Abstract
Purpose :
Selective laser trabeculoplasty (SLT) and minimally invasive glaucoma surgery (MIGS) have come to the forefront of treatment paradigms for open-angle glaucoma (OAG). Studies have shown mixed results in augmenting intraocular (IOP) reduction after MIGS with SLT. The purpose of this study is to examine the safety and efficacy of SLT after implantation of a trabecular meshwork bypass microstent (iStent, Glaukos Corporation, “TMMS”) combined with phacoemulsification.
Methods :
A retrospective analysis of all eyes that underwent SLT following TMMS with phacoemulsification surgery compared to a matched cohort of pseudophakic eyes that had SLT without prior glaucoma procedures was performed. Patients were matched by age, gender, race, glaucoma type and severity, preoperative IOP within 2mmHg, and NOM within 1 NOM. Data was collected at intervals up to one year after the procedure. Failure criteria included <20% IOP reduction, the same or more number of glaucoma medications (NOM), and further glaucoma surgery. Kaplan-Meier (Km) survival analysis was implemented for a graphical comparison of relative success between both groups.
Results :
A total of 36 eyes were studied. Baseline characteristics between the study group and matched cohort were similar. Both groups received similar power SLT treatment (p=0.207). 18 eyes had SLT following TMMS and phacoemulsification with a baseline mean IOP of 17.1 ± 4.7 mm Hg on 2.2 ± 0.9 NOM. This is compared to 18 eyes in the control group with a baseline mean IOP of 18.8 ± 4.1 mm Hg on 2.1 ± 0.9 NOM. At one year, the study group had a mean IOP decrease of 10.71% ± 17.11% on 1.7 ± 1 NOM, compared to an 18.62% ± 14.37% decrease on 2.2 ± 1.3 NOM in the control group (p=.095). Fewer eyes met success criteria in the case versus the matched control group at 1 year post-SLT (45% vs. 78%, p=0.025). 2 eyes (11%) had complications (1 prolonged inflammation and 1 hyphema) that resolved medically in the case group; no controls experienced complications.
Conclusions :
SLT may be less effective at reducing IOP in eyes that have already had phacoemulsification plus TMMS. However, it may still be beneficial in reducing NOM, consistent with previous literature. Most patients met failure criteria due to the strict requirement of >20% IOP reduction in both groups, which may have been difficult to attain due to low baseline IOP.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.