Burden of Trabeculectomy and Glaucoma Drainage Implantation after Laser Trabeculoplasty: A Two-Year Follow-up Study

Purpose: To evaluate the burden of incisional glaucoma surgery (trabeculectomy and glaucoma drainage device implantation) after laser trabeculoplasty (LTP) in the United States. Design: Retrospective, matched, case-comparison study. Participants: Medicare beneficiaries who underwent LTP between January 2012 and December 2014 were identified using the 5% Medicare Current Beneficiary Survey. Methods: Subjects aged 35 years or older at the time of LTP with ocular hypertension, suspected glaucoma, or mild open-angle glaucoma (OAG) were matched to a comparison group without LTP on the basis of age, gender, race, geographic region, and glaucoma diagnosis codes. Survival analysis and Cox proportional hazard analysis were performed. Main Outcome Measures: Primary analysis included risk of incisional glaucoma surgery. Secondary analysis included risk of conversion to moderate or severe OAG based on billing data. Results: The mean age of study participants was 75.0 ± 8.9 years. After 2 years, 40 of 2435 eyes required incisional glaucoma surgery after LTP, and 51 of 2435 eyes required glaucoma surgery in the comparison group (P = 0.27, adjusted for covariates). Regardless of intervention, Black Americans were more likely to require glaucoma surgery (hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.13–3.17). Patients with a diagnosis of OAG were more likely to require surgery than glaucoma suspects (HR, 2.03; 95% CI, 1.12–3.69). Black Americans were also more likely to require surgery or convert to more severe glaucoma (HR, 3.21; 95% CI, 1.92–5.37) versus White Americans. Conclusions: Laser trabeculoplasty did not alter the need for subsequent incisional glaucoma surgery among glaucoma suspects or patients with mild OAG. Regardless of treatment with LTP, African heritage and OAG diagnosis status were risk factors for requiring glaucoma surgery.