Effects of mithramycin, mitomycin, daunorubicin, and bleomycin on human subconjunctival fibroblast attachment and proliferation.

Scar formation and fibrosis are the most common causes of ultimate glaucoma filtration surgery failure. The authors used Coulter counter, hexosaminidase, and 3H-thymidine assays to evaluate the effects of mithramycin, mitomycin, daunorubicin, and bleomycin on human subconjunctival fibroblast growth in tissue culture. Fifty percent inhibitory doses (ID50) for each drug on different days of incubation with fibroblasts were calculated with these three assays. Among these four drugs only daunorubicin exerted a significant effect on cellular attachment, showing cytotoxicity at 4 x 10(-6) M. However, all drugs had antiproliferative effects. Daunorubicin was the most potent drug in the concentration range studied. Mithramycin had a narrow therapeutic range in tissue culture. Cellular antiproliferative responses to mitomycin and bleomycin were more gradual. These drugs have potential applications in the prevention of glaucoma filtration surgery failure.