INTRODUCTION:
Prolonged postoperative hypotony has been a common and serious complication of
glaucomatous filtration surgery combined with mitomycin-C. In this study, the
toxic effects of mitomycin-C in cultured ciliary process and trabecular
meshwork cells in vitro were investigated. METHODS: The toxic effects of
mitomycin-C to cultured rabbit ciliary process and trabecular meshwork cells
were estimated by MTT method and 3H-thymidine uptake after 3 min, 5
min and 60 min treatment. The changes of intracellular Ca+2 in
trabecular meshwork cells and cAMP in ciliary process cells were measured. DNA
fragmentation was also performed on both tissues which were excised from rabbit
eyes. RESULTS: Mitomycin-C is more toxic to ciliary process cells than to
trabecular meshwork cells estimated by MTT and 3H-thymidine uptake.
Mitomycin-C at 10-3 mg/ml could inhibit 50 mM KCl-induced calcium
influx into trabecular meshwork cells. The cAMP concentration in ciliary
process cells was also inhibited by 10-3 mg/ml mitomycin-C after 3
min and 5 min exposure. In the presence of 10-3 mg/ml mitomycin-C
for 3 min and 5 min, DNA fragmentation was significantly observed in ciliary
process tissue but not in trabecular meshwork tissue. CONCLUSION: These
findings indicate that post-filtration hypotony may result from the toxicity of
mitomycin-C to ciliary epithelial cells and trabecular meshwork cells.