Purpose: The purpose of this report is to review the clinical variations and natural course of Coats disease, using strict diagnostic guidelines.
Methods: In a retrospective, consecutive series, Coats disease was defined as idiopathic retinal telangiectasia with intraretinal or subretinal exudation without appreciable signs of retinal or vitreal traction. We reviewed our experience with the clinical features, complications, and diagnostic approaches to Coats disease.
Results: In 150 consecutive patients (158 eyes), Coats disease was diagnosed at a median age of 5 years (range, 1 month to 63 years), occurred in 114 males (76%), and was unilateral in 142 patients (95%). There was no predilection for race or laterality. The most common referral diagnoses were Coats disease in 64 cases (41%) and retinoblastoma in 43 (27%). The first symptom or sign was decreased visual acuity in 68 cases (34%), strabismus in 37 (23%), leukocoria in 31 (20%), and 13 patients (8%) were asymptomatic. Visual acuity at presentation was 20/200 to no light perception in 121 eyes (76%). The anterior segment was normal in 142 eyes (90%). The retinal telangiectasia involved the midperipheral or peripheral fundus in 156 of the 158 eyes (99%) and was restricted to the macular area in two eyes (1%); involved mainly the temporal fundus in 66 eyes (42%), inferior fundus in 41 eyes (26%), and more than one sector in 34 eyes (22%). Retinal exudation was present in all 12 clock hours in 86 eyes (55%) and six or more clock hours in 115 eyes (73%). There was a total retinal detachment in 74 eyes (47%) and neovascular glaucoma in 12 (8%). Retinal macrocysts were present in 18 eyes (11%), a vasoproliferative tumor in nine eyes (6%) and retinal neovascularization in four eyes (3%). Fluorescein angiography in 49 of the 158 eyes (37%) disclosed early hyperfluorescence of the telangiectasias and macular edema in 18 of eyes (37%). Ultrasonography typically showed a retinal detachment but no solid mass.
Conclusions: Coats disease is a distinct clinical entity characterized by idiopathic retinal telangiectasia and retinal exudation. It is usually unilateral, occurs mostly in young males, and can cause severe visual loss resulting from exudative retinal detachment. The clinician should follow strict criteria in making the diagnosis, to avoid confusing Coats disease with other forms of exudative retinopathy.