PURPOSE: To assess the influence of the antiproliferative agent (5-FU) on the intact rabbit corneal epithelium. METHODS: 10 rabbits (14 eyes),were divided into: control group (CG), 4 eyes without drug administration; G1, 5 eyes underwent treatment with topical 12.5 mg/ml 5-fluorouracil and G2, 5 eyes received 5-fluorouracil in the concentration of 25 mg/ml. Topical 5-fluorouracil was administered four times daily for 7 days. Then the animals were sacrificed, the cornea was removed and fixed in 2% glutaraldehyde solution and the corneal specimens were prepared for scanning electron microscopy (SEM). RESULTS: CG: the corneal surface in normal rabbits are composed of characteristic flat polygonal cell arranged in a mosaic pattern, in which light, dark and intermediate cells were distinguishable. Light cells have the most numerous microplicae. The crypts were randomly distributed over the surface, one to three were founded on each cell. G1: dark cells were present in a higher number than white cells, with a tower number of crypts, surface alterations, exposing the nucleus and desquamative cells. G2: increase of microprojections, disrupted attachments with adjacent cells, decrease in number and variability of crypt size. These alterations appeared mainly at the peripheral cornea. CONCLUSION: 5-fluorouracil caused discernible changes in the intact rabbit cornea. These changes were more evident in eyes wich received the drug at a higher concentration, and appeared mainly at the peripheral cornea.
Fluorouracil; Cornea; corneal; Microscopy; electron; scanning; Rabbits; Ophthalmic solutions
