Investigators conducted a retrospective analysis of Medicare claims data to evaluate the economic and reintervention burdens of incisional glaucoma surgery failures.
Study design
Patients with primary open-angle glaucoma (POAG) treated with incisional glaucoma surgery (trabeculectomy, tube shunt, or EX-PRESS shunt) from 2010 through 2011 were identified in the Medicare 5% Standard Analytical Files (N = 1945). Claims data from 2005 to 2016 for each patient were evaluated for prior incisional surgeries and downstream procedures in the treated eye within 5 years of index.
Outcomes
Rates of failure, glaucoma reoperations, or nonfailure complications rose over 5 years after index for all patient subgroups. At 1 year, 15.1% of EX-PRESS shunt patients, 11.6% of tube shunt patients, and 8.8% of trabeculectomy patients had experienced failure based on post-index procedures; after 5 years of follow-up, these rates had increased to 31.5%, 27.1%, and 23.5%, respectively. Five-year rates of glaucoma reoperations ranged from 14.0% to 18.3%. Among tube shunt and trabeculectomy patients with prior incisional surgery, the 5-year failure rates were 32.5% and 32.6%, respectively, and reoperation rates were 12.0% and 26.1%, respectively.
Limitations
This study may have underestimated failure rates because patients who did not undergo further incisional glaucoma surgery after index may still have had inadequate IOP control. This study also did not identify patients whose IOP results or medications use may indicate failure of the index surgery if they did not undergo additional surgery. Downstream procedures within 90 days of the index surgery that do not require a return to the operating room (e.g., bleb needling) are not paid under Medicare fee-for-service terms, so short-term complications and interventions are likely underrepresented in the data.
Clinical significance
In a real-world setting, roughly 20% of trabeculectomy or tube surgeries for POAG had failed by 5 years following surgery. This information will be useful to physicians when discussing treatment options with patients and setting realistic expectations. Costs of the procedures over time are similar, with a slight advantage to trabeculectomy.