One hundred twenty-nine patients thought to be at risk for developing angle-closure glaucoma underwent a baseline examination, which included gonioscopy, refraction, anterior chamber pachymetry, ultrasound biometry, and an angle-closure provocative test. Patients were then followed up with no treatment. Mean follow-up was 2.7 years with a range up to six years. Twenty- five patients developed angle closure in at least one eye during the follow- up period, but in most (17 of the 25 patients), the angle closure was non- acute (that is, no clinical signs or symptoms and no increase in intraocular pressure). None of the test factors studied showed a high sensitivity or positive predictive accuracy in detecting the eyes that later developed angle closure.