For up to one year, 22 patients with ocular hypertension or glaucoma wore a seven-day sustained release device (Ocusert) containing pilocarpine with acceptable retention and no important side-effects. Comparison of prestudy medical regimens using eye drops with those defined as minimum controlling concentrations indicated a high rate of overmedication. The hypotensive effect of two Ocusert strengths was compared to four pilocarpine drop concentrations. Concurrent administration of epinephrine drops did not interfere with Ocusert action and had the anticipated additive effect. Further study indicated the need for continuous wearing and delimited the effective duration of action for single Ocuserts to seven days.