Short-Term Effects of Subconjunctival Injections of 5-Fluorouracil on Conjunctival Epithelium

Abstract

To assess the changes in the conjunctival cytology of patients given a subconjunctival injection of 5-fluorouracil (5-FU) to treat failed filtering blebs. The patients were classified into 3 groups. The first group included 15 eyes in 15 patients who were given subconjunctival injections of 5-FU after unsuccessful glaucoma surgery. The second group consisted of 15 eyes of 15 patients with primary open angle glaucoma treated with antiglaucomatous eyedrops. Twelve healthy age- and sex-matched volunteers formed the third group. Impression cytology specimens were obtained from the bulbar conjunctiva just beside the injection sites using cellulose acetate filter paper. The samples were fixed in 95% ethanol, stained with Papanicolaou stain, and evaluated under light microscopy and graded. In the first group, grade 0-3 cytological changes were seen in 1 eye (6.6%), 9 eyes (60%), 4 eyes (26.6%), and 1 eye (6.6%). Apoptosis was observed in 2 eyes (13%) and nuclear atypia in 7 eyes (47%). In the second group, 9 eyes (60%) were grade 0, 4 eyes (27%) were grade 1, and 2 eyes (13%) were grade 2. Also, nuclear atypia was observed in 1 eye (6.6%). In the third group, 10 eyes (83%) were grade 0 and 2 eyes (17%) were grade 1. There was no significant difference in terms of the impression cytology grades between the groups because of small sample size. The use of subconjunctival 5-FU injections after glaucoma surgery may lead to squamous metaplastic changes and nuclear atypia and apoptotic cell death in the conjunctival epithelium in short-term period.