Comparison of 5-year outcomes between trabeculectomy combined with phacoemulsification and trabeculectomy followed by phacoemulsification: a retrospective cohort study

Background We aimed to compare the outcomes of trabeculectomy combined with phacoemulsification and those of trabeculectomy followed by phacoemulsification. Methods A total of 141 patients with primary open-angle glaucoma, exfoliation glaucoma, and glaucoma secondary to uveitis glaucoma who underwent trabeculectomy followed by (n = 48) or combined with (n = 93) phacoemulsification were included. We analyzed data collected from the Collaborative Bleb-Related Infection Incidence and Treatment Study, a prospective cohort study conducted in 34 clinical centers that included 1249 eyes. The main outcome was the cumulative probability of success based on intraocular pressure (IOP) within 5 years. Surgical failure was defined as a case in which additional glaucoma surgery is required or one of the following criteria are met: preoperative IOP > 21 (A), > 18 (B), or > 15 mmHg (C). The secondary outcomes were cumulative probability of success, risk factors of surgical failure, and Delta visual acuity. However, the data on phacoemulsification during the 5-year follow-up were censored. Results No significant difference was found in the cumulative probability of success as the main outcome. When the data on phacoemulsification during the 5-year follow-up were censored, the probabilities of success of trabeculectomy followed by phacoemulsification were significantly higher for criteria A (p = 0.02), B (p < 0.01), and C (p < 0.01). Lower preoperative IOP, younger age, and trabeculectomy combined with phacoemulsification were associated with poorer outcome. Trabeculectomy followed by phacoemulsification had significantly worse Delta logMAR visual acuity at 6 and 12 months (p < 0.01). Conclusion The cumulative probability of success after trabeculectomy combined with or followed by phacoemulsification remained unchanged. Combining phacoemulsification with trabeculectomy adversely affected the cumulative probability of success after trabeculectomy. The visual acuity improvements observed in the early postoperative period after combining phacoemulsification with trabeculectomy disappeared within 5 years.