We conducted a retrospective study of 45 eyes of 45 patients with chronic open-angle glaucoma to evaluate the rate of progression of scotomas. "Scotoma mass" was calculated and regressed on time to obtain the rate of visual field change. Twenty-two eyes (49%) showed a linear type of progression, nine (20%) showed a curvilinear progression, three (7%) showed episodic progression, and 11 (24%) showed no significant progression. The mean scotoma mass was significantly lower in the curvilinear group than in the linear group.