Peripheral anterior synechiae formation after trabeculoplasty

Argon laser trabeculoplasty (ALT) was performed on 60 eyes with primary open angle glaucoma and 59 eyes with capsular (pseudoexfoliation) glaucoma. Laser applications of four different power levels (500, 600, 700, and 800 mW) were directed either at the anterior trabecular meshwork or at the posterior trabecular meshwork. Gonioscopic examination to reveal peripheral anterior synechiae (PAS) formation was performed before and six months after ALT. Peripheral anterior synechiae were found in 26 (22%) of the eyes. With 500-mW laser power and anterior trabecular meshwork burns, no PAS developed. With 800-mW posterior trabecular meshwork burns, PAS developed in 12 (40%) of the eyes. No correlation between PAS formation and sex, age, glaucoma type, preoperative antiglaucoma medication, pigmentation of the chamber angle, and visible burn effect was found. Intraocular pressure decrease after ALT was significantly smaller in eyes with PAS.