Objective: A prospective randomized and placebo-controlled study was performed to evaluate the effect and toxicity of injectable bioerodible polymer with 5-fluorouracil (5-Fu) on the filtration surgery in rabbits.
Methods: Posterior lip sclerectomies were performed on both eyes of 23 rabbits. Injectable bioerodible polymer impregnated with 2.5% 5-Fu 10 mg was injected subconjunctivally in 16 eyes, and 2.5% 5-Fu 10 mg was injected subconjunctivally in 14 eyes every other day for three times in the first week and every two days for three times in the second week post-operatively. Another 16 eyes received the drug-free polymer after surgery and served as controls.
Results: The bleb in the eyes treated with drug-free polymer failed in the postoperative 7 days and the bleb in the eyes treated with 5-Fu injection failed in 20-30 days, while the bleb in the eyes treated with 5-Fu polymer remained successful throughout the experimental period. From 7 to 30 postoperative days, the rate of scleral fistula occlusion was 6.7% in the eyes treated with 5-Fu polymer, 41.7% in the eyes treated with 5-Fu injection and 100% in the eyes treated with drug-free polymer. Corneal epithelial defects appeared in 3 eyes treated with 5-Fu polymer, in 8 eyes treated with 5-Fu injection and in 2 eyes treated with drug-free polymer.
Conclusion: Injectable bioerodible polymer with 5-Fu may significantly prevent bleb scarring and subsequent blockage of the filtering tract, enhance success rate of filtering surgery in rabbits and reduce the toxicity of 5-Fu. This drug delivery system has considerable value for clinical use.