Long term effect of adjustable suture trabeculectomy on intraocular pressure

PURPOSE: Purpose of this retrospective study is to investigate long term intraocular pressure (IOP) outcome as well as complications associated with adjustable suture trabeculectomy in glaucoma patients who were uncontrolled under maximum medical therapy.MATERIALS AND METHODS: 35 eyes of 30 patients are included in the study. Adjustable suture trabeculectomy with 0.2mg/cc Mitomycin-C (MMC) for 3 minutes was performed by the same surgeon. 8 eyes had simultaneous phacoemulsification with intraocular lens implantation. Subconjunctival 5-Fluorouracil (5-FU) injection, transconjunctival suture adjustment, digital massage and/or argon suturolysis (ASL) were performed postoperatively as needed. Complete success, qualified success, and failure were defined as IOP?18mmHg without medication, IOP?18mmHg with one or more medication, and IOP>18mmHg with medication or additional surgery respectively.RESULTS: Of the 35 eyes, 13 had primary open angle glaucoma, 18 had psuedoexfoliative glaucoma and one had each of pigmentary, uveitic, chronic angle closure and juvenile glaucoma. Mean preoperative IOP of 30,0±10,5 mmHg dropped to 10,8± 4,6mmHg (P<0,001) after a mean follow-up of 595±435 days. 7 eyes had the desired IOP on first postoperative day where no adjustment was performed. Remaining 28 eyes required a mean of 3,0±1,6 adjustments among the first postoperative week in order to achieve a desirable IOP. ASL was performed in 8 eyes that did not achieve a desirable IOP despite suture adjustment. The number of glaucoma eye drops required was decreased from a mean preoperative level of 2,6 ± 0,5 to 0,3 ± 0,6 at final follow-up (P<0,001). Complete success, qualified success and failure was observed in 28 (80%), 5 (14%) and 2 (3%) of 35 eyes respectively. Choroidal detachment following ASL, intraocular hemorrhage during suture adjustment, tenon cyst, epithelial defect and suture exposition were each seen in one eye and did not need any intervention. Two eyes had bleb leaks that were controlled with the use of a bandage contact lens. Needling was performed to one eye.DISCUSSION: A desirable low IOP can be achieved with the use of adjustable sutures in trabeculectomy. Using a stringent criterion of ?18mmHg for complete success resulted in a success rate of 80% at a mean follow-up of 595 days. There were no serious complications that could be related to the surgery itself. We believe adjustable suture trabeculectomy to be a safe and effective alternative to standard trabeculectomy.KEYWORDS: Trabeculectomy, adjustable suture, mitomycin-C