Dry Eye, also known as Keratoconjunctivitis sicca (KCS), is a disease in which the eye does not produce enough tears. It is very common in dogs and fairly uncommon in cats. Many breeds are predisposed to the disease, including: cocker spaniels, bloodhounds, Boston terriers, Cavalier King Charles spaniels, bulldogs, springer spaniels, West Highland white terriers, Lhasa apsos, miniature schnauzers, Pekingese, poodles, pugs, Samoyeds, Yorkshire terriers and shih tzus.
The normal tears produced for the eyes come from glands around the eye and in the eyelids. When these glands fail to function normally or are damaged, the resultant lack of tears causes irritation to the eye. Oftentimes owners will notice a thick, often ropey discharge from the eye that sticks to the eye surface or crusting of discharge on the pets’ eyelids. Usually there is redness or irritation seen and the pet may squint or blink more frequently than normal and even rub at their face. In most cases, dry eye is an on-going problem that the pet will have the remainder of their life.
Most pets will usually have both eyes affected. If only one eye is affected initially, the disease process usually starts in the other soon after. With continued maintenance care, the disease can usually be managed quite well. If not treated, dry eye can result in discomfort and pain and has the potential to lead to blindness.
Dry eye has many different inciting causes. These include: drug induced (including some oral antibiotics and anti-inflammatories), surgically induced (after removal of the gland of the third eyelid to correct a prolapse, also known as “cherry eye”), immune mediated (when the body mistakenly believes the tear glands are foreign and attacks them), trauma, infections, poisonings, and hormonal among others.
The most common cause of dry eye in the dog is immune-mediated.
The diagnosis of dry eye is based history, signs and symptoms, physical exam findings and testing. The Schirmer tear test is simple test that allows us to determine the eye’s tear production. This test involves placing a specially marked absorbent strip against the eye for a specific amount of time. The result allows us to determine if the tear production is adequate. Another test that may be performed is the fluorescein dye test. This test is done anytime there is a concern that the cornea (the outer clear portion of the eye) may have an ulcer on it. A green dye is applied to the eye and if an ulcer is present, the dye will adhere to it, making it readily visible. It is important to know if an ulcer is present on the eye as additional treatments are needed to help resolve this. Blood tests may also be necessary to check for systemic problems such as low thyroid levels.
It is important that the eyes be cleaned of discharge on a daily basis. This is best accomplished with a sterile eye wash and gently wiping of the eyes with soft gauze, cotton ball or tissue. Initial medical therapy will usually involve medication in the form of drops or ointment. The most common medication used to treat dry eye is cyclosporine. It works in several different ways to help stimulate the body’s normal tear production. Initially it is usually administered twice a day and it can take several months before a significant increase in tear production is noted. In many cases, once tear production has improved, the cyclosporine frequency can be reduced to once a day. Wetting agents, such as artificial tears, play an important role in helping to keep the eye moist while waiting for tear stimulants to take effect or in cases where tear production remains inadequate. It is often recommended that these agents be used several times throughout the day. Other eye medications may be used depending upon the response to therapy and if any secondary conditions, such as a corneal ulcer or infection, are present. In rare cases, surgery may be recommended. This procedure moves a salivary gland duct to open into the eye sac to provide substitute lubrication. Even if successful, it rarely eliminates the need to treat the eye topically.
Follow-up visits are required to monitor the response to the medication and to evaluate for any other problems that may arise. In many cases, the number and frequency of medications may be reduced but almost all patients will require some level of treatment for life.
•Follow instructions regarding medication and recheck appointments. If you are applying many different medications to the eyes several times per day, it may be helpful to prepare a chart to keep track of treatments. •Note any changes in eye color, redness, corneal cloudiness, or comfort level and contact us if any of these occur. •If the treatment schedule involves more than one medication, try to wait at least 5 minutes between medications. Try to apply drops before apply ointments. •Clean eyes daily using a sterile eye wash solution. Removing the discharge will help the medication work better and keep the eye more comfortable. •Realize that with a good response to treatment, normal tear production can return, but that maintaining this tear production usually requires ongoing daily treatment.
•Do not ignore any changes in your dog’s eyes. Some complications can occur quickly, such as corneal ulcers, and mild changes such as reddening of the whites of the eyes may be the first sign you see that indicates a problem. •Do not stop administering medications just because the eyes looks better. A relapse can occur easily if medications are decreased or stopped.
When to Give Us a Call
•If you are unable to give or administer any medication prescribed as directed. •If you note any worsening of signs or symptoms as listed below.
Signs to Watch For
•Monitor your dog for any signs or subtle changes such as: oRedness, squinting of the eyes. oRecurrent (day after day) thick, yellow or green discharge accumulating in the corners of the eyes or even directly on the surface of the eyes, often worse in the morning. oLoss of vision.
•Follow up appointments will be necessary after KCS is confirmed. At first, these may be frequent, in order to make sure the medications are working and the disease progression is stabilized. •The frequency of the appointments will depend on the severity of the disease and the response to therapy.