The amniotic membrane can be used in a large number of ophthalmologic surgical indications, either as graft, as coating, or a combination of both.
When implanted like a graft (or inlay technique) it fills out a defect by replacing the absent stromal matrix and providing a basement membrane that epithelization occurs on it. When applied like patch (or overlay technique) the amniotic membrane functions essentially as a cover protecting the ocular surface of possible external insults and providing biological substances that reduce inflammation and promote epithelial regeneration under the implant.
The surgical technique will vary in each case, depending on if it is used as a patch on its epithelial surface or as a graft on the stromal side (adherent). Theoretically, if stroma is directed towards the recipient the implant will incorporate, but if it is the epithelium/basement membrane of the amnion, should fall off. A single layer or multiple folded layers of amniotic membrane can also be applied. In the latter case, another layer of membrane is placed by coating the entire cornea.
Currently, amniotic membrane transplantation is a surgical procedure in expansion in which still there have been established neither the totality of its indications nor the different pathologies that can benefit from it.
In Human Ophthalmology has been used successfully to treat patients in cases of:
On the other hand, some restrictions on the use and effectiveness of amniotic membrane transplantation has also been described: with absence of tear, the transplantation may not restore the ocular surface; and in the presence of an important inflammatory reaction, the amniotic membrane can be quickly reabsorbed (both in case of graft as a patch).
In Veterinary Ophthalmology, there have been published different articles that value the use of amniotic membrane transplantation in cases of corneal ulcers, keratomalacia, dermoids, bullous keratopathy, corneal perforation and excision of corneal-limbal tumors in dogs and horses, or in cases of symblepharon and corneal sequestration in felines.