What is Macropalpebral Fissure Syndrome in Dogs?

A year after Frank and Lynda lost their beloved chocolate Lab to cancer, they decided to adopt a dog from a local rescue. It was love at first sight when they spotted a two-year-old Pekingese named Lulu. However, they got bad news when they took their new best friend to the vet for a checkup. The vet suspected the dog suffered from macropalpebral fissure syndrome and made a referral to a veterinary ophthalmologist.

Definition

According to a paper presented at a symposium co-sponsored by The Ohio State University College of Veterinary Medicine, micropalpebral fissure syndrome in dogs is a genetic condition usually associated with other congenital defects like microphthalmos (one or both eyes are abnormally small).

This disorder is associated breeds like the Shar Pei, Chow Chow, Kerry blue terrier and Collie. Animal Eye Care LLC also cites Pugs, Shih Tzus and Pekingese as at-risk breeds. The shorter the dog's nose, the shallower the pet's eye socket. This causes the dog's eyes to look extremely prominent.

Symptoms

Dogs with macropalpebral fissure syndrome can't blink their eyelids effectively. Veterinarians refer to this problem as lagophthalmos. Affected dogs tend to manage small but incomplete blinks. As a result, the cornea of each eye is continually exposed to the air. Owners might note that a dog with this disorder sleeps with its eyelids only partially closed.

Some dogs with the syndrome have a prominent skin fold over the nose. These large nasal folds can rub and irritate the surface of an eye and interfere with the dog's ability to see.

Another sign of macropalpebral fissure syndrome is an abnormal growth of hair inside the corners of the dog's eyes. This causes constant rubbing against the cornea, particularly if the dog is a Shih Tzu.

Upon examination, vets often also note that skin on the inside corner of the dog's eyes rolls inward. This causes any surface hair to irritate the surface of the eye. Dogs with this problem attempt to rub their faces frequently.

One of the biggest risks of this syndrome is that one or even both eyes will pop out of the respective eye socket if the dog is somehow hit. This can lead to blindness and sometimes the necessity to remove the affected eye.

In general, dogs with macropalpebral fissure syndrome face an elevated risk of eye trauma and ulcers. In order to feel more comfortable, they love to rub their faces on rough surfaces like furniture upholstery or carpeting.

They're also at an increased risk for blindness as scar tissue forms on their corneas. Some become blind by age five. Sometimes this isn't obvious to the owner because dogs typically don't bump into things until most of their vision is gone.

Treatment

It's often difficult to treat these dogs. Some symptoms like dry eyes require topical medications. Surgery to graft tissue to treat severe ulcers is sometimes necessary.

Animal Eye Care LLC indicates that the preferred treatment for dogs with macropalpebral fissure syndrome is a type of plastic surgery known as medial canthoplasty. The surgeon sutures the inside corners of the dog's eyelids closed. This narrows the opening of each eye and causes it to take on an almond shape.

During this procedure, the vet also removes any abnormal hairy tissue causing abrasion and also corrects other structural problems. While this procedure isn't foolproof as far as preventing future problems in at-risk breeds, it can lessen the frequency and severity of issues related to macropalpebral fissure syndrome in dogs.

Sources:

http://www.vin.com/VINDBPub/SearchPB/Proceedings/PR05000/PR00520.htm

http://www.animaleyecare.net/diseases/macropalpebral.htm