Risk of endophthalmitis and other long-term complications of trabeculectomy in the Collaborative Initial Glaucoma Treatment Study (CIGTS)

Abstract

Purpose: To report the risk of endophthalmitis and other long-term complications in patients randomized to trabeculectomy in the Collaborative Initial Glaucoma Treatment Study.

Design: A longitudinal cohort study using data collected from a multicenter, randomized clinical trial.

Methods: Long-term postoperative complications in the 300 patients randomized to trabeculectomy in the Collaborative Initial Glaucoma Treatment Study were tabulated. Kaplan-Meier analyses were used to estimate the time-related probabilities of blebitis, hypotony, and endophthalmitis.

Results: Two hundred eighty-five patients were included in the final trabeculectomy cohort after accounting for declining treatment assignment and other early events. Patients were followed up for an average of 7.2 years. One hundred sixty-three patients (57%) received 5-fluorouracil during surgery. Of the 247 patients with at least 5 years of follow-up, 50 required further treatment for glaucoma. Cataract extraction was performed in 57 patients (20%). Forty patients (14%) required bleb revision at least once. Bleb-related complications included bleb leak (n = 15), blebitis (n = 8), and hypotony (n = 4). Three patients were noted to have endophthalmitis, although the diagnosis in 2 patients was presumptive. The occurrences of blebitis, hypotony, or endophthalmitis were not significantly associated with 5-fluorouracil use. The Kaplan-Meier calculated risks of blebitis and hypotony at 5 years were both 1.5%, whereas the risk of endophthalmitis was 1.1%.

Conclusions: The potential efficacy of trabeculectomy must be weighed against the long-term risk of complications, especially endophthalmitis, when selecting treatments for patients with open-angle glaucoma. We report a low 5-year risk of endophthalmitis (1.1%) and other bleb-related complications in the trabeculectomy cohort of the Collaborative Initial Glaucoma Treatment Study.

Figure 1. Risk of Blebitis, Hypotony, and Long-Term Endophthalmitis in the Collaborative Initial Glaucoma Treatment Study (CIGTS) Initial Trabeculectomy Cohort

Kaplan-Meier analysis was used to calculate the probability of blebitis, hypotony and endophthalmitis during 5 years of follow-up. Based on 8 documented cases, the probability of blebitis (upper) during 5 years of follow-up was 0.015. The probability of hypotony (middle) based on 4 documented cases was 0.015; one of these patients was noted to exhibit hypotony maculopathy. Finally, three patients in the CIGTS initial trabeculectomy cohort were noted as having endophthalmitis, resulting in a 5-year Kaplan-Meier probability of endophthalmitis of 0.011 (lower). As described in the text, the diagnoses in two of these patients were presumed based on requirement of hospitalization, though the route of antibiotic administration is unclear. Excluding these two patients, the 5-year probability of endophthalmitis is 0.004.