A common problem of animal eyes most common in dogs is keratoconjunctivitis sicca (KCS or "dry eye" syndrome). Some causes of “dry eye” include congenital disorders (puppies), surgical removal of the tear-producing gland of the third eyelid (“cherry eye”), administration of certain medications (e.g., sulfa antibiotics, Etogesic anti-inflammatory drug), and infections such as distemper. Most cases are considered “immune-mediated” and result from attack by the animal's own immune system on their own tear-producing glands. The disease is seen very commonly in certain breeds such as the Cocker Spaniel, Shih Tzu, Lhasa Apso, Bulldog, Schnauzer, and West Highland White Terrier.
The clinical signs of “dry eye” include large amounts of ocular discharge (that re-forms quickly after cleaning), redness of the eyes, rubbing at the eyes, cloudy eyes, and corneal ulcers. After an extended period of dryness, the surface of the eye (the cornea) begins to accumulate pigment and blood vessels. If this is allowed to progress, blindness can be the result! It is therefore important that the tear production be normalized rapidly.
Our treatment goals for KCS include stimulation of tear production, controlling secondary infections, and decreasing corneal scarring. Treatment is very effective if the condition is diagnosed early, but life-long treatment is usually required. The drug cyclosporine is anywhere from 50-90% effective in stimulating normal tear production in dogs, depending on the severity of the disease by the time of diagnosis. A newer KCS treatment, tacrolimus, is an option for severe cases including those where cyclosporine has failed. It is effective in some, but not all, of the cases where cyclosporine has failed. Cyclosporine and tacrolimus must be used as directed. If the medication is discontinued, the signs will usually recur. It can be more difficult, or impossible, to get controlled the next time around. It is very important to have your pet’s eyes periodically monitored in order to evaluate the success of treatment and to determine if any changes in treatment are required.