Comparison of Tenon duplication with dura mater covering technique for Ahmed glaucoma valve implantation

Purpose:To compare the efficacy and complications of Tenon duplication with dura mater covering technique for Ahmed glaucoma valve (AGV) implantation.Methods:This retrospective study included 44 refractory glaucoma patients (44 eyes) who underwent AGV implantation from 2017 to 2020 in the Ophthalmology Clinic of Eskisehir Osmangazi University Hospital and attended regular postoperative follow-ups. The patients were divided based on whether they underwent Tenon duplication technique (group 1: n = 20) or dura mater covering technique (group 2: n = 24) during surgery. The patients' age, gender, systemic diseases, glaucoma type, pre-op intraocular pressure (IOP), and ocular surgeries were recorded. The groups were compared for IOP level control, early and late complications, postoperative antiglaucomatous medication requirements, glaucoma surgery requirements, presence of postoperative hypertensive phase (HP), and surgical success which was defined as an IOP >= 5 and <= 21 mmHg, with or without antiglaucoma medication.Results:By the end of the mean follow-up (22.6 +/- 10.6 months), the success rates were 95% (group 1) and 96% (group 2). The groups showed no differences in postoperative complications, postoperative antiglaucomatous drugs' onset time, additional glaucoma surgery, need for needling, presence of HP at 6 months postoperatively, and relationship between the glaucoma type and success rates (P values: 0.86, 0.9, 0.48, 0.12, 0.36, and 0.8, respectively). The IOP values at the last follow-up were 15.2 +/- 4.1 in group 1 and 14.7 +/- 4.8 in group 2. The IOP reduction rates showed no significant differences.Conclusion:Since success and complications are similar in both Tenon duplication and dura mater covering technique, unique grafting materials may not be needed in AGV implantation surgery, except in special cases.