Background and objectives: To report the effect of laser peripheral iridotomy on the angles of eyes with chronic angle closure glaucoma.
Patients and methods: The hospital records of 171 consecutive patients with chronic primary angle closure glaucoma (CPACG) seen between October 1994 and March 1997 were analyzed to study the gonioscopic outcome of laser peripheral iridotomy (LPI). Success was defined as open angles (with or without medications for intraocular pressure (IOP) control) following LPI at the 1 month follow-up.
Results: Forty-seven eyes of 34 patients had chronic appositional angle closure glaucoma (CAACG), and 186 eyes of 124 patients had chronic synechial angle closure glaucoma (CSACG). Seventy eyes of 57 patients that underwent primary trabeculectomy for advanced disease were excluded from the study. Two hundred thirty-three eyes of 158 patients underwent LPI; the angles could be opened in 171 eyes (73.4%; confidence interval 67.7% to 79.1%) of 117 patients. Medications to control the IOP were required in 25 eyes (10.7%) of 19 patients. Fifty-four eyes of 34 patients that did not respond to LPI underwent argon laser gonioplasty. Gonioplasty was successful in opening at least 180 degrees of the angle in all eyes. There was no significant difference in success between CAACG (74.5%) and CSACG (73.1%). Age, IOP, and field loss were not predictors of outcome. There was perfect concordance of results between the 2 eyes of patients who had bilateral LPI.
Conclusions: In this series, laser iridotomy was successful in opening the angle in 73.4% of eyes. Gonioplasty opened the angle in all eyes that underwent this procedure. The effect of iridotomy on one eye was predictive of the effect on the fellow eye.