Feline Eosinophilic Keratitis
Eosinophilic keratitis is associated with infiltration of eosinophils into the feline cornea. It may be an unusual immune response to latent feline herpesvirus. Treatment with topical steroids usually is sufficient, but some cases do not respond. Oral megestrol acetate (0.5 mg/kg, sid until a response is noted, then 1.25 mg, PO, 2–3 times weekly as required) helps to improve or resolve the corneal inflammation via an unknown mechanism. However, its use is associated with adverse effects such as diabetes mellitus, adrenocortical suppression, and uterine hyperplasia, and this drug should be used with extreme caution. Megestrol acetate can also be dangerous to women handling the pills.
Feline Hypertensive Retinopathy
Older cats can present with sudden blindness due to serous retinal detachments secondary to systemic hypertension. Treatment is with the calcium channel blocker amlodipine (0.625 mg/cat) and systemic corticosteroids (prednisone, 0.5–1 mg/kg, PO) to help control the posterior inflammation. Retinas will reattach once blood pressure returns to the normal range. At least 50% of cats will regain some clinical vision if treated early.
Last full review/revision March 2012 by Nick Whelan, BSc, BVSc, MVSc, MACVSc, DACVCP, DACVO