Amniotic membrane in ophthalmology: properties, preparation, storage and indications for grafting—a review

Abstract

The use of amniotic membrane in ophthalmic surgery and other surgical procedures in the fields of dermatology, plastic surgery, genitourinary medicine and otolaryngology is on the increase. Furthermore, amniotic membrane and its epithelial and mesenchymal cells have broad use in regenerative medicine and hold great promise in anticancer treatment. Amniotic membrane is a rich source of biologically active factors and as such, promotes healing and acts as an effective material for wound dressing. Amniotic membrane supports epithelialization and exhibits anti-fibrotic, anti-inflammatory, anti-angiogenic and anti-microbial features. Placentas utilised in the preparation of amniotic membrane are retrieved from donors undergoing elective caesarean section. Maternal blood must undergo serological screening at the time of donation and, in the absence of advanced diagnostic testing techniques, 6 months postpartum in order to cover the time window for the potential transmission of communicable diseases. Amniotic membrane is prepared by blunt dissection under strict aseptic conditions, then is typically transferred onto a nitrocellulose paper carrier, usually with the epithelial side up, and cut into multiple pieces of different dimensions. Amniotic membrane can be stored under various conditions, most often cryopreserved in glycerol or dimethyl sulfoxide or their mixture with culture medium or buffers. Other preservation methods include lyophilisation and air-drying. In ophthalmology, amniotic membrane is increasingly used for ocular surface reconstruction, including the treatment of persistent epithelial defects and non-healing corneal ulcers, corneal perforations and descemetoceles, bullous keratopathy, as well as corneal disorders with associated limbal stem cell deficiency, pterygium, conjunctival reconstruction, corneoscleral melts and perforations, and glaucoma surgeries.

Effect of the Use of the Human Amniotic Membrane in Healing of Surgically Induced Skin Defects in Rabbits (Histopathological Study)

“…The clinical manifestations of the present study revealed the absence of abnormal movements and signs of discomfort expressed by rabbits while changing the dressing at the AM grafted sites, this confirms the pain reduction property of the amniotic membrane. Many studies revealed a rapid pain relief when using AM over burns (10), chronic ulcers (19), symptomatic bullous keratopathy and ocular Band keratopathy (20). Although one may attribute AM's effect in relieving pain to its anti-inflammatory antibacterial action and its adherence to wound covering the nerve endings, we suspect that such a rapid action in pain relief may due unknown anti-pain action that deserves further investigation.…”

“…It has been demonstrated that the AM speed up the maturation of keratinocytes and epithelialization process. Beside acting as a scaffold for epithelial cell migration and support the basal epithelial cells, AM contains various growth factors that stimulate epithelialization, promote epithelial differentiation and prevent its apoptosis (20,21). These findings evaluated by the significant difference in epithelial thickness between both grafted and non-grafted wound in last two weeks.…”

Preparation of placental tissue transplants and their application in skin wound healing and chosen skin bullous diseases ‐ Stevens‐Johnson syndrome and toxic epidermal necrolysis treatment

“…7,[59][60][61] Amniotic membrane is commonly used with very good clinical effects in eye ulcerations, eye burns or corneal epithelial defects. [62][63][64][65] Moreover, its high efficacy was shown in patients after pterygium extended removal. This surgical removal was followed by fibrin glue-assisted amniotic membrane transplantation, which resulted in low complication rate, low recurrence rate and high cosmetic satisfaction found during postoperative follow up.…”

Ophthalmic use of amniotic membrane tissue in Australia: Introduction and initial use of a service

“…Amniotic membrane (AM) has been used across ophthalmology for almost 80 years . AM has been shown to stimulate wound repair while suppressing inflammation, angiogenesis and scarring offering potential opportunities for the successful treatment of an increasing number of ophthalmic indications . Essential for use in ocular surgery, the tissue is non‐reactive and largely transparent .…”