilateral retinal telangiectasia in a young adult male with atypical features of peripheral vascular sheathing and distal non-perfusion in the absence of clinically visible exudation and discuss its diagnostic challenges. Methods Case report. Results 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 tomograph of the macula revealed disorganization and thinning of the inner retinal layers with minimal intraretinal fluid. Fundus fluorescein angiography showed leakage from the aneurysms, extensive peripheral capillary fallout and enlarged foveolar avascular zone. Blood investigations ruled out metabolic, infective, hematological and autoimmune causes. Carotid Doppler showed no stenosis and CT angiography of the brain did not show any vascular abnormalities. In view that no causes was identified, a diagnosis of idiopathic peripheral telangiectasia, possibly stage 1 Coats’ disease, was made. Treatment consisted of FFA-guided laser photocoagulation to the areas of non-perfusion. Intavitreal anti-vascular endothelial growth factor was not done in view of poor visual prognosis. The condition and visual acuity remained stable during 18 months of follow-up. Conclusion This case highlights the overlapping spectrum of retinal telangiectasia and its diagnostic challenges. Although stage 1 Coats’ disease could be a possibility, some features were atypical for this diagnosis. An inflammatory vasculitis with a secondary “Coats-like reaction” is postulated, but the exact etiology is still unknown.