Evaluation of tube extender use in glaucoma management: insights from a cohort study

To describe the clinical indications for tube revision with a Tube Extender and to characterize the eyes in which they were used. Single-center retrospective cohort of eyes undergoing Tube Extender implantation (2015–2023). Clinical data were collected from medical records, and Fisher’s exact test assessed associations between glaucoma type and revision indication. Twenty-two eyes from 22 patients were included. The mean age at tube revision was 53 years, and 68% of patients were male. The most common glaucoma types were primary open-angle glaucoma (36%), uveitic glaucoma (23%), and neovascular glaucoma (18%). Tube Extenders were most frequently used with Ahmed devices (59%), followed by Baerveldt devices (28%). The mean interval from the original aqueous shunt surgery to Tube Extender implantation was 764 days, with a median of 497 days (IQR 100–582). Eighteen tube revisions were performed for a single indication, while four were performed for two or more indications. The main reasons for implantation were tube retraction (41%), corneal touch (27%), tube exposure (23%), and tube obstruction (13%). The tube was most commonly repositioned back into the anterior chamber (64%), followed by repositioning from the anterior chamber to the sulcus (27%) and repositioning within the sulcus (9%). Out of the 22 tube revisions, two were combined with cataract surgery and one with corneal transplantation. There was no statistically significant association between glaucoma type and indication for tube revision. Tube Extenders were primarily used to address complications such as tube retraction, corneal issues associated with glaucoma drainage devices, tube exposure, and obstruction. They offer a practical surgical solution to salvage existing aqueous shunt implants without the need for full device replacement, but additional studies are needed to assess long-term outcomes.