The Effects Of Applying Dexamethasone To Filtering Surgery In Rabbits

Objective:Glaucoma is the most popular ophthalmological disease, trabculectomy has been the frequently surgery mode for many years, the successful probability of trabculectomy is affected by many factor although it has improved many times. The important reason is surgery induce issue wound , make filtering blebs into scar and fibro issue fill in subconjunctiveal ,all that make trabculectomy lost.Recent years , the successful probability of trabculectomy is advanced greatly with using anti-metabolize drugs such as mitomycine(MMC), 5-fluorouracil(5—Fu) abroadly. But also bring some new complications such as hypotension after surgery and filtering blebs effusion. It's a exactly resolved problem that how to improve the rate of successful at the same time decrease the complications. Corticosteriod effects inhibition fibroblasts hyperplasia, or indirect inhibition the local inflammation of fibroblasts hyperplasia by anti-inflammation action, inhibition collagen fibers compose, accordingly make scar lighten.The research of anti-scar is few, although it's effect of anti-inflammation is popular. Our research is looking for the proof of corticosteriod can decrease scar forming, and grope for new anti-scar drugs.Methods:Normal rabbits were randomly divided into two groups. First group: choose one eye randomly performs trabculectomy alone (named TR team),another one performs trabculectomy with topical application DEX(named TR+DEX team);second group:choose one eye randomly performs trabculectomy with topical application MMC(named TR+MMC team);another one performs trabculectomy with topical application DEX(named TR+DEX team).The tissue of surgical field of two eyes of rabbits was obtained postoperatively days 3, 7,14 and 28.1) The changes of intraocular pressure(IOP) preoperatively and postoperatively also different time points and grade of blebs were compared .2) Observe the histopathologic changes of filtering blebs by H-E & Masson coloration , evaluate effect of anti-scar that drugs application in filtering surgery.Result:1.Intraocular pressure postoperatively days 3, 7, 14 and 28 compare with preoperatively, significantly reduced;There was significant statistical difference in Intraocular pressure postoperatively between TR+MMC team and TR+DEX team in postoperatively days 3;There was no significant statistical difference in Intraocular pressure postoperatively between TR+MMC team and TR+DEX team in postoperatively days 7> 14 and 28, but there was significant statistical difference between TR+MMC team and TR team, the same as TR+DEX team and TR team.2. The numbers of fibroblasts and inflammation blasts in TR+DEX team as well as TR+MMC were significantly reduced (p<0.05) compared to TR team. There was no significant statistical difference in the numbers of fibroblasts between TR+MMC team and TR+DEX team. (p>0.05)3.The space under conjunctiva in TR+DEX team as well as TR+MMC were significantly statistical difference (p<0.05) compared to TR team. There was no significant statistical difference in the numbers of space between TR+MMC team and TR+DEX team (p>0.05)Conclusions:1.Significant statistical difference in intraocular pressure postoperatively between three teams show that trabculectomy with topical application dexamethasone can decrease intraocular pressure effectively and make surgery successful.2.Trabculectomy with topical application dexamethasone can inhibition fibroblasts hyperplasia and filtering bleb scared, it is safely and effectively.