The lens is a highly transparent and complex structure. Disruptions of this fragile system will result in a loss of transparency and a decrease in vision.
What causes a cataract?
The most common cause of cataracts in dogs is genetic. Most breeds, and even mixed breeds, have been found to have genetic cataracts. The breeds with the highest incidence of cataracts include Boston Terriers, Miniature Poodles, American Cocker Spaniels, Standard Poodles, and Miniature Schnauzers. The average age of onset for genetic cataracts is 4-7 years. However, dogs as young as 6 months have developed genetic cataracts, and the younger the age of onset of a genetic cataract, the more rapidly the cataract progresses.
Diabetes is the second most common cause of cataracts in the dog. 80% of diabetic dogs develop cataracts within 6 months of diagnosis. Diabetic cataracts are very aggressive, progress quite rapidly, and can result in sudden vision loss.
Other causes of cataracts include intraocular inflammation, certain retinal diseases, and trauma.
What is the treatment for a cataract?
The treatment for cataracts in dogs is the same as in people, the surgical removal of the lens in a process known as phacoemulsification. This advanced procedure allows for the complete removal of the lens and placement of an artificial lens that will result in the return of normal vision. Success for phacoemulsification in dogs is 90-95%. Success is defined as a visual and comfortable eye.
What may happen if I do not treat the cataract?
Unfortunately, cataracts are not an entirely benign disease. Failure to remove cataracts may not only result in the progressive loss of vision, but if a cataract becomes very advanced, termed a hyper mature cataract, it can result in potentially painful complications such as intraocular inflammation, glaucoma, and lens luxation.
Normal dogs have a rough visual acuity of 20/80 (normal human = 20/20). Dogs that have had their lenses removed are extremely far-sighted, termed hypermetropic, and have substantially reduced visual acuity, approximately 20/850. Through extensive optical evaluation, an artificial intraocular lens has been designed specifically crafted for the unique ocular characteristics of the dog. Dogs receiving artificial lenses are corrected to within 1 diopter of emmetropia and have essentially normal vision.