Background: Tube implants can lead to long-term decompensation of the cornea after decades, in particular in complicated childhood glaucoma, because of a variety of causes including contact between the tube tip and the corneal endothelium. The augmentation of a XEN implant with a Baerveldt (250) tube implant, introduced 2016 by Mermoud et al for refractory glaucoma in adult patients, may reduce this risk in children. In our retrospective study, we report on the XEN-augmented Baerveldt (250) tube implant in children.
Patients and methods: Ten consecutive patients with refractory childhood glaucoma who underwent XEN-augmented Baerveldt implantation by a single surgeon (F.G.) between January 2016 and August 2018 were retrospectively analyzed. In this technique, a XEN tube was inserted under a standard scleral flap from outside into the anterior chamber and its outer end was connected to the Baerveldt (250) tube. The follow-up consisted of regular anterior and posterior segment examination with intraocular pressure (IOP) measurements using a hand-held slit lamp and a Perkins applanation tonometer and/or rebound tonometer (Icare).
Results: Ten cases (6 female individuals, 4 male individuals, median age 6 years) were operated using a XEN-augmented Baerveldt implant [aphakic glaucoma, primary congenital glaucoma, secondary congenital glaucoma (Peters anomaly), ectropion uveae, and Stickler syndrome were 4, 3, 1, 1, and 1]. Before surgery (XEN-augmented Baerveldt implantation), median IOP was 31 mm Hg. At the last postoperative follow-up, the mean IOP was 18.5 mm Hg with a median follow-up period of 13 months (range, 3 to 21 mo). No shallow or flat anterior chamber was observed. In all cases, this technique could be performed without intraoperative complications. In 3 cases, however, a surgical revision was necessary. There was no prolonged postoperative hypotony or short-term corneal alteration. By using an S-shaped loop the original Baerveldt tube length could be preserved for potential future use. In a total of 6 out of 10 cases, the procedure was a complete success (IOP, ≤20 mm Hg without additional medication).
Conclusions: XEN-augmented Baerveldt implantation was used for refractory pediatric glaucoma in which conventional surgery had already failed. A new additional modification using an S-shaped loop was introduced. Short-term IOP control seems promising, but long-term results are still pending and the long-term efficacy and safety must still be proven before this technique can be generally recommended.