Idiopathic macular telangiectasia type 2 (idiopathic juxtafoveolar retinal telangiectasis type 2A, Mac Tel 2)

Macular telangiectasia type 2-also known as idiopathic perifoveal telangiectasia and juxtafoveolar retinal telangiectasis type 2A or Mac Tel 2-is an acquired bilateral neurodegenerative macular disease that usually manifests itself during the fourth to sixth decades of life and is characterized by minimal dilatation of the parafoveal capillaries with graying of the retinal area involved, a lack of lipid exudation, right-angled retinal venules, refractile deposits in the superficial retina, hyperplasia of the retinal pigment epithelium, foveal atrophy, and subretinal neovascularization (SRNV). Optical coherence tomography images typically demonstrate intraretinal hyporeflective spaces that are usually not related to retinal thickening or fluorescein leakage. The typical fluorescein angiographic finding is a deep intraretinal hyperfluorescent leakage in the temporal parafoveal area. With time the leakage may involve the whole parafovea, but does not extend to the center of the fovea. Long-term prognosis for central vision is variable and depends on the development of SRNV or macular atrophy. Pathogenesis remains unclear, but Müller cells and macular pigment appear to play a central role. Currently there is no known treatment for the underlying cause of this condition, but treatment of the SRNV may be beneficial.