Double scleral tunnel technique to prevent glaucoma drainage device exposure

PURPOSE: To describe a new surgical technique designed to reduce the risk of tube exposure following glaucoma drainage device (GDD) surgery. METHODS: A retrospective, single-center study included all patients who underwent GDD surgery by a single surgeon between January 2018 and December 2019, using a double scleral tunnel technique to secure the tube to the sclera. A 23-gauge needle was used to create a 3 mm partial thickness scleral tunnel near to the GDD plate, with a second partial thickness scleral tunnel created 2.5 mm from the surgical limbus into the anterior chamber (AC). The silicone tube was passed through both scleral tunnels and into the AC. RESULTS: 46 GDD surgeries were performed during the time frame. The mean age of patients was 65 ± 13 years. Mean follow up duration was 27.7 ± 8.15 months (range 11 to 44). Significant reductions in intraocular pressure and number of glaucoma medications were achieved. Zero exposures were recorded occurring during follow-up. CONCLUSION: This double scleral tunnel technique to secure the GDD silicone tubing firmly to the sclera may reduce micro-movements which have been purported to be associated with tissue erosion post GDD surgery. The addition of this simple technique to existing GDD surgery may reduce the risk of post-operative tube exposure.