Effect of apraclonidine hydrochloride on acute introacular pressure rise after argon laser iridotomy

To determine the effect of apraclonidine hydrochloride on the acute intraocular pressure (IOP) rise after argon laser iridotomy (ALI), a double-masked comparative study was carried out. Twenty-nine eyes (20 patients) with angle-closure glaucoma underwent ALI. Eighteen eyes were treated with apraclonidine, and the remainder received a placebo 1 hour before and immediately after ALI. The mean IOP increase in the apraclonidine group was lower than that in the placebo group at each postlaser interval (p less than 0.01). Although the average value of the maximal increases of IOP after ALI in the apraclonidine group was 4 mmHg, that in the placebo group was 16 mmHg. In the placebo group, 27.3% (3 out of 11 eyes) experienced an IOP rise greater than or equal to 10 mmHg. However, that kind of IOP rise was not found in the apraclonidine group (0 out of 18 eyes) (p less than 0.01). Ocular or systemic side effects were not found in a series of examinations in both groups. Therefore, apraclonidine proved to be effective in lowering the IOP rise after ALI.