The Effects of the Application of Human Amniotic Membrane Ointment in Filtering Surgery on Rabbits

ABSTRACT

PURPOSE: We investigated the anti-inflammatory and anti-fibrotic effects of amniotic membrane(AM) ointment in filtering surgery of rabbits. METHODS: After filtering surgery was performed on both eyes of 10 rabbits, the AM ointment was applied over and under the scleral flap on one eye whereas base ointment excluding AM element was applied to the other as a control. The shapes of blebs were observed under slit-lamp biomicroscopy at postoperative 3 days, 1 week, 2 weeks and 4 weeks, and the tissues were excised for histologic studies. RESULTS: Serial changes of intraocular pressures had no significant difference. Slit-lamp biomicroscopy demonstrated that conjunctival blebs of AM ointment group were more elevated and cystic at 1 and 2 weeks. The heights of conjunctival blebs were significantly higher at 1, 2 and 4 weeks, and the width of scleral tracks was significantly wider at 1 and 2 weeks in AM ointment group. The number of inflammatory cells in the scleral track was significantly less at 3 days and 1 week, the number of fibroblasts in scleral track was significantly less at 2 and 3 weeks in AM ointment group. Masson s trichrome stain was less positive in AM ointment and the stain area of alpha-smooth muscle actin-positive fibroblasts was insignificant with image analysis system. Collagen type 3 appeared in scleral track from postoperative 1 week in control group, however, in AM ointment group, from 4 weeks. CONCLUSIONS: AM ointment is beneficial to suppress fibroblast differentiation, proliferation and inflam-matory reaction in filtering surgery and might be safe and effective adjunctive for enhancement of success in filtering surgery.