Tamcelik et al. (955) present a comparative case series evaluating a novel surgical technique to prevent tube erosion following glaucoma drainage device (GDD) surgery. The study included 60 eyes of 58 patients who failed prior congenital glaucoma surgery and underwent Ahmed glaucoma valve placement. Patients were divided into two groups, including group 1 with 32 eyes of 28 patients who had classic Ahmed valve implant surgery and group 2 with 28 eyes of 24 patients who underwent the new technique. In the classic technique, the silicone tube was inserted through a corneal tunnel at the limbus. In the new technique, the tube was positioned through a 2-mm scleral tunnel and a Tenon flap fashioned from the posterior portion of the conjunctival flap was pulled anteriorly to cover the tube. After a mean follow-up of 31.68 ± 9.25 months, tube erosion was observed in 3 (9.4%) patients in group 1. No tube erosions were seen in group 2 with a mean follow-up of 34.96 ± 7.93 months.
An exposed tube provides a potential route by which bacteria can enter the eye and produce endophthalmitis
Tube erosion is an important complication of GDD surgery, as an exposed tube provides a potential route by which bacteria can enter the eye and produce endophthalmitis. Placement of a donor patch graft to cover the limbal portion of the tube has become a standard part of surgical implantation of GDDs to minimize the risk of this complication. Alternatively, some surgeons insert a GDD tube through a long scleral tunnel, but this approach may not be feasible in congenital glaucoma patients because of scleral thinning. The authors developed this new surgical technique combining a short scleral tunnel with Tenon advancement and duplication to prevent tube erosion in patients with congenital glaucoma without the need for a donor patch graft. There are several limitations of this pilot study. It would have been more valuable to compare the new surgical technique with the more standard approach of using a donor patch graft, rather than a limbal entry without a patch graft.
The novel technique was evaluated by a single surgeon at one site. Longer follow up is required to fully assess the safety and efficacy of this new approach. Despite these limitations, the authors are to be congratulated for introducing a novel surgical technique to prevent tube exposure after GDD surgery.