Efficacy of Selective Laser Trabeculoplasty for Poorly Controlled Chronic Primary Angle Closure Glaucoma Following Iridotomy and Primary Open Angle Glaucoma

Abstract

Purpose: : To evaluate the response to selective laser trabeculoplasty (SLT) in patients with poorly controlled chronic primary angle closure glaucoma (CPACG) following iridotomy or primary open angle glaucoma (POAG) while ocular drug therapy was held constant.

Methods: : A retrospective chart review was performed to evaluate the effect of SLT on intraocular pressure (IOP) in patients with either CPACG following laser iridotomy or POAG while receiving fixed ocular drug therapy. SLT was performed to augment IOP control in patients not achieving target IOP despite medical therapy. For each patient, the first eye receiving SLT was included for analysis. Baseline IOP was defined as the average IOP on 3 separate visits on fixed ocular drug therapy prior to SLT treatment. For each patient, drug therapy was held constant throughout the study period. Gonioscopy demonstrated at least 270⁰ trabecular meshwork accessible for SLT. A total of 79 of 111 eyes met inclusion criteria and were followed for up to 18 months with a minimum of 3 post-treatment IOP measurements. Eyes with POAG received SLT 360⁰ where as eyes with CPACG received at least SLT 270⁰ by one of two glaucoma specialists at a single institution using a standardized method.

Results: : Study demographics include 53 patients with POAG and 26 patients with CPACG after iridotomy; 47 Whites, 31 African Americans, 1 Hispanic; 56 phakic and 23 psuedophakic patients. The average age was 69.8 years (SD = 10.6) and 57% were male. The average pre-treatment IOP was 17.64 mm Hg (SD = 2.74; 95% confidence interval of 17.03 to 18.25), and the average post-treatment IOP was 14.31 mm Hg (SD = 2.98; 95% confidence interval of 13.64 to 14.98). SLT produced a significant decrease in IOP of 18.83% (p < 0.0001). SLT produced a decrease of 20.06% in patients with POAG and 16.91% in patients with CPACG. Analysis of variance demonstrated that neither the type of glaucoma, age, race, gender nor phakic status influenced the response to SLT. Patients tolerated the procedure well and did not experience significant post - SLT complications. Over the 18 month post - SLT follow-up, 4 eyes required a change in ocular medication and 2 eyes required incisional glaucoma surgery to achieve target range IOP.

Conclusions: : SLT is a safe and useful adjunctive therapy in lowering IOP in patients with either POAG or CPACG after iridotomy who are not achieving target IOP with ocular drug therapy.

Keywords: laser • intraocular pressure • outflow: trabecular meshwork