Incidence, etiology, and risk factors for tube explantation in patients undergoing patch-free glaucoma drainage device.

Objective: To report the incidence, etiology, and risk factors for tube explantation in patients undergoing patch-free glaucoma drainage device (GDD).

Methods: Of the total 1303 patients who underwent patch-free GDD (703 non-valved GDD and 600 valved GDD) for refractory glaucoma during January 2020-October 2023, we identified five cases of postoperative complications following GDD that required tube or shunt removal.

Results: Median (IQR) age of our study cohorts was 54.5 (8-66) years. The incidence of tube exposure and tube explantation was 0.003% and 0.004%, respectively. The median time interval for tube or plate explantation from the time of GDD surgery was 11.5 (2-16) months. The diagnoses of refractory glaucoma for which GDD was performed were secondary glaucoma following multiple vitreoretinal (VR) surgery (60%), primary open-angle glaucoma (20%), and aphakic glaucoma (20%). Of these, two patients (40%) presented with recurrent tube exposures, two patients (40%) with tube exposure and early endophthalmitis, and one patient (20%) with persistent hypotony. Four patients (80%) had undergone non-valved Aurolab aqueous drainage implant and one underwent (20%) Ahmed glaucoma implant. Three patients (60%) had diabetes mellitus with a history of multiple VR surgical intervention. GDD explantation was done in three patients (60%), and the remaining two patients (40%) required only tube amputation. One patient presented with orbital cellulitis, and there was no culture growth seen in any of our study cohorts.

Conclusions: Tube and plate exposures pose a significant risk for potential infections and warrant prompt explantation of GDD to avoid endophthalmitis. Previous history of multiple VR surgeries, diabetes mellitus, and non-valved implants were the common risk associations noted for tube exposures in our retrospective study.