If your pet is squinting, has eye discharge, or has a significantly swollen eye, these are considered a “YELLOW” – or semi-urgent case – on our Fast Track Triage system. We recommend having your pet evaluated by your family veterinarian, a board-certified veterinary ophthalmologist, or local animal emergency hospital within 24 hours. Call ahead of your arrival so the veterinary team knows to expect you, and if your pet’s condition worsens, call the team back to inform them of the status change.
Tears are an important part of vision and eye protection – for humans & pets! The tear film improves vision, lubricates the ocular surface, provides comfort, removes debris, and helps to reduce the risk of infection. The tear film is made up of three layers including an outer oily layer, middle liquid layer, and inner mucus layer. A lack of the liquid (aqueous) portion of the tear film is called Keratoconjunctivitis Sicca (KCS), also known as quantitative “dry eye”. Loss of the thin outer lipid layer results in premature evaporation of the tear film which causes symptoms of dry eye called qualitative dry eye syndrome. If your pet is experiencing decreased tear production or poor tear film quality, here’s what you need to know about the causes, symptoms, diagnosis, and treatment of dry eye.
Causes of Dry Eye
The most common cause of dry eye is autoimmune destruction of the tear-producing lacrimal gland. This condition is similar to Sjogren’s syndrome in people. Fortunately, this immune condition is limited only to the tear-producing gland of the eye and no other parts of the body are affected. Often, dry eye occurs in middle-aged or older dogs. Any breed can be affected.
Other less common causes of dry eye include neurologic dysfunction, lack of tear gland development, prior removal of the third eyelid gland, use of a sulfa-based antibiotics, and other causes.
Signs to Look For
The severity of dry eye symptoms is highly variable between patients based on their level of tear production. Pet owners should watch for the following signs of dry eye:
- Squinting
- Rubbing
- Redness
- White to yellow mucous ocular discharge
- Cloudiness or redness of the eye surface
Note: Corneal ulcers may develop secondary to dry eye.
Diagnosing Dry Eye
Dry eye is diagnosed based on your pet’s history, clinical signs, and diagnostic test results, such as:
- Schirmer Tear Test (STT)
- This primary diagnostic test involves applying specialized paper strips to the eye surface for one minute to allow for evaluation of the tear film quantity.
- Dogs that produce tear values less than 15 millimeters in one minute are diagnosed with dry eye.
- Fluorescein Stain
- This bright green stain is used to evaluate the rate of tear film breakup and identify corneal ulcers.
- Cytology or Culture of the Ocular Surface
- These tests may be recommended in some instances when eye infections are suspected.
Treatment
There are multiple treatment options for dry eye, including:
- Cyclosporine (Optimmune®) and Tacrolimus
- These medications both reduce inflammation of a pet’s tear glands and directly stimulate tear production.
- Both drugs must be used for your pet’s entire life.
- Topical drops or ointments are the most common form of treatment; however, long-acting cyclosporine implants may be recommended by your veterinary ophthalmologist.
- Topical Anti-Inflammatory Steroid Medication
- Your pet’s ophthalmologist may prescribe topical steroids to reduce inflammation and scarring of the eye surfaces.
- Artificial Tear Preparations
- These are used to provide lubrication to the cornea pending improved tear production.
- Purified Water Eye Wash Solutions
- These can also be used to clean mucous and debris from the eye prior to applying topical medications.
- Specific Therapies
- There are specific therapies for less common forms of dry eye. Your pet’s ophthalmologist can discuss further information and treatment options if your pet has been diagnosed with one of these uncommon variants.
Most dogs diagnosed with dry eye respond well to topical medical therapy. Typically, life-long medication administration is required for this condition. Your pet’s ophthalmologist will work with you and your pet to find the medication combination that best controls your pet’s clinical signs.
If you have any questions or concerns about your pet’s ocular health, talk to your family veterinarian or ask for a referral to our Ophthalmology Service.
