Associations and Outcomes Comparing First and Second-Eye Trabeculectomies in Patients With Glaucoma.

Prcis: The present study highlights the high correlation of outcomes of bilateral trabeculectomy in subjects with different types of glaucoma after mid-term follow-up.

Purpose: To evaluate the mid-term outcomes of bilateral trabeculectomy and assess the differences and associations in outcome between the first-operated and the second-operated eye.

Methods: Patients with different types of glaucoma who underwent bilateral trabeculectomy from 2006 to 2022 were included in this retrospective study. All patients were followed for at least 24 months after surgery in each eye. The main outcome measure was surgical success. Complete success was defined according to intraocular pressure (IOP)≤16 mmHg and at least 20% reduction from preoperative baseline IOP without any IOP-lowering medications. Cumulative success was defined according to IOP≤16 mmHg and at least 20% reduction from preoperative baseline IOP, with or without IOP-lowering medications. Secondary outcome measures were IOP and the number of IOP-lowering medications.

Results: In total, 186 eyes of 93 patients were included. There was no statistically significant difference in terms of the baseline IOP and number of IOP-lowering medications between the first and second-operated eyes before and after surgery ( P >0.05). The mean follow-up time was 64.35±41.13 months and 57.13±38.41 months for the first-operated and the second-operated eyes, respectively. At the 24-month follow-up point, among patients whose first operated eyes were considered a complete success, 78.2% of surgeries in second eyes were successful ( P =0.002). In contrast, among patients whose first operated eyes were considered a cumulative success, 80.3% of surgeries in second eyes were successful ( P =0.012). In a multivariate analysis of factors affecting cumulative success, the outcome of the surgery in the first-operated eye was the only factor that significantly impacted the outcome of surgery in the second-operated eye. If the first-operated eye achieved cumulative success, the odds of the second-operated eye experiencing cumulative success were 6.5 ( P =0.02). The rates of postoperative complications in the 2 eyes were similar and did not show statistically significant differences.

Conclusion: The present study demonstrates a significant correlation in surgical outcomes of trabeculectomy between the 2 eyes of the same patient in mid-term follow-up. Surgical success in the first-operated eye increases the odds of success in the second eye 6.5-fold.