Effectiveness of Angle-Based Minimally Invasive Glaucoma Surgery after Laser Trabeculoplasty: An Analysis of the IRIS® Registry (Intelligent Research in Sight)

Abstract

ObjectiveAngle-based minimally invasive glaucoma surgery (ab-MIGS) has grown substantially, although long-term efficacy is poorly understood. We analyze ab-MIGS effectiveness with/without preceding laser trabeculoplasty (LTP). DesignRetrospective cohort study SubjectsEyes undergoing ab-MIGS (Canaloplasty, Goniotomy, Trabectome, iStent) with/without prior SLT (<2 years preceding MIGS) were identified in the IRIS® Registry (Intelligent Research in Sight) 2013-2018. MethodsPropensity score matching (PSM) was undertaken to define 4 cohorts: (i) standalone ab-MIGS, no prior LTP vs (ii) standalone ab-MIGS, with prior LTP; and (iii) ab-MIGS + phacoemulsification, no prior LTP vs (iv) ab-MIGS + phacoemulsification, with prior LTP. Main Outcome MeasuresFailure was defined as subsequent glaucoma reoperation following ab-MIGS (either MIGS or traditional glaucoma surgery). Time to event outcome and incidence rates were calculated using survival analysis, and adjusted hazard ratios (aHR) generated using multivariate Cox proportional hazards models. Medication data was not available for analysis. Results164,965 unique MIGS procedures were performed, from 2013-2018. After PSM, we identified 954 eyes undergoing standalone ab-MIGS and 7,522 undergoing ab-MIGS + phacoemulsification.For eyes undergoing standalone ab-MIGS, those with prior LTP (n=477) were more likely to undergo reoperation vs those without LTP (n=477) at 6 and 12 months. In multivariable models, those with prior LTP were more likely to undergo reoperation over the 36-month period vs those without prior LTP (aHR 1.53 (CI 1.15-2.04), p=0.004). For eyes undergoing ab-MIGS + phacoemulsification, those with prior LTP (n=3,761) were more likely to undergo reoperation vs those without LTP (n=3,761) at 12, 24 and 36 months. In multivariable models, those with prior LTP were more likely to undergo reoperation over the 36-month period vs those without prior LTP (aHR 1.53 (CI 1.15-2.04), p=0.004). ConclusionsPrior LTP may be associated with a higher chance of subsequent glaucoma surgery following ab-MIGS, either with or without concurrent phacoemulsification. These findings have important implications in understanding who may benefit most from ab-MIGS, and guiding patient and surgeon treatment expectations.