Anti-scars And Safety Studies Of Mitomycin C Subconjunctival Injection

Objective To observe anti-scarring effects and local organizations toxicities ofsubconjunctival injection of mitomycin C (MMC) on the scar model of rabbit eyes.Toexplore the feasibility and effectiveness as a support drug after glaucoma filtrationsurgery.Materials and methods 18 healthy adult New Zealand white rabbits were randomlydivided into the experimental group A, the control group B, and the control group C, 12eyes in each group, experimental scar model were established. Group A was givensubconjunctival injection of 0.4mg/ml MMC, and group B intraoperative subscleral flapplaced 0.4mg/ml MMC cotton for 5 minutes, group C subconjunctival injection of normalsaline (NS) after operation. Conjunctival imprint cytology (CIC) is to observe theconjunctival injury. 7 days, 14 days and 28 days after operation the rabbits were killedrespectively. Immunohistochemistry was used to observe fibroblast proliferation cellnuclear antigen (PCNA) expression, Application of physical examination and electronmicroscopy was used to study the pathological changes of surgical area.Results 1.After operation of the three groups, mild conjunctival hyperemia andcorneal spot epithelial defect of group A and group B disappeared after a week, cornealedema did not happen. 2. Conjunctival impression cytology showed group A and group Bwere 2-3 level and group C was 2 level. 3. Optical microscopy showed that belowconjunctiva infiinflammatory cells,fibroblasts,new blood capillaries and fibrous tissueproliferation increased significantly in group C than in group A and group B. 4.Immunohistochemical staining showed that the difference of PCNA-positive cell countbetween group A and group C, group B and group C had statistical significance, butgroup A and group B had no significant difference. 5.TEM showed the swelling ofmitochondrial and dissolution of outer membrane, rough endoplasmic reticulum,lysosome and nuclear membrane of conjunctival epithelial cells, the ultrastructure changeof cells in group A and group B was obvious than group C, but the difference betweengroup A and group B showed no significant difference.Conclusion Subconjunctival injection of MMC can effectively inhibit the scar formation after surgery, compared to the application of MMC during surgery, the extentof injury conjunctiva have no significant difference. The further study can hope to providea safe, effective and convenient means of local administration for anti-scarring afterglaucoma filtration surgery.