What is a Cataract?

A cataract is a clouding of the lens inside the eye and is the most common cause of blindness in dogs. Cataracts can be caused by injuries or diabetes, but most cataracts in dogs are inherited. Any opacity in the lens is called a cataract; very small spots do not significantly affect vision. However, most cataracts will progress, and ultimately cause blindness. The lens is located behind the colored iris; thus when a cataract occurs, the pupil may appear white. Vision through a mature cataract is like looking through white painted glass.
 

A dog with complete cataracts giving
a white appearance to the eyes.

How are Cataracts treated?

There are no medications which are effective in treating or preventing cataracts. A cataract is not a growth; treatment requires surgical removal of the lens and, once removed, a cataract cannot recur. Cataracts are not treated with lasers; the surgery to remove the lens uses phacoemulsification, the same procedure used in people. Once the lens is removed, it is replaced with an artificial lens inserted into the pocket formed by the original lens capsule which remains in the eye. Occasionally, there is a weakness in this capsule which is detected during the cataract surgery. In these cases, sutures may be used to support the artificial lens. If replacement of the lens is not possible, the cataract will still be removed, with resulting vision which is somewhat blurry but significantly better than before surgery. One or both eyes may be candidates for cataract surgery; the doctor will discuss these options with you. We also have a videotape which further explains cataract surgery.

How effective is Cataract Surgery?

Cataract surgery is approximately 90-95% successful. However, this means that in 5-10% of cases, complications may prevent vision recovery. The purpose of the examinations before and after cataract surgery is to detect and prevent these complications whenever possible. In uncomplicated cases, vision will begin to improve within a few days; after six weeks, healing is usually complete and medication is discontinued.