Glaucoma after cataract extraction occurs more frequently following operative and postoperative complications.1,2Thus, the presence of retained lens material, a flat anterior chamber, iridocyclitis, or vitreous loss results in an increased incidence of peripheral anterior synechiae and glaucoma. Rupture of the lens capsule appears to be the complication which leads to glaucoma most frequently. It was the purpose of the present study to attempt to evaluate the effects of cataract extraction and its complications on the outflow channels. It was thought that pre- and postoperative tonography and gonioscopy might offer an approach whereby more subtle changes in aqueous outflow could be detected even in the absence of overt glaucoma. Methods A group of 111 patients were subjected to repeated tonography and gonioscopy before and after cataract surgery. These persons had a total of 139 cataract extractions performed by house officers of the Washington University Clinic Service between Sept. 8,