Veterinary care should include diagnostic tests and subsequent treatment recommendations.
Diagnosis In-depth Your veterinarian will perform a thorough examination of the eye and structures around the eye. Careful examination of the cornea under magnification is necessary to identify adhesions between iris and cornea, to diagnose harmless pigmentation, or to recognize a corneal scar. Examination of the structures within the eye may reveal the presence of an iris cyst. The eyelids are examined for foreign bodies, abnormal eyelashes and the position of the eyelids needs to be evaluated. In some cats, entropion (inward rolling of the eyelids) may cause chronic irritation of the cornea with secondary sequestrum formation. In cats that are severely painful, application of a topical anesthetic solution allows better examination of the eye.
Fluorescein stain is applied to the eye to determine if corneal ulceration is present. An ulcer may or may not be present in the area of the sequestrum.
The tear production is measured using a Schirmer tear test to check for inadequate tear production (dry eye).
A test for feline herpesvirus (IFA or PCR) may be performed.
Your veterinarian may recommend referral to a veterinary ophthalmologist for further evaluation and treatment.
There are two general methods of treating a corneal sequestrum. One method employs the body's ability to reject dead tissue while protecting the eye with medication. The other method is surgical removal of the diseased tissue.
The eye is treated with an antibiotic solution or ointment three to four times a day. Atropine ointment is sometimes used to relieve pain when the pupil has become very small and spastic, but it may, in some cats, cause severe drooling. This effect is more commonly seen with atropine drops than with atropine ointment.
Medical management allows the body time to remove the sequestrum. The purpose of the medication is to prevent secondary bacterial infections while the body removes the sequestrum. Blood vessels will grow into the cornea and will eventually grow under the sequestrum and remove the sequestrum from the cornea. This entire process may take many months to complete.
Surgical treatment consists of careful removal of the affected layers of the cornea. In some cats, the sequestrum involves both superficial and deep layers of the cornea, making conjunctival or corneal grafting procedures necessary after removal of the lesion. Aftercare consists of topical antibiotic solution of ointment, with or without atropine, for a few weeks while the surgery site heals. The advantage of surgery is quicker resolution of the problem and return of the cat to a pain-free state.
A sequestrum may recur after it has either been allowed to slough using medical management or after it has been surgically removed. There is some evidence that suggests that recurrence is less likely if the entire lesion is surgically removed, and all abnormal tissue is successfully removed from the cornea.