We first saw Belle with a very large corneal ulcer in the middle of her right eye. The cornea is the transparent layer at the front of the eye and an ulcer is damage to the outside surface of this layer. The dog cornea is only about 0.6mm thick so any damage to the cornea that is deep or ‘melts’ (gets deeper with time) runs the risk of the eye perforating. Belle’s ulcer was large to start with and did not heal well, leading eventually to a hole forming in the cornea and the contents of the eye starting to leak out. If left untreated this would result in a collapsed, blind eye and the eye would have to be removed.
We admitted Belle for emergency surgery to repair her cornea and save her eye. This was done via a conjunctival pedicle graft: a strip of conjunctiva (the pink lining between the eyeball and the eyelid) from the above the cornea is created and whilst still attached to its source at one end is then sutured to the healthy cornea around the ulcer. This piece of conjunctiva has its own blood supply (which the failing ulcer does not) and hence the healing is enhanced. The conjunctiva attaches to the cornea, plugs the hole and fills the deficit that was the ulcer. Once healing is complete, the bridge of conjunctiva that provides the blood supply from above the cornea is cut, leaving a little island of conjunctiva growing in the cornea. Over time this is incorporated into the cornea leaving only some scarring, but an otherwise fully functional and comfortable eye.