Keratoconjunctivitis Sicca (KCS) - Dry Eye

Dear Dr Jody:  Recently, our 5 year old pug, “Porkchop”, has been rubbing at his right eye.  In the morning, there is a lot of crusty material and discharge that we have to clean away from his eye.  He seems very uncomfortable.  What can we do to help?

Ah yes, pugs and their eyes.  Pugs are great little dogs but they certainly are predisposed to a myriad of eye problems.  Because pugs are exophthalmic, meaning their eyes bulge, their eyes are much more likely to become damaged.  In some pugs, the eyes bulge so much that the eyelids do not ever close completely with each blink of the eye.  This anomaly is imperceptible to an observer but can lead to chronic uncomfortable changes to the cornea.

It is possible that Porkchop is suffering from a condition known as Keratoconjunctivitis Sicca (KCS).  KCS is characterized by a deficiency of the watery portion of the tears.  The eye becomes irritated by this lack of moisture and tries to compensate by overproducing the mucoid part of the tears, leading to excessive “goop” in the eye that must be cleaned away frequently.  Not only is this condition painful, it can predispose the dog to a host of other ailments, including corneal ulcers, bacterial infections of the eye, and even blindness.

In order to make a diagnosis in Porkchop, your veterinarian will do a thorough physical exam, paying special attention to the eyes.  He or she will perform a number of painless eye tests, including a Schirmer tear test, a fluorescein stain, and tonometry.  The Schirmer tear test involves tucking a small, thin strip of paper just under the lower eyelid.  Your vet will measure how far down the strip of paper your dog’s tears are able to wick in 60 seconds.  If Porkchop’s tears are not able to advance more than 15 mm down the piece of paper, he likely has KCS.  A second test is used to rule out corneal ulcers, which are common side effects of KCS.  A drop of fluorescein stain is applied to the surface of the eye.  This green dye has an affinity for areas of damaged cornea, and will stick to these ulcerated areas.  A black light is then used to examine the eye for areas of fluorescence.  Areas that glow bright green can indicate painful defects to the cornea that require medical (and sometimes surgical) treatment.  Finally, your vet will want to ensure that Porkchop does not have glaucoma.  Just as your ophthalmologist will have you look into a special machine that blows a startling puff of air onto your eye, Porkchop will undergo a similar test that painlessly measures his intraocular pressure (IOP).  Elevated IOP is referred to as glaucoma, and requires medical treatment to alleviate discomfort, reverse the condition, and preserve vision.

If your vet diagnoses Porkchop with KCS, rest assured that there are treatments that can make his eyes dramatically more comfortable.  Unfortunately, most cases of KCS require lifelong daily treatment in order to effectively manage the symptoms.  Please consult your veterinary  health care team immediately if you are concerned that your pet’s eyes may be troubling him.