Dry eye is a condition in which the tear glands are unable to provide adequate moisture to the eye. Each eye has two tear glands, one is located above the eye within the orbit and another, smaller gland is associated with the third eyelid. While this can occasionally be caused by trauma, hypothyroidism, or a drug reaction, most cases are inherited or due to unknown causes. The condition usually affects both eyes, is chronic, and requires management for the duration of the dog’s life to prevent discomfort and loss of vision associated with scarring of the surface of the eye. Dogs with this condition are also more susceptible to eye infections which can complicate treatment. Symptoms include redness, a thick discharge from the eyes and, with time, cloudiness and loss of vision.
Treatment for “dry eye” may be either medical or surgical. Fortunately, most animals respond well to medical therapy, designed to stimulate the tear gland to produce more tears. Cyclosporine is the name of the medication which is most commonly used twice daily. Removal of discharge from the eyes is also very important as it can serve as a medium for bacterial growth. An eye wash is recommended to irrigate the surface of the eyes. Do not use water or wipe the eyes with a tissue to remove the discharge. Topical antibiotic ointments are often necessary to prevent recurrent bacterial infections. All medications must be applied on a regular schedule to prevent progression of the symptoms and potential vision loss. You may continue to refill the medications until your pet is due for the next recommended re-examination. If your pet ever requires oral antibiotics for other problems, sulfa medications should not be used as they can further decrease tear production.
Surgery may be necessary in rare cases where the tear glands are unable to respond to medication. The surgical procedure involves moving a salivary gland duct from the mouth to the eye (parotid duct transposition) to provide a constant source of moisture to the eye. The procedure is very successful in keeping the eye moist but it does not entirely eliminate the need for continued medication. After surgery, the operated eye appears to “tear” while the dog is eating because of stimulation to the salivary gland and it may be necessary to clean and dry the face after mealtime.