Efficacy of Single-site versus Two-site Phacotrabeculectomy in Primary Open-angle Glaucoma: A Prospective Cohort Study

Abstract

Introduction: The prevalence of co-existing cataract and glaucoma is increasing in the adult population. Combined surgeries have become more popular. However, there is a conflict over which technique provides the best Intraocular Pressure (IOP) control with good postoperative outcomes. Aim: To compare the efficacy of single-site versus two-site phacotrabeculectomy with mitomycin-C in patients with Primary Open-angle Glaucoma (POAG) and cataract. Materials and Methods: A prospective cohort study was conducted in the Department of Ophthalmology, S.V. Medical College, Tirupati, Andhra Pradesh, India, over a period of one year from January 2019 to January 2020. A total of 50 cases of POAG coexisting with cataract were analysed in the present study. Twentyfive cases were included in each group (Group-1 and Group-2). Phacoemulsification and trabeculectomy were both performed through a superior scleral tunnel in the single-site approach. The two-site method combines a superior trabeculectomy with a temporal clear corneal phacoemulsification. A concentration of 0.2 mg/mL of MMC was applied in both groups for three minutes. Patients were followed-up for three months after surgery to evaluate Intraocular Pressure (IOP), the need for antiglaucoma medication, and postoperative best-corrected Visual Acuity (VA). Comparative analysis was done using the Student’s t-test, and a p-value <0.05 was considered statistically significant. Results: Throughout the three-month duration, the patients were monitored. In the single-site group, the average preoperative IOP was 21.880±8.4079 mmHg, which significantly decreased to 11.16±9.95 mmHg after three months (p<0.001). In the twosite group, the corresponding figures were 22.640±6.3040 and 10.8±1.19 mmHg, respectively (p<0.001), with no discernible statistical distinction between the two groups (p=0.486). At the final follow-up, the number of antiglaucoma medications was 0.24±0.5 in the single-site group compared to 0.16±0.24 in the two-site group. The mean postoperative Best Corrected Visual Acuity (BCVA) did not exhibit any significant variation between the two groups. Furthermore, there was no disparity in the occurrence rate of complications between the two groups. Conclusion: Both single and two-site phacotrabeculectomy led to a significant reduction in IOP and improvement in BCVA. The final IOP was similar in the two procedures, although the twosite group needed less glaucoma medication. As both surgical procedures are equally effective, the choice of procedure remains at the discretion of the surgeon.