Updated 10/08/2008 from Archives of Ophthalmology Yanuzzi et al. April 2006
This was classified into 2 groups:
1) Aneurysmal telangiectasis
These are most commonly unilateral and found in men, their mean age of onset being 57. Capillary dilations/aneurysms are found in the perimacular area, but also in the midperipheral fundus and even in the anterior retina. This may therefore be a subset of Coats disease. Only leakage is seen with lipid deposition; no neovascularisation or fibrotic scarring is observed. OCT shows foveal cysts, macular oedema and shallow macular detachments.
2) Perifoveal telangiectastis
This is usually bilateral and found in men and women – average age at presentation being 59. A proliferation of retinal capillaries from the deep retinal circulation is found. The mechanism may be similar to that observed in RAP (retinal angiomatous proliferation) except that the RPE function is normal in these cases and a retino-choroidal anastomosis does not develop since the subretinal neovascular membrane does not originate from the choroid in perifoveal telangiectasis. Ischaemia or inflammation are not involved in the pathogenesis. Perifoveal telangiectasis is classified into 2 stages i) nonproliferative stage with exudation and foveal atrophy. OCT demonstrates inner retinal cysts which leads to the foveal atrophy and ii) proliferative stage with the development of a SRN and fibrosis. Pigment plaques and cyrstalline deposits may be observed variably in both stages.