To compare the central corneal thickness measurement in patients with exfoliation, primary open-angle glaucoma, ocular hypertension and normal controls and to evaluate the value of corneal thickness in the diagnosis and management of glaucoma. Prospective study in progress. Randomly selected patients undergo a comprehensive ophthalmic exam which includes 2 separate pachymetry measurements in 2 different examinations at the same time of the day (10:00 am) with 3 different pachymeters. The values obtained are correlated with a number of other glaucoma parameters. A thinner cornea may represent a specific attribute and an additional risk factor for patients with exfoliation. Evaluation of corneal thickness is an important exam in the management of patients with exfoliation.