Retrolental white mass.

From 1985 till 1990 twenty-three children aged seven weeks to six years presented with a retrolental white mass. Six children had retinoblastoma, six Coats' disease, five retinopathy of prematurity, four persistent hyperplastic primary vitreous, one cysticercosis and one retinal detachment. Retinoblastoma and Coats' disease was only seen in children over eight months, whereas persistent hyperplastic primary vitreous and retinopathy of prematurity all presented before the age of six months. Differentiation between Coats' disease and retinoblastoma is not always easy. Most helpful for the diagnosis is to perform funduscopy under general anaesthesia with special attention to the vasculature. Ultrasounds are helpful, but can give confusing results. Cytological analysis of subretinal fluid is useful in Coats' disease.