Risk Factors Associated with Tube Shunt Erosion at a Tertiary Eye Center

Abstract

Purpose : Tube shunt erosion is a serious potential long-term complication that can occur after insertion of tube shunts for intraocular pressure control. Tube erosions are associated with endophthalmitis and thus poor outcomes. The purpose of this retrospective cohort study was to identify risk factors associated with tube shunt erosion at the Bascom Palmer Eye Institute (BPEI).

Methods : We conducted a review of all tube shunt implantation and revision surgeries at BPEI between May 10, 2014 & September 10, 2020. Tube shunt insertions were identified by Current Procedural Terminology codes 66180 & 66179, while revisions were identified by codes 66184 & 66185. Demographic, clinical, and surgical data were collected. Eyes that developed tube erosions were compared to those that did not to identify risk factors for erosion. Univariable & multivariable analyses as well as Kaplan-Meier survival analysis were completed.

Results : A total of 1,981 tube shunt insertion and revision surgeries were analyzed, of which 111 erosions were identified. Among those tubes inserted at BPEI, the erosion rate was 2.5%. Risk factors associated with tube shunt erosion included older age (69.3±12.7 vs. 63.7±18.3 years, p<0.001), greater number of intraocular surgeries prior to tube shunt placement (2.4±1.7 vs. 1.3±1.3, p<0.001), a history of scleral buckle surgery (erosion in 12.0% vs. 2.4% of eyes with scleral buckle vs. no scleral buckle respectively, p=0.0237), second tube shunt (erosion in 12.3% vs. 4.2% among first tubes respectively, p<0.0001), and tube shunt placement in the superonasal & inferonasal quadrants compared to superotemporal quadrant (erosion in 50.0%, 8.5%, & 4.6% respectively, p<0.0001). Notably, the type of patch graft material was not a risk factor for tube erosion. Second & third tube shunts (p<0.0001) and superonasal & inferotemporal placement (p<0.0001) were associated with faster erosion. Mean follow-up time from tube shunt insertion to last visit was 14.8±20.1 months among erosion eyes, compared to 32.4±24.6 months for those without erosion.

Conclusions : Risk factors associated with tube shunt erosion included older age, greater number of surgeries prior to tube shunt placement, history of prior scleral buckle, second tube shunt, and location other than the superotemporal quadrant. Identifying the rate and risk factors for tube shunt erosion is essential for patient counseling, patient selection, and surgical planning.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.