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 an advanced cataract develops, the pupil may appear white. Vision through a mature cataract is like looking through white painted glass.
How are Pet Cataracts treated?
As of right now, there are no medications which are effective in treating cataracts. More on this subject here. A cataract is not a growth, it is a change in color and opacity of the normal lens structure. Treatment requires surgical removal of the discolored lens material and, once removed, the cataract will not recur. Cataracts are not treated with lasers in people or in pets; rather, lens removal utilizes phacoemulsification ultrasound technology to break up and remove the lens material, which is the same procedure used in people. Once the lens is removed, it is replaced with an artificial lens inserted into a 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, replacement of the lens may not be possible. Cataract removal without lens replacement results in vision which is somewhat blurry but much 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 video which further explains cataract surgery.
How effective is Cataract Surgery for Dogs, Cats, and Other Pets?
Cataract surgery is approximately 85% successful. However, this means that in 15% of cases, complications may prevent vision recovery or result in later vision loss. The purpose of the examinations before and after cataract surgery is to detect, prevent, or treat these complications early whenever possible. In uncomplicated cases, vision will begin to noticeably improve within a few days; after six weeks, healing is usually complete and vision is at its best.
Preparing for Your Pet’s Cataract Surgery
Once the doctor has examined your pet and cataract surgery has been agreed upon, a blood analysis will be done to detect any generalized illness and assess any inherent risks associated with general anesthesia. Eye drops will be dispensed to be started before the cataract surgery. You will use these medications after the cataract surgery as well. Your pet will be admitted to the hospital on the morning of the cataract surgery. The hair will be clipped from the area around the eyes and one the front legs (to administer the anesthetic). Prior to the operation, an electroretinogram test will be performed to confirm adequate function of the retina.
After Cataract Surgery
The cataract surgery takes approximately one hour per eye. Your pet will be monitored in the hospital for a few hours after cataract surgery. Although overnight hospitalization is not required, he will need to come back for the first re-examination the day after cataract surgery. When your pet goes home, he will be wearing a firm plastic collar to prevent him from rubbing at the eyes. Although he may not like it, he will learn to tolerate the collar and can eat and sleep with it on. It is essential to avoid injury to the eyes after this delicate surgery. Please keep your pet quiet and avoid direct nose to nose contact with other animals during the first two weeks post-surgery. No bathing or uncontrolled exercise. Leash-walking is acceptable. Following cataract surgery (in people as well as dogs) there is no substantial discomfort; thus pain medication is not necessary. Dogs have a greater degree of post-operative inflammation, however, so anti-inflammatory medications are used extensively and for a longer period after surgery than is needed for our human counterparts. Additional re-examinations will be scheduled at 1, 2, 4, and 6 weeks after the cataract surgery to monitor progress and then as needed.
Here is a movie explaining more about cataract surgery for your pet. Double click on cataract movie to begin.
Click here for more information on cataract surgery and what is involved.