The Effect of Amniotic Membrane Ointment on Prevention of Adhesion in Strabismus Surgery in Rabbits

PURPOSE: The authors investigated the anti-inflammatory and the anti-fibrotic effect of amniotic membrane ointment on preventing adhesion in strabismus surgery in the rabbits. METHODS: Recession of superior rectus muscle was performed in 64 eyes of 32 rabbits and then the 32 rabbits were divided into 4 groups each 16 eyes of 8 rabbits. control group received no more treatment. 0.04% mitomycin C, base ointment, and amniotic membrane ointment were applied to the other trial groups respectively. Histopathologic studies was performed in 3 days, 2 weeks, 4 weeks, 12 weeks and evaluated the change of inflammation and fibrosis. The degree of inflammatory cell infiltration was evaluated on H and E stain and the degree of fibrosis was evaluated on Masson-trichrome stain. An immunohistochemical stain for alpha-smooth muscle actin was done for detection of myofibroblasts. RESULTS: On postoperation 3 days, 2 weeks, 4 weeks, the amniotic membrane ointment group and the mitomycin C group showed less inflammatory cell infiltration than control group(P<0.05). Masson-trichrome stain showed less fibrosis in the amniotic membrane ointment group and the mitomycin C group. The degree of immunohistochemical stain for alpha-smooth muscle actin was observed to be lower in the mitomycin C group and amniotic membrane ointment group than in the other groups during all period of observation. CONCLUSIONS: Amniotic membrane ointment might be effective adjuvant for prevention of postoperative adhesion in strabismus surgery.

The Effects of Amniotic Membrane Ointment on Corneal Alkali Burn in Rabbits

PURPOSE: The therapeutic effects of amniotic membrane transplantation (AMT) contain anti-fibrosis, anti-inflammation and facilitation of epithelialization. Thus we investigated whether applying of amniotic membrane (AM) ointment could get the same effect as AMT. METHODS: Alkali burn was induced by applying 6 mm round filter paper which was soaked with 1 N NaOH, onto the central cornea for 60 seconds on both eyes of 10 white rabbits. Then we applied AM ointment on one eye and base ointment on the other eye, four times a day for 1 week. The corneas were harvested for histopathologic studies at 1 day and 3 weeks. Corneal opacity and thickness were measured in 3 days and 1, 2, 3 weeks. RESULTS: In the AM ointment applicated group, the number of the infiltrated PMNs (polymorphonuclear cells) and apoptotic keratocytes were significantly less than that of the control group (p< 0.05). The degree of lipid peroxidation and myofibroblast differentiation were less than those of the control group. Corneal opacity and corneal edema were less in AM ointment group than control group. CONCLUSIONS: AM ointment application after alkali burn is beneficial to reduce inflammation, keratocyte apoptosis and lipid peroxidation, and is considered to suppress corneal haze by these effects. Therefore, this report may be a basic study for the AM ointment research to treat recalcitrant keratitis.

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

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.

The Effects of Amniotic Membrane Ointment Application on Photore fractive Keratectomized Cornea in Rabbits

The authors investigated the effects of amniotic membrane ointment on inflammatory cell infiltration into corneal stroma, early keratocyte and inflammatory cell apoptosis and lipid peroxidation of cell membrane after photorefractive keratectomy (PRK) in rabbits. PRK was performed on both eye of 10 white rabbits, then we applied amniotic membrane ointment on one eye and ointment base on the other eye, three times a day, respectively. All corneas were harvested after 24 hours. Hematoxylineosin (H&E) stains for polymorphonuclear cells (PMNs) infiltration, terminal deozyribonucleotidyl transferase mediated dUTP-digoxigenin nick end labeling (TUNEL) stains for keratocyte apoptosis and malondialdehyde (MDA) immunohistochemical stains for lipid peroxidation were performed. In amniotic membrane ointment applicated group, PMNs in corneal stroma, TUNEL stain positive cells and degree of lipid peroxidation were significantly less than those of base ointment applicated group (P<0.05). Therefore, those findings may be able to utilize as basic data for clinical use of amniotic membrane ointment.