The Singapore 5-fluorouracil trial: intraocular pressure outcomes at 8 years

Abstract

Objective: To report the 8-year outcomes of Asian subjects who underwent trabeculectomy augmented by intraoperative 5-fluorouracil (5-FU) or placebo.

Design: Retrospective review of a randomized controlled trial.

Participants: Subjects with primary open-angle or angle-closure glaucoma.

Methods: Study subjects were prospectively followed up for 3 years. After the last subject recruited had completed 8 years of follow-up, the charts of all subjects were reviewed to capture data from the year 3 visit onward. Kaplan-Meier survival function with Cox regression was performed to identify risk factors associated with trabeculectomy failure at 8 years.

Main outcome measures: The primary outcome was trabeculectomy failure defined as intraocular pressure (IOP) >21 or <6 mmHg on 2 consecutive occasions after the first 6 weeks after surgery, repeat glaucoma surgery, or loss of light perception. Further end points were defined at IOP levels >17 and >14 mmHg. Secondary outcomes included IOP at 8 years and number of glaucoma medications. Complete success was defined using IOP end points ≤ 21, ≤ 17, or ≤ 14 mmHg at 8 years without medications.

Results: Of the 243 enrolled subjects, 170 (70.0%) completed 8 years follow-up, 86 in the 5-FU and 84 in the placebo group. There was no significant difference in failure rates at 8 years for the failure definitions of IOP >21 mmHg (11.6% of the 5-FU group vs. 16.7% of the placebo group; P = 1.00), IOP >17 mmHg (23.3% of the 5-FU group vs. 31% of the placebo group; P = 0.78), and IOP >14 mmHg (46.5% of the 5-FU group vs. 58.3% of the placebo group; P = 0.37). Mean IOP at 8 years was 13.7 mmHg in the 5-FU versus 14.4 mmHg in the placebo group (P = 0.24). Mean number of medications was 0.65 drops in the 5-FU versus 0.93 drops in the placebo group (P = 0.06). Complete success with IOP ≤ 21 mmHg at 8 years was achieved in 48 subjects (55.8%) in the 5-FU and 33 subjects (39.3%) in the placebo group (P = 0.09). Absence of bleb microcysts at 1 year, preoperative IOP, and number of bleb needlings performed within the first year were significantly associated with failure.

Conclusions: There was no significant difference in IOP between the 5-FU and the placebo group at 8 years.

Financial disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.