This study is an open-label, pilot study of intravitreal injections of ranibizumab in participants with macular telangiectasia. Genentech will supply the ranibizumab for this trial. Five study participants, without neovascularization, will be selected for this study. The study eye in participants who present with bilateral macular telangiectasia will be designated as the eye with the greater severity of involvement as determined by visual acuity measurements, fluorescein angiography and OCT results. However, in the case where the more severely affected eye is judged to unlikely benefit from treatment due to irreversible structural changes (extensive atrophy and pigmentary change, chronic macular scarring), then the less severely affected eye may be considered. . In cases where both eyes are equivalent, the investigator and participant will determine the study eye. The fellow eye will be treated according to standard-of-care. Because the pathogenesis of this condition is unknown, one can only speculate on the possible role of vascular endothelial growth factor (VEGF) in this condition. The leakage seen on fluorescein angiogram reflects on the endothelial dysfunction of the retinal vessels although it is not certain that this may be a primary or a secondary condition. The fluorescein leakage of macular telangiectasia resembles that of diabetic retinopathy where VEGF has proven to be important in its pathogenesis. For these reasons, we believe it is important to test the possible role of anti-VEGF therapy with intravitreal injections of ranibizumab. We will learn about the feasibility of this treatment while we learn about any safety issues. We do not understand fully the cause of vision loss in the early stages of the disease. The results of the study showed that there was no improvement in visual function with mild decrease in the retinal leakage from the fluorescein. This treatment is not to be recommended for what may be a neurodegenerative disease.

National Institute of Health (NIH)
National Eye Institute (NEI)
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U.S. National Eye Institute
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Charbel Issa, Peter; Gillies, Mark C; Chew, Emily Y et al. (2013) Macular telangiectasia type 2. Prog Retin Eye Res 34:49-77
Meleth, Annal D; Toy, Brian C; Nigam, Divya et al. (2013) Prevalence and progression of pigment clumping associated with idiopathic macular telangiectasia type 2. Retina 33:762-70
Chew, Emily Y (2012) How prevalent is macular telangiectasia type 2? Ophthalmic Epidemiol 19:183-4
Toy, Brian C; Koo, Euna; Cukras, Catherine et al. (2012) Treatment of nonneovascular idiopathic macular telangiectasia type 2 with intravitreal ranibizumab: results of a phase II clinical trial. Retina 32:996-1006