Inhibition of experimental intraocular proliferation with intravitreous 5-fluouracil. A transmission electron-microscopic study in rabbits.

5-Fluouracil, administered at concentrations of 1 and 5 mg to inhibit experimental intraocular proliferation produced by intravitreously implanted fibroblasts in rabbits, produced tissue alterations revealed by TEM. The degranulation and migration of pigment epithelial cells, the incipient degradation of axons and myelin sheets, the migration of glial cells and the prominent edema of the inner layers indicated a non-negligible damage to the retina, suggesting to abstain from its use in human eyes and to search for less neurotoxic drugs, possessing the same inhibitory effect on intraocular proliferation.