Baerveldt surgery outcomes: anterior chamber insertion versus vitreous cavity insertion

We compared the outcomes of Baerveldt glaucoma implant (BGI) surgery between vitreous cavity and anterior chamber insertion.

We retrospectively analyzed a total of 105 consecutive eyes that underwent BGI surgery and were followed up for ≥ 12 months. BGI surgery was performed via the anterior chamber (AC group 48 eyes) or the pars plana into the vitreous cavity (VC group 57 eyes). Patients' data were examined at 3, 6, and 12 months, and then every 6 months after surgery. We compared the groups' intraocular pressure (IOP), success ratio, visual acuity, number of glaucoma medications, central corneal endothelial cell density (CCECD), reduction ratio of CCECD, and postoperative complications.

The mean preoperative and postoperative IOP values were not significantly different between the two groups. In the Kaplan-Meier survival plots, there was no significant between-group difference in the success rate (p = 0.333). The postoperative mean CCECD decreased significantly faster in the AC group than the VC group at all time points. The cases of postoperative corneal edema were 12.5% in AC group and 1.8% in VC group. The risk of postoperative corneal edema was significantly higher in the AC group (p = 0.0136). Risk factors for the rapid reduction of CCECD were "history of trabeculectomy" (p = 0.00283), "insertion into the anterior chamber" (p = 0.001), and "shorter distance between the tube and corneal endothelium" (p = 0.0137).

There was no significant between-group difference in postoperative IOP, medications, or success rate. Considering the reduction of corneal endothelial cells, insertion into the vitreous cavity seems safer than insertion into the anterior chamber.