Exact Matching of Trabectome-Mediated Ab Interno Trabeculectomy to Conventional Trabeculectomy with Mitomycin C Followed for Two Years

Abstract

AbstractPurposeWe used exact matching for a highly balanced comparison of ab interno trabeculectomy (AIT) with the trabectome to trabeculectomy with mitomycin C (TRAB).Methods5485 patients who underwent AIT were exact-matched to 196 TRAB patients by baseline intraocular pressure (IOP), number of glaucoma medications, and glaucoma type. Nearest-neighbor-matching was applied to age. Success was defined as a final IOP of less than 21 mmHg, IOP reduction of at least 20% reduction from baseline, and no secondary surgical interventions. Outcomes were measured at 1, 3, 6, 12, 18, and 24 months.Results165 AIT could be matched to 165 TRAB. The mean baseline IOP was 22.3±5.6 mmHg, and the baseline number of glaucoma medications was 2.7±1.1 in both groups. At 24 months, IOP was reduced to 15.8±5.2 mmHg in AIT and 12.4±4.7 mmHg in TRAB. IOP was lower than baseline at all visits (p<0.01) and lower in TRAB than AIT (p<0.01). Glaucoma medications were reduced to 2.1 ± 1.3 in AIT and 0.2 ± 0.8 in TRAB. Compared to baseline, patients used fewer drops postoperatively (p<0.01) and more infrequently in TRAB than in AIT (p>0.01). Secondary surgical interventions had the highest impact on success and became necessary in 15 AIT and 59 TRAB patients. Thirty-two challenging events occurred in TRAB and none in AIT.ConclusionBoth AIT and TRAB reduced IOP and medications. This reduction was more significant in TRAB but at the expense of four times as many secondary interventions.Key messagesDespite vastly different IOP reduction and safety profile, ab interno trabeculectomy with the Trabectome and trabeculectomy with mitomycin C are both used as primary glaucoma surgeries. Exact matching allowed us to strictly focus on identical IOP and medications to create highly similar patient pairs for a balanced comparison that cannot be accomplished short of a randomized controlled trial. We found that trabeculectomy could achieve low IOPs and independence from drops, but trabeculectomies often required postoperative interventions. Trabectome patients had a lesser reduction of IOP and drops but needed far fewer interventions.