To be able to protect your pet’s vision is often not thought about until it is too late. I always tried to be observant and pro-active in my pet’s health yet keratoconjunctivitis sicca, also known as “dry eye”, snuck up on me and my dog a little over 4 years ago when he was only 8 years old. Since then I have learned more about eye health in dogs than I ever dreamed I would know. Cataracts is a subject I have just learned about.
What causes Cataracts?
Most cataracts in dogs have a hereditary basis. However, cataracts can also result from injury to or inflammation in the eye, or systemic diseases that have an affect on the eyes. Diabetes is the most common disease associated with cataracts in dogs. Although it may be difficult to name the specific cause of cataracts, generally those cataracts that develop in the eyes that are free of signs of disease (whether ocular or systemic) are assumed to be inherited.
Physiology of the eye
The lens is a living ocular tissue that, when healthy, is transparent. A normal lens helps focus the light on the retina, a light sensitive nerve tissue located in the back of the eye. A cataract is an abnormality of the lens in which an opacity, or a cloudy change in the tissue, scatters light. The normal composition of the lens is disrupted and its transparency is lost. If a large portion of the lens becomes a cataract, it prevents formed light from reaching the retina, causing poor vision. A cataract can assume a variety of appearances such as small spots, a cracked-ice appearance, a diffuse milky haze, a “pearl-like” sheen, or white streaks. The cataract may initially affect a small area and progress to involve a larger portion of the lens. The rate of progression is difficult to predict, though it tends to be more rapid in younger animals. Cataracts may develop in one or both eyes.
What is the treatment?
Early examinations are always recommended. A complete eye examination is a necessity. The health of the retina and other parts of the eye must be evaluated prior to the formation of complete cataracts. Sometimes an electroretinogram is recommended to evaluate the retina. The pet must see a specialist for the evaluation.
Medical remedies have been inaccurately advertised as effective for the treatment of cataracts. There is no proven medical treatment known to reverse or slow the progression of, or prevent the formation of, a cataract. Some promoted agents actually worsen the catatracts rather than improve the condition. Surgery is the only known treatment both in animals (and in humans), and often provides a return of functional vision in pets.
What does cataract surgery involve?
The various surgical procedures available for a pet are demanding and require meticulous and precise microsurgical techniques. Surgery is performed using an operating microscope and sophisticated microsurgical instruments. Two techniques are currently used to remove cataracts from the eye. Your specialist will determine the appropriate procedure for your pet.
When is surgery indicated?
Once a cataract has progressed to blindness in the affected eye, cataract surgery is often recommended. If one eye has a completely formed, vision-impairing cataract, and the opposing eye has a rapidly developing cataract, some veterinary ophthalmologists recommend surgery before the second cataract is complete. Surgery has been successfully performed on dogs and cats between the ages of 6 months and 18 years old. Your pet’s general health must also be evaluated and taken into consideration before cataract surgery.
This information was kindly provided by the American College of Veterinary Ophthalmologists (AVCO) and provided as a service by Northwest Animal Eye Specialists, located at 13020 NE 85th Street, Kirkland, WA 98033. Dr. Jones of Northwest Animal Eye Specialists is my dog’s eye care specialist. I recommend her highly!
If this article has been helpful for you, you might also want to read the other articles in this series:
If your pet has Dry Eye or Keratoconjunctivitis sicca, see a specialist promptly