Hemorrhagic retinal macrocysts in advanced Coats disease

The authors report a case of advanced unilateral Coats disease with associated hemorrhagic retinal macrocysts. Fluorescein angiography showed the macrocysts to be intensely hypofluorescent due to absence of perfused retinal blood vessels in the inner wall and presence of intracavitary blood blocking outer wall and choroidal fluorescence. Around the cystic lesions and in other areas of the peripheral retina, characteristic telangiectatic retinal blood vessels were evident. The mechanism responsible for the development of hemorrhagic retinal macrocysts in Coats disease appears to be coalescence of microcystic spaces in edematous and degenerated chronically detached retina.