This study was part of a larger project, the EDCCS, designed to identify potential risk factors associated with the following retinal diseases: branch retinal vein occlusion, central retinal vein occlusion, neovascular age-related macular degeneration, rhegmatogenous retinal detachment, and idiopathic macular hole. The study, supported by the National Eye Institute, Bethesda, Md, was conducted at the following 5 clinical centers: University of Illinois at Chicago; the Medical College of Wisconsin, Milwaukee; the Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston; the Manhattan Eye, Ear, and Throat Hospital, New York, NY; and the Johns Hopkins Wilmer Eye Institute, Baltimore, Md. The centers enrolled patients with (the cases) and without (controls) the various retinal diseases from May 1, 1986, to December 31, 1990. We invited the 198 patients with idiopathic macular hole for a follow-up examination that was conducted from November 17, 1992, to July 30, 1994, at each of the clinical centers. Approvals from the institutional review board for human subject research were obtained at each of the clinical centers for baseline and follow-up studies.