Keratoconjunctivitis Sicca (KCS)
Keratoconjunctivitis sicca (KCS) is sometimes called “dry eye”. It is a condition in which tear production is decreased or sometimes even totally absent. This causes the outer layer of the eye (cornea) to dry out and become painful.
Loss of vision can result.
Causes Of Keratoconjunctivitis Sicca:
Tears are produced from 2 major sources:
- Tear glands positioned above each eyeball, and
- Accessory glands distributed throughout the front of the eyes, including the eyelids.
Inflammation or destruction of these tear glands can reduce tear production to such a low level that the eye begins to dry out.
Causes of this condition include trauma, drug toxicities, chemical irritations, viral infections, tumors, nerve degeneration, congenital defects where the dog is born without well-formed tear glands, and autoimmune reactions.
In most cases, the exact cause cannot be determined. There is evidence that up to 90% of KCS cases are related to a problem with the dog’s immune system. The role of the immune system is to protect against disease. In certain instances, the dogs own immune system can mistakenly recognize parts of its own body as foreign invaders and set out to destroy them.
In KCS, it is thought that the immune system may actually destroy the glands that are responsible for tear production, leaving the dog incapable of producing sufficient tears.
Symptoms Of Keratoconjunctivitis Sicca:
Clinical signs include
- frequent accumulation of mucus in the corners of the eye,
- reddened eyes,
- dry and dull cornea,
- squinting and rubbing the eyes,
- loss of transparency in the cornea, and
- possibly the presence of ulcers on the corneal.
Diagnosis Of Keratoconjunctivitis Sicca:
Diagnosis is based on clinical signs and results of the Schirmer tear test. This test involves placing a special strip of paper over the dog’s lower eyelid. After one minute, the amount of moisture absorbed by the special paper is measured and the results compared to known standards.
It may also be necessary for your dog's veterinarian to apply a special dye to your dog's eye to detect the presence of corneal injuries resulting from the "dry eye".
Your dog's veterinarian will also examine the interior of the eye and assess the degree of scarring and damage present in the cornea (the front part of the eye).
Treatment Of Keratoconjunctivitis Sicca:
KCS cannot be cured. However, it is very easily treated and controlled in most dogs. Your veterinarian will determine the most appropriate medication for your dog. Likely, it will involve ointments applied to your dog's eyes on a regular basis.
Cyclosporine ointment is the most frequently used medication in treating keratoconjunctivitis sicca.
Artificial tear ointments and solutions are also recommended frequently.
In addition, antibiotic ointments or drops may be necessary if there is corneal damage present.
If inflammation is present, cortisone ointments or drops may be necessary and are frequently combined with antibiotic ointments and/or drops.
Keeping the eyes clean and free of discharge is also an important part of caring for animals suffering from keratoconjunctivitis sicca. Your dog may need to have the eyes cleaned regularly with an eye irrigation solution.
If the discharge is sticky and difficult to remove, soaking the area with warm water or applying a warm compress to the area for a few moments may help loosen up the debris and make it easier to remove.
