Tube Versus Trabeculectomy IRIS Registry Study: 1-Year Secondary Treatment Outcomes

Purpose: To describe 1-year secondary outcomes in the Tube Versus Trabeculectomy IRIS® (Intelligent Registry In Sight) Registry Study (TVT_IRIS), and to compare to the TVT randomized controlled trial (TVT_RCT).

Design: TVT_IRIS was a retrospective cohort study.

Methods: The 2013-2017 IRIS Registry was used to identify eyes that received a tube shunt (tube) or trabeculectomy after a previous trabeculectomy and/or cataract surgery and had 1 year of follow-up. The TVT_RCT compared a Baerveldt 350-mm² glaucoma implant to trabeculectomy in similar eyes.

Results: In the TVT_IRIS cohort, the tube (n = 236, 56.3%) and trabeculectomy (n = 183, 43.7%) groups had similar and significant reductions in intraocular pressure (IOP) from baseline to 1 year. In the tube group, IOP (mean ± SD) decreased from 26.6 ± 6.5 mm Hg at baseline to 14.3 ± 4.8 mm Hg at 1 year. In the trabeculectomy group, IOP decreased from 25.3 ± 6.4 mm Hg at baseline to 13.5 ± 5.2 mm Hg at 1 year. The trabeculectomy groups from both studies had similar 1-year IOP reduction (P = .18), although the TVT_RCT cohort used fewer medications at all time points (P < .01). There were more pronounced differences in the mean IOP and medications between the tube groups in the 2 studies, presumably due to the inclusion of valved tubes in TVT_IRIS. More reoperations occurred in TVT_IRIS.

Conclusions: The TVT_IRIS tube and trabeculectomy groups had comparable 1-year IOP reduction, although trabeculectomy eyes used fewer glaucoma medications. The trabeculectomy group in TVT_IRIS and TVT_RCT had similar IOP and medication reduction at 1 year. Randomized controlled trials and electronic health record data both provide invaluable insight into surgical outcomes.