AmnioGuard is an umbilical cord graft used by Oculoplastic surgeons for several indications. Due to its high tensile strength and thickness, AmnioGuard is easy to handle and suture and can be used for corneal, conjunctival, sclera, fornix, socket, and eyelid reconstruction.
Created using the Company’s proprietary CryoTek® cryopreservation method, AmnioGuard delivers the natural properties of the amniotic membrane to help reduce inflammation, scarring and promote regenerative healing. AmnioGuard is a resilient and single-layer tissue which provides strong tectonic support for treating corneal, scleral, socket, fornix, and eyelid problems. For example, when it is used to cover the glaucoma shunt tube, it also allows visualization of the shunt tube and laser suture lysis and better cosmesis.
AmnioGuard is minimally manipulated tissue, which contains naturally-occurring biological factors that have been recognized as suppressing inflammation, preventing scar, and promoting ocular surface healing. The cryopreserved umbilical cord was developed to cover a wide variety of drainage devices to ensure superior surgical outcomes. AmnioGuard exerts anti-inflammatory and anti-scarring actions and works synergistically with a patient’s own system to enhance and speed tissue repair, resulting in a calm, white eye with minimal discomfort.
High tensile strength and thick umbilical cord grafts for extra tectonic support.
Average thickness: 500-900 μm19
AmnioGuard is a beneficial alternative to other commonly used grafts. However, it could be used in combination with a mucosal graft to deliver a premium outcome. In contrast to Autograft such as mucosal graft, other allografts available are dehydrated in nature and don’t retain the tensile strength and many of the key biologics responsible for facilitating healing.
Yes, like AmnioGraft, AmnioGuard delivers both biologics (HC-HA/PTX3) while functioning as a surgical graft into which host cells migrate to repair the damaged tissue. However, AmnioGuard is an excellent alternative when a thicker graft is required and tectonic support is necessary, especially in cases when patients present with deeper defects such as descemetoceles, perforations, and scleral melts. The thickness and tectonic strength of AmnioGuard allows the surgeon to suture without folding, dislocation, or dehiscence of the graft with no corneal leakage.
Yes. The fetal origin of the umbilical cord makes it immune-privileged, driving a more rapid and more efficient immune response. It also averts the possible immune-related graft melting and promotes improved host-tissue integration to prolong graft survival.
Oral mucosal grafts result in discomfort in the mouth during the healing period, unsatisfactory cosmetic results in the eye, and may mask tumor recurrence because of the non-conjunctival epithelial morphology. However, AmnioGuard is commonly used in conjunctival reconstruction to facilitate healing with less inflammation and minimal scarring. CryoTek® preserves the intact basement membrane and contains a higher amount of soluble, inflammation modulating factors. AmnioGuard facilitates complete epithelial healing, with excellent cosmesis in all patients.
The increased thickness of the AmnioGuard replaces the full thickness of the excised conjunctiva and episcleral making it an excellent choice for a graft post tumor excision in deeper wounds. Despite its thickness, AmnioGuard did not contribute to Dellen formation. No complaints of discomfort, failure, dehiscence, or infection.
AmnioGuard can be either sutured (using an 8-0 Vicryl suture) or glued (fibrin glue), or both to the surrounding conjunctiva and underlying sclera. Fibrin glue can shorten the surgery time and decrease conjunctival inflammation and discomfort.
AmnioGuard is a viable alternative for conjunctival surface reconstruction after the excision of tumors due to its thickness, post-operative outcomes (function & cosmesis), ease of handling, and cost-effectiveness.
The disadvantages of autologous substitute grafts include an undesirable cosmetic appearance, foul discharge, graft harvesting, donor-site morbidity, and contraction of the graft.
AmnioGuard is available in three sizes:
References:
1. Finger PT, Jain P, Mukkamala SK. Super-thick amniotic membrane for ocular surface reconstruction. Am J Opthalmol. 2019;198:45-53.
2. Sheha H, Tello C, Al-Aswad L, Sayed M, Lee R. Outcomes of the shunt tube exposure prevention study (STEPS), a randomized clinical trial. Opthalmol Glaucoma. [Online] August 16, 2019.
3. Slentz D, Nelson C. Novel use of cryopreserved ultra-thick human amniotic membrane for management of anophthalmic socket contracture. Ophthalmic Plastic Reconstr Surg. 2019;35(2):193196.
4. Slentz D, Joseph S, Nelson C. The use of umbilical amnion for conjunctival socket, fornix, and eyelid margin reconstruction. Ophthalmic Plast Reconstr Surg. 2019. doi: 10.1097/ IOP.0000000000001555
5. Tan EK, Cooke M, Mandrycky C, et al. Structural and biological comparison of cryopreserved and fresh amniotic membrane tissues. J Biomater Tissue Eng. 2014;4(5):379-388.