Long-term outcome of stab incision glaucoma surgery versus trabeculectomy surgery in the management of primary open angle glaucoma

Purpose To assess the long-term outcome of Stab incision glaucoma surgery (SIGS) and compare it with subscleral trabeculectomy (SST) in the management of open-angle glaucoma (OAG). Methods Twenty eyes of 20 OAG patients were randomly assigned into group 1: 10 patients underwent SIGS + Mitomycin C (MMC), and group 2: 10 patients underwent SST + MMC. The patients were followed-up over 2 years after surgery. Our outcome measures were: Postoperative intraocular pressure IOP, number of medications used, and postoperative complications. Results Twenty-four months postoperatively, the mean IOP was 13.78±2.05 mmHg in the SIGS group compared with preoperative IOP of 26.33±5.1 mmHg (P <0.001, paired t-test), and 14.38±4.56 mmHg in SST group compared with preoperative IOP of 30.13±7.51 mmHg (P <0.001, paired t-test). No significant differences in mean IOP between groups either preoperatively (P=0.15) or along follow-up (P=0.62 at last visit). The mean IOP drop from baseline was 12.56±5.00 mmHg (46.33±10.50%) in SIGS group and 15.75±8.22 mmHg (49.50±17.95%) in SST group (P=0.26). A significant decrease in the number of glaucoma medications was noted in the SIGSS group (P <0.001), in the SST group, the number decreased but was not statistically significant (P =0.120). Conclusion SIGS is comparable with SST in achieving long-term significant and maintained IOP reduction over up to 2 years, in addition to decreasing the number of antiglaucoma medications postoperatively. SIGS is recommended for surgical management of primary OAG as it has the advantage of being a faster, easier, less traumatic alternative to conventional SST with fewer complications.