Argon Laser Trabeculoplasty. Variation of Methods and Immediate Complications

Abstract

Argon laser trabeculoplasty (ALT) was performed in 157 eyes with primary open-angle glaucoma or capsular glaucoma. Three different methods of ALT were employed to determine if the variation of methods affects the incidence of immediate intraocular pressure (IOP) rise. Thirty-six eyes received 100 burns for 360° to the posterior trabecular meshwork and were categorized as Group 1. Group 2 comprised 84 eyes given 50 burns for 180° to the posterior meshwork. Group 3 consisted of 37 eyes treated with 50 burns for 180° to the anterior trabecular meshwork. The duration of each burn was set for 0.2 sec in Group 1 and 0.1 sec in Groups 2 and 3. The power of each burn ranged from 700 to 1000 mw in each group. The immediate postlaser IOP rise was defined as the pressure elevation exceeding prelaser value by 5 mmHg or greater. In Group 1 the incidence of IOP rise was 83% and it was 60% after the first session in Group 2. In Group 3 it was only 30%. The sustained, marked pressure rise was most frequently observed in Group 1 as compared with other two groups. Other complications including sustained iritis, peripheral anterior synechiae and hyphema were most frequently seen in Group 1 and least in Group 3. The rate of successful IOP control defined as IOP less than 20 mmHg was achieved in 39% in Group 1, 68% in Group 2 and 49% in Group 3. The follow-up period ranged from 2 to 56 months.