Comparison of Outcomes for Laser Trabeculoplasty after Kahook Dual Blade Goniotomy Versus in Goniotomy-Naive Eyes

Introduction This was a comparison of laser trabeculoplasty (LTP) outcomes in eyes with prior Kahook Dual Blade (KDB) goniotomy versus in goniotomy-naive control eyes. Methods This was a retrospective matched comparative case series. We identified a cohort of patients undergoing LTP between February 2017 and July 2020 at University of Missouri. Patients were grouped by history of KDB goniotomy versus goniotomy-naivety as a control group. Inclusion criteria included age at least 18 years, minimum of 6 months follow-up after LTP, and minimum period of 6 months between KDB goniotomy and LTP. All KDB procedures were combined with uncomplicated phacoemulsification. Patients who had any additional intraocular pressure (IOP)-lowering procedures between KDB goniotomy and LTP were excluded. Patients in the control group received a single LTP procedure. Primary outcome consisted of the comparison of LTP success, defined as IOP reduction of at least 20% or reduction of glaucoma medications from pre-LTP baseline. Secondary outcomes included IOP and medication reduction from pre-LTP baseline. Results Twenty-one eyes of 19 patients with history of KDB goniotomy and 42 eyes of 36 control patients without previous angle or laser procedures were included. Baseline characteristics including age, gender, ethnicity, type and severity of glaucoma, baseline IOP, and baseline medications were matched between groups. The LTP success rate was higher in the control group, but was not statistically significant (64% vs 57%, p = 0.58). IOP reduction was only significant in the control eyes (2.50 +/- 4.0 mmHg, p = 0.01 vs 2.35 +/- 4.7 mmHg, p = 0.08). The number of glaucoma medications was not significantly reduced in either group. Conclusion LTP may have a limited IOP- and medication-lowering effect in eyes with a history of KDB goniotomy compared to goniotomy-naive eyes.