Eosinophilic Keratitis

a condition in which the cornea becomes infiltrated with eosinophils and other types of inflammatory cells

What is it?
Eosinophilic keratitis is a condition in which the cornea (the clear front part of the eye) becomes infiltrated with eosinophils (a type of white blood cell) and other types of inflammatory cells.

What causes it?
The cause of the eosinophilic keratitis is often multifactorial, but in many cases feline herpesvirus infection is the underlying cause.  Occasionally, the immune-system of the eye surface is over-stimulated for an unknown reason, which also results in this condition.  Many conditions caused by feline herpesvirus can be chronic and recurrent.

What are the symptoms?
Initially, the conjunctiva will be reddened. In the next stage of the disease, white deposits develop on the cornea.  Finally, the cornea turns pink or red and a white plaque develops.

Who is susceptible?
This disease is feline specific.

How is it diagnosed?
Diagnosis is based primarily on the presence of corneal lesions.

How is it treated?
Treatment includes topical ant-inflammatory medications such as cortisone (steroids) or cyclosporine.  Topical anti-viral medications are also often prescribed.  Injectable cortisone may be recommended for severely affected eyes.  Complete resolution of signs can take a few weeks.  Medications are reduced slowly over a period of several more weeks to minimize the risk of recurrence.  However, recurrence does occur in some patients and low frequency, maintenance treatment may be warranted in order to maintain comfort and vision long term.