While superficial corneal ulcers can often heal with medical treatment alone, in some cases the defect is too deep and/or the edges are unstable and the integrity of the cornea is at risk.
In these cases, and when the cornea has already perforated, corneal grafts become essential to repair the cornea and prevent leakage of the intraocular contents and ultimately the loss of the eye.
All types of grafts are performed with the help of an operating microscope using corneal microsurgery instruments and fine 8/0 or 9/0 absorbable sutures.
Common reasons for corneal grafts in small animals include:
- Stromal Ulcers: Deep and/or infected stromal ulcers can put the eye at risk of rupture or further infection. Grafts help to stabilise the cornea while it heals.
- Corneal Perforation: When the cornea perforates, grafts become indispensable to prevent the loss of the eye.
- Feline corneal sequestrum – following the removal of deep sequestra grafts offer tectonic support to the healing cornea and help prevent the formation of new sequestra.
- Chronic corneal oedema associated with endothelial degeneration: in these cases, thin vascular grafts are sutured over the oedematous cornea to help drain out the excess fluid.
- Epibulbar melanoma: since epibulbar melanomas are typically quite deep-seated, grafts are often necessary to fill the defect that results from their surgical excision.
There are three primary types of grafts used for this purpose:
- Corneo-Conjunctival Transposition (CCT) grafts: These grafts involve using a healthy section of the patient’s own cornea for repair.
- Conjunctival Pedicle grafts: These grafts are harvested from the conjunctiva, which is the membrane that covers the white part of the eye.
- Xenografts: These are grafts composed of tissues not originating from the patient. Examples include Biosis grafts, made from porcine intestinal submucosa, Acell grafts, made from porcine bladder submucosa, Biocornea grafts, made from porcine cornea, and amniografts, made from human amniotic membrane.
