Purpose: To determine the efficacy and safety of subconjunctival 5- fluorouracil injections after trabeculectomy in patients with poor prognoses, to determine risk factors for surgical failure and to examine the relationship of intraocular pressure and visual function.
Methods: In this multicenter clinical trial, 213 patients with previous cataract surgery or previous failed filtering surgery were randomly assigned to receive either trabeculectomy alone or trabeculectomy with postoperative subconjunctival 5-fluorouracil injections. Measurements of intraocular pressure, visual acuity, and visual fields were performed throughout the five years, with the clinician masked to the treatment group. Failure was defined as a reoperation to control intraocular pressure or an intraocular pressure greater than 21 mm Hg at or after the first-year examination.
Results: Fifty-four (51%) of the 105 eyes in the 5-fluorouracil group and 80 (74%) of the 108 eyes in the standard filtering surgery group were classified as failures (P < .001, Mantel-Cox survival analysis). Risk factors for failure include high intraocular pressure, a short time interval after the last procedure involving a conjunctival incision, the number of procedures with conjunctival incisions, and Hispanic ethnicity. Patients in both treatment groups with controlled intraocular pressures were more likely to maintain visual acuity. Patients in the 5-fluorouracil group had a higher risk of late-onset bleb leaks (9% nine of 105) than those in the standard filtering surgery group (2% two of 108) (P = .032, Fisher's exact test).
Conclusions: We recommend the use of subconjunctival 5-fluorouracil after trabeculectomy in eyes after previous cataract surgery or unsuccessful filtering surgery, but caution against its routine use in patients with good prognoses.