We reviewed the records of 324 patients (395 eyes) seen between 1973 and 1987 with a diagnosis of idiopathic premacular gliosis. Mean age of onset was 64.6 years, 189 (58.3%) were women, and all but six patients were white. Initial visual acuity was 20/40 or better in 214 eyes (54.2%), 20/50 to 20/100 in 136 eyes (34.4%), and poorer than 20/100 in 45 eyes (11.4%). Follow-up examinations were made in 214 eyes. After a mean follow-up period of 33.6 months, 106 (49.5%) of the 214 eyes maintained a visual acuity within one line of initial visual acuity, 28 (13.1%) were more than one line better, and 80 (37.4%) were poorer. Partial or complete posterior vitreous detachment was present in 303 (84.9%) of the 357 eyes undergoing vitreous study; 43 (14.2%) of these 303 eyes had partial vitreous detachment with vitreous adhesion to the macula. Cystoid macular edema was present on angiography in 77 (20.6%) of 373 eyes undergoing fluorescein angiography; 20 (26.0%) of these 77 eyes had partial posterior vitreous detachment with vitreous adhesion to the macula, whereas only 23 (7.8%) of the 296 eyes without cystoid macular edema had such vitreous adhesion (P less than .001). Other findings were myopia in 116 of 367 eyes (31.6%) (103, or 88.8%, of the myopic eyes had posterior vitreous detachment), and increased intraocular pressure in 56 of 324 eyes (17.3%).