The cornea is covered by a protective surface layer of epithelial cells. Any irritation, such as a scratch or foreign body, damages this surface layer. Swelling at the site of the injury, as well as edema, causes the area to appear hazy and opaque when viewed under magnification. The opaque area also stains positive with fluorescein dye.
Corneal abrasions in the upper part of the cornea may be caused by misdirected eyelashes. Lower corneal opacities suggest an imbedded foreign body. Abrasions near the inner corner of the eye suggest a foreign body beneath the third eyelid.
A corneal abrasion usually heals in about three to five days by a process in which the adjacent epithelial cells enlarge and migrate over the defect. The injury will not heal, however, if a foreign body is imbedded in the cornea or beneath one of the eyelids. It is important to check for a foreign body in all cases of corneal abrasion.
Corneal abrasions and ulcers are diagnosed using a special fluorescein dye that is applied to the eye. Damaged tissues will pick up the dye.
Treatment: All corneal injuries must be seen and treated by a veterinarian to avoid complications, including keratitis and corneal ulcer. Broad-spectrum topical antibiotic drops or ointments are prescribed every four to six hours to prevent infection.
A topical atropine preparation is used to keep the pupil dilated, which reduces eye pain. Keep your dog out of bright light, including bright sunlight, when the pupil is dilated. The atropine has a bad taste and many dogs will foam at the mouth if they get some in their mouths while you are medicating them. This will pass in a minute or two.
The eye is examined periodically to monitor progress. Treatment is continued until the abrasion is healed.