Ahmed Glaucoma Valve Implantation: Graft-Free Short Tunnel Small Flap versus Scleral Patch Graft after 1-Year Follow-up: A Randomized Clinical Trial

Abstract

To compare the efficacy and safety of the graft-free short tunnel small flap (STSF) technique with that of the scleral patch graft (SPG) in Ahmed glaucoma valve (AGV) (New World Medical Inc, Rancho Cucamonga, CA) implantation. Randomized clinical trial. A total of 203 eyes of 203 patients with medically uncontrolled glaucoma, including 102 in the STSF group and 101 in the SPG group. Patients were enrolled and assigned randomly to STSF or SPG. Tube exposure, intraocular pressure (IOP), number of glaucoma medications, best-corrected visual acuity, surgical complications, and success rate (defined as IOP >5 mmHg, ≤21 mmHg, and IOP reduction ≥20% from baseline at 2 consecutive visits after 3 months, no reoperation for glaucoma). Only 1 patient in the SPG group developed tube exposure at 1-year follow-up. The cumulative probability of success during the first year of follow-up was 70% in the STSF group and 65% in the SPG group (P= 0.36). The IOP decreased significantly from 29.6±8.6 mmHg at baseline to 16.4±3.6 mmHg at the final follow-up in the STSF group (P= 0.001). The corresponding numbers for the SPG group were 30.9±11.2 and15.8±4.7, respectively (P= 0.001). The final IOP was comparable between both groups (P= 0.65). Mean±standard deviation of the number of glaucoma medications was 1.8±0.9 in the STSF group and 1.6±0.9 in the SPG group at final follow-up (P= 0.32). Postoperative complications developed in 8 patients (19%) in the STSF group and 9 patients (23%) in the SPG group (P= 0.81). The STSF and SPG techniques had a comparable complication rate at the 1-year follow-up. Both techniques were comparable in terms of success rate, postoperative IOP, and glaucoma medications.