In early stages it is characterised by large areas of intra and subretinal yellowish exudates and haemorrhages associated with overlying dilated and touous retinal blood vessels and a number of small aneurysms near the posterior pole and around the disc. It may present with visual loss, strabismus or leukocoria (whitish pupillary reflex) and thus needs to be differentiated from retinoblastoma. The condition usually progresses to produce exudative retinal detachment and a retrolental mass. In late stages complicated cataract, uveitis and secondary glaucoma occur, which eventually end in phthisis bulbi. Treatment Photocoagulation or cryotherapy may check progression of the disease if applied in the early stage. However, once the retina is detached the treatment becomes increasingly difficult and success rate declines to 33 percent. Ref:comprehensive ophthalamology A k khurana 4/E pageno:266 Coats' disease is a severe form of retinal telengiectasia(idiopathic congenital vascular malformation), which typically affects one eye of boys in their first decade of life.