Injected Ranibizumab to Treat Macular Telangiectasia Without New Blood Vessel Formation

Overview

This study will examine whether the drug ranibizumab is an effective treatment for macular telangiectasia, a condition in which existing blood vessels near the macula (the back part of the eye responsible for sharp central vision) become dilated and twisted, and new abnormal blood vessels may form under the retina. Both the existing dilated vessels, as well the new subretinal vessels can leak fluid and blood, distort the retina, and affect vision. This study will see if ranibizumab can slow or stop the leakage and growth of existing, dilated, macular vessels in cases where new vessel formation under the retina is absent. Patients 18 years of age and older who have macular telangiectasia without new blood vessel formation may be eligible for this study. Visual acuity must be 20/40 or worse. Participants receive at least four injections of ranibizumab into the eye over a 12-week period. After the fourth injection, additional injections may be given every 4 weeks for up to 1 year if the doctor determines that they may be of benefit. In addition to ranibizumab treatment, patients undergo the following procedures: * Medical history and physical examination. * Eye examination, including dilation of the pupils and measurement of the fluid pressure in the eye. * Fluorescein angiogram: A yellow dye is injected into an arm vein and travels to the blood vessels in the eyes. Photographs of the retina are taken with a special camera that flashes a blue light into the eye. The photos show whether any dye has leaked from the vessels into the retina. * Indocyanine green angiography: This procedure identifies feeder vessels that may be supplying the abnormal blood vessels. The test is similar to fluorescein angiography, but uses a green dye and flashes an invisible light. * Autofluorescence imaging: This test examines how well the retina functions. The back of the eye is photographed with a bright light. * Optical coherence tomography: This test measures retinal thickness. A light shined into the eye produces cross-sectional pictures of the retina. The measurements are repeated during the study to determine if retinal thickening is getting better or worse, or staying the same. * Stereoscopic color fundus photography: The pupils are dilated and special photographs of the inside of the eye are taken to evaluate the retina and measure changes that occur over time. The camera flashes a bright light into the eye for each picture. * Follow-up visits: The doctor evaluates the effects of the study treatment before and after each injection. Patients are contacted by phone 3 days after each injection to check on any treatment side effects. A final follow-up visit is scheduled 8 weeks after the last treatment.

Retinal telangiectasis is a group of rare, idiopathic retinal vascular anomalies affecting the retinal capillaries in which irregular capillary dilation and incompetence occur in the macula. This is the former group 2 in the Gass classification of idiopathic juxtafoveal telangiectasia in which fluorescein angiography showed leakage with capillary dilation. These patients typically are diagnosed in their fifth or sixth decade of life. Both sexes may be affected. Minimal exudation, superficial retinal crystalline deposits, and right-angle venules characterize this disorder. As the disease progresses, intraretinal pigment plaques and eventually subretinal/choroidal neovascularization develop. Currently, these patients will be classified as macular telangiectasia. The pathogenesis of the disease is unknown. Because of the leakage of the retinal vessels and also the finding of neovascularization, it is possible that vascular endothelial growth factor (VEGF) may be implicated in this disease. The purpose of this study is to evaluate the possible role of ranibizumab for the treatment of five participants with macular telangiectasia with hyperfluorescence on fluorescein angiography, with vision decreased to 20/40 or worse, without neovascularization. The primary outcome will be a visual acuity change, either increase or decrease of 15 letters or more at one year. The secondary outcomes measured at one year will include visual acuity changes of 10 letters or more, the change in retinal thickening documented by OCT, the extent and degree of fluorescein leakage, the change in area of hypofluorescence, and the change in central retinal sensitivity. This is a pilot study designed to evaluate the feasibility and potential efficacy of treating patients with macular telangiectasia in a larger, phase III study within the organization of the MAC TEL Research Group, sponsored by the Lowy Foundation. Currently, the research group is enrolling 200 patients affected with this condition for a natural history study in 22 international clinical centers.