PRIMATE TRABECULECTOMIES WITH 5-FLUOROURACIL COLLAGEN IMPLANTS

Bilateral trabeculectomies were performed on four normal cynomolgus monkeys. Highly purified bovine skin collagen implants with either 1 mg of 5-fluorouracil or physiologic saline (one each per monkey by randomized, masked assignment) were sutured under the scleral flaps. The randomization code was not broken until all clinical and histopathologic observations had been completed. Six weeks postoperatively, the 5-fluorouracil-treated eyes had more deeply open internal trabeculectomy ostia than the control eyes; however, the intraocular pressures were indistinguishable, the filtering blebs were only minimally different, and half of each group had trace or mild anterior subcapsular lenticular changes. Histologically, a multinucleated foreign body giant cell reaction was evident in all of the collagen implants, but the 5-fluorouracil-treated eyes had less vigorous or delayed reactions compared to the control eyes. The collagen implant appears to be a poor drug delivery system in this model of glaucoma filtering surgery, because it incites a granulomatous inflammatory reaction.