Topical application of amniotic membrane extract at a clinically correlated dose is effective in limiting complications in an experimental ocular alkaline burn model

Abstract

The purpose of this study is to investigate the clinical and histopathological effectiveness of topical amniotic membrane extract (AME) applied at a clinically relevant dose in an experimental corneal alkaline burn model and to compare the results with amniotic membrane transplantation (AMT) as one of the most frequently used biologically based treatment options. To create an alkaline burn model, NaOH-impregnated filter paper was applied to all rabbits for 30 s. Rabbits were divided into 3 groups: Group 1 (n = 6): AME eye drop; Group 2 (n = 6): AMT; Group 3 (n = 4): control group. AME eye drops were applied as 1 drop 4 times a day for 28 days. Clinical findings including corneal opacity, corneal vascularization, limbal stem cell deficiency (LSCD) was evaluated and graded in accordance with the updated literature. On day 28, corneas were histopathologically examined under the light microscope. Stromal inflammation, stromal fibrosis, intraepithelial edema, and corneal vascularization were scored in each group. When the groups were compared clinically, corneal opacity was significantly (p = 0.009) lower in the AME group. While lower LSCD grades were observed in the AME group, this difference was not significant (p > 0.05). Histopathologically; in the AME group, stromal inflammatory cell inflammation, corneal vascularization, intraepithelial edema, stromal fibrosis, and metaplastic epithelial layer thickness were significantly (p = 0.004; p = 0.022; p = 0.008; p = 0.002; p = 0.002, respectively) lower than the other groups.In this study, it was shown that AME eye drops were clinically and histopathologically more successful in providing corneal healing than the AMT and control groups in the ocular alkaline burn model. These findings are valuable as they show that AME eye drops may be an easy-to-apply biologically based treatment alternative to AMT in chemical burns.