Anti-allergic drugs inhibit the proliferation of human Tenon's capsule fibroblast and maintain the experimental filtering blebs on rabbit eyes

PURPOSE: To examine whether tranilast and ketotifen fumarate inhibit the growth of human Tenon's capsule fibroblasts and maintain experimental filtering blebs on rabbit eyes. METHODS: Human Tenon's capsule fibroblasts were grown in Dulbecco's modified Eagle's medium with 10% fetal calf serum and growth was measured with 3-4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and direct counting of cell number. Production of collagen and transforming growth factor-beta 1 (TGF-beta 1) was measured with corresponding enzyme-linked immunosorbent assay (ELISA). In experimental filtering surgery performed on rabbit eyes, the effects of the topical drugs on intraocular pressure and on maintenance of the filtering blebs were observed. RESULTS: Both tranilast and ketotifen inhibited the growth of the fibroblasts and half-inhibitory concentrations were 200 microM and 70 microM, respectively. Low concentration (10 microM) of tranilast and ketotifen decreased the synthesis of collagen but neither drug had any obvious effect on TGF-beta 1 production. Both drugs prolonged the life of the experimental filtering bleb significantly 12.5 +/- 3.2 (mean +/- standard deviation) days, 13.9 +/- 3.4 days, respectively; control, 10.5 +/- 2.4 days]. CONCLUSION: Tranilast and ketotifen inhibited the growth of human Tenon's capsule proliferation and are capable of maintaining experimental filtering blebs in rabbit eyes.