A corneal ulcer refers to an abraded area on the cornea. There are different classifications of ulceration depending upon the depth of the ulcer itself.

The majority of corneal ulcers are very superficial and only affect the top corneal layer. Some causes for superficial ulcers are:

Self-trauma (scratching at the eye)

Tear film disorders such as dry eye

Eyelid structure/function abnormalities

Minor trauma


Irritation from stray hairs

Globe anatomy (“bug eyes”, etc.)

Foreign bodies (weed awn behind the 3rd eyelid)

Deeper corneal ulcers affect multiple layers of the cornea and generally are harder to resolve. These may be due to progressive superficial ulcers, moderate/severe trauma, etc.

Indolent ulcers are a type of corneal ulcer that occurs when the “new” superficial layer of the cornea doesn’t adhere to the underlying layers making it impossible for the body to repair the defect. Many indolent ulcers are breed-related. Boxers tend to be predisposed to this type of ulcer. Indolent ulcers can also occur as a result of a progressive superficial ulcer.

Clinical Signs




Conjunctivitis (redness in the whites of the eye and

inner eyelids)

+/- Cloudy cornea


Diagnosing a corneal ulcer is typically straightforward. Stain is placed in the eye. The stain is only taken up in areas where the top corneal layer is absent (only in the ulcerated areas). In some deep corneal ulcers the stain uptake is more elusive and may require further diagnostics. An eye pressure may be taken to rule out uveitis (inflammation in the front chamber of the eye) or glaucoma.


The treatment for corneal ulcers varies depending upon the type, severity and secondary signs associated with it. Corneal ulcers in general cause a great deal of discomfort, as the cornea has a large number of nerve endings.

Superficial Ulcers

These ulcers are the easiest to treat and typically resolve

with an antibiotic ointment or drops. If there is associated uveitis atropine ointment may also be used for pain.

The antibiotic ointment is to be applied 3-4 times daily.

Artificial tears or cyclosporine ophthalmic preparation may

also be indicated if underlying dry eye is the cause of the ulceration.

The majority of superficial ulcers are healed within

7-10 days.

Deep Ulceration

Deep ulcers may initially be treated the same as

superficial ulcers but may require more lengthy therapy, additional medications, and/or surgical intervention.

Animals with deep ulceration often need some type of

protection for the eye and a conjunctival or 3rd eyelid flap may be used. These flaps provide moisture and protection for the damaged tissue.

These ulcers may progress to indolent ulcers and are

treated as outlined below.

Depending upon the case, a referral to a veterinary

ophthalmologist may be recommended.

Indolent Ulcers

Indolent ulcers require the most attention and aggressive

treatment. Depending upon the severity, initially antibiotic preparations and atropine are used. Non-adherent corneal tissue is usually manually debrided with a cotton swab under local anesthetic. If this procedure is not successful a grid keratectomy is indicated.

A grid keratectomy is performed under general anesthesia.

A grid of superficial lines is etched into the corneal surface to provide a stable framework for new healthy tissue to cover the defect.

Depending upon the case, a referral to a veterinary

ophthalmologist may be recommended.

In general, corneal ulcers require repeat visits to monitor the healing process through multiple eye stainings and topical medications.

Corneal ulcers can be a serious problem and may result in blindness if not treated. Uncommonly, an ulcer may progress to the point that the eyecannot be saved.

This is a rare occurrence, but all the more reason to be diligent with the treatment plan.




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