Intraocular Pressure Response in the Untreated Contralateral Eye After Selective Laser Trabeculoplasty

Aim: To examine the impact of selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) in the untreated contralateral eye within 12 months after the procedure. Methods: A retrospective chart review was conducted on patients with primary open-angle, normal-tension, pigmentary, or pseudoexfoliation glaucoma who received 360-degree SLT at George Washington University. Exclusion criteria included prior or subsequent laser or glaucoma surgery within 12 months of SLT, other glaucoma types, or corticosteroid use during follow-up. Primary outcomes were IOP and medication reduction, and SLT success, defined as reducing IOP by ≥20% without additional IOP-lowering procedures or medications. Follow-up occurred at six weeks, six months, and 12 months. Demographic and clinical data were analyzed using ANOVA, paired t-tests, and chi-squared tests. Results: A total of 125 patients were included, representing a range of backgrounds: African American (57.6%), Caucasian (31.2%), Asian (5.6%), and Hispanic/Latino (4%), and 1.6% did not report their background. Significant reductions in mean IOP and medication numbers were observed in the contralateral eye at six weeks and six months (p<0.05) but not at 12 months. The contralateral eye success rates were 24% at six weeks and six months and 20.8% at 12 months. The contralateral eye was more likely to achieve success if the ipsilateral eye was successful at six weeks (odds ratio (95% confidence interval): 5.05 (1.89-13.48)), six months (16.1 (4.56-57.17)), and 12 months (5.94 (2.07-17.04)) (p<0.001 for all). Conclusion: First-time SLT results in statistically significant IOP and medication reductions in the contralateral eye at six weeks and six months. The contralateral eye was 5.05-16.1 times more likely to achieve success if the ipsilateral eye was successful within 12 months.