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Abstract
Amniotic membrane (AM), or amnion, is the innermost layer of the placenta.
It consists of a thick basement membrane, avascular stromal matrix with fibroblasts, collagen and other cellular components and has an ectodermic monolayer of epithelial cells.
In recent years, preserved human AMT has been advocated for the management of a variety of corneal surface disorders.
Various pathological changes can affect the ocular surface resulting in epithelial defect formation that may become persistent if normal epithelialization processes fail.
A delay in epithelialization can lead to the formation of permanent anterior stromal opacification, corneal ulceration with thinning, or even perforation.
Following the work of Kim and Tseng, in 1995, the use of AM in ocular surface pathology has been revived with favorable results in the treatment of different corneal ulcers.
Amniotic membrane, when used as a graft to cover corneal ulcers, acts like a basement membrane. Because its structure and the presence of growth factors, it favors the growth of epithelial tissue over it, thus restoring the ocular surface.
When AM is used as a patch, it acts as therapeutic contact lens. Epithelialization occurs underneath the AM.
The membrane neither is trapped within the cornea nor affects the transparency of the cornea once it has been eliminated.
Our study included 30 cases with resistant corneal ulcer with different causes.
The mean age in this study was 54.5 years.
The sex distribution showed 66.66% male and 33.33% female.
The mean epithelialization time in this study was 3.7 weeks ±1.5 weeks. The purpose of this study was to evaluate the efficacy of amniotic membrane in the treatment of resistant corneal ulcer, patient satisfaction and the visual outcome.
We found that AM graft is useful in the treatment of resistant corneal ulcer with or without either descematocele or perforation. There was a significant improvement in the postoperative VA in this study. In addition, there was a significant reduction in postoperative anterior chamber reaction.
The surgical outcome was more favorable especially in cases without dry eye.
The overall success rate was 76.7%. from these results, it was concluded that AMT is useful in the treatment of resistant corneal ulcer due to many properties of AM such as:
• It is non- immunogenic tissue.
• It has bacteriostatic properties.
• It reduces angiogenesis.
• It inhibits fibroblast function by reducing scar formation.
• It prevents collagen degradation.
• It favors re-epitheliazation.
• It excludes inflammatory cells with anti-protease activities.