Effects of varying 5-fluorouracil exposure duration on tenon's capsule fibroblasts.

5-Fluorouracil (5-FU) is used intraoperatively to improve the success of trabeculectomy Common practice is a 5-min application of 5-FU delivered via a Weck Cel sponge. The aim of this study was to determine if shorter exposure times were as effective in inhibiting Tenon's capsule fibroblast proliferation. Samples of Tenon's capsules, obtained from young patients undergoing strabismus surgery, were immersed In vitro in 5-FU (50 mg/mL) for periods ranging from 1 to 10 min. Control samples were exposed either to growth medium (M 199) or 5-FU vehicle alone. Explants were cultured for up to 7 days and analysed for cell density, cell viability using fluoroprobe detection, and cell proliferation determined by proliferating cell nuclear antigen (PCNA)-staining. Exposure to 5-FU for 1 and 5 min resulted in a similar and significant inhibition of the culture-induced increase in stromal cell density (P < 0.01), a significant reduction in the percentage of viable cells (P < 0.02), and reduced PCNA indices, compared with controls. Exposure times of 3 and 10 min produced similar results. In vitro, under conditions of organ culture, a 1-min exposure to 5-FU had a significant antiproliferative effect on fibroblasts of Tenon's capsule, and was similar to 5 min of exposure. Optimal intraoperative 5-FU exposure time may be as little as 1 minute.