THE cornea is the transparent shiny membrane which acts like a window for the front of the eyeball.
A corneal ulcer occurs when there is damage to the layers of the cornea.
These ulcers can range in severity from those just affecting the superficial layers, to ulcers which extend right through to the deepest layers of the cornea.
Corneal ulcers can affect cats, dogs, horses and cattle.
If left untreated, corneal ulcers can potentially cause the eye to rupture, where irreparable damage and blindness can occur.
The most common causes of corneal ulcers are due to traumatic injuries such as abrasions or cat scratches.
Other causes include irritation from eyelid abnormalities, grass seeds, decreased tear production, problems with the eye blinking, or infectious causes.
Corneal ulcers are painful, so signs to look out for are: squinting, rubbing of the eyes, discharge from the eye, or the animal avoiding bright light.
A veterinarian can diagnose corneal ulcers by closely examining the eye and with the use of a fluorescent green stain.
If an ulcer is present, it will soak up the stain and fluoresce under UV light.
However, this staining technique is not very effective for deep ulcers.
Once a diagnosis of a corneal ulcer is made, the treatment will depend on the severity of the ulcer.
Superficial ulcers will usually heal by themselves, with a vet prescribing antibiotic ointment to prevent any further infection whilst healing takes place.
Regular re-visits to the clinic will be required to monitor the eye during this time.
Complicated or deep ulcers may require surgery to help the healing process, this sometimes requires referral to a specialist.
Corneal ulcers can deteriorate quickly, so it is very important that you have your vet examine any eye problems early with your pet.
Some medications can even make corneal ulcers worse, so it is not recommended to treat eye problems at home but rather consult with your local veterinarian.
Alistair Chatto, veterinarian