Purpose: To evaluate the safety and efficacy of a novel membrane-tube (MT)-type glaucoma shunt device for refractory glaucoma surgery. The device consists of an expanded polytetrafluoroethylene membranous reservoir, as well as a silicone tube (300-μm external and 200-μm internal diameter) with an intraluminal stent. We named the device "Finetube MT".
Methods: The Finetube MT was implanted into 44 glaucomatous eyes that had insufficient intraocular pressure (IOP) control despite medical treatment or previous trabeculectomy. The membranous reservoir was placed underneath the Tenon's capsule, with each end located below the recti muscles; the tube was placed in the anterior chamber through a partial-thickness scleral track. We investigated the baseline and post-operative IOP values, the number of IOP-lowering medications used, and complications.
Results: The mean age of the subjects was 51.6 ± 17.2 years, and the mean follow-up duration was 22.5 ± 12.0 months. One year after the surgery, the mean IOP had decreased from 32.8 ± 12.2 mmHg to 16.9 ± 6.4 mmHg (48.5 % reduction; p < 0.01), and the mean number of IOP-lowering medications used had decreased from 2.5 ± 0.8 to 1.1 ± 0.9 (p < 0.01). We considered the surgery as a success when the IOP was between 6 and 21 mmHg, and had been reduced by ≥ 20 % from baseline; by this standard, the success rate was 92.4 % after 1 year, and 85.0 % after 3 years. Neither postoperative ocular hypotony-related complications nor tube exposure occurred in any case.
Conclusions: The Finetube MT showed promising surgical outcomes as a treatment for refractory glaucoma, with minimal risk of postoperative ocular hypotony or tube-related complications.
Keywords: Glaucoma; Glaucoma drainage device; Intraocular pressure; Surgery; Trabeculectomy.