CATARACT: What Is It & How Is It Treated
Cataracts are a leading cause of blindness. Although most prevalent among older pets, a cataract can occur in young animals as well.
WHAT IS A CATARACT? A cataract is opacity (clouding) of the lens of the eye which blocks or changes the passage of light through the eye. The lens of the eye is located behind the pupil and normally is transparent. Its role is to help focus images onto the retina at the back of the eye which transmits the images to the brain. Cataracts are not contagious and are not an infection.
CAUSES OF CATARACTS. Although the inciting cause is not known, it is known that a cataract is associated with chemical changes within the lens. Most often a cataract is related to the normal aging of the pet—and the eyes. Other factors that play a role may be infection, hereditary influences, congenital events such as viral infections in the mother before birth, physical or chemical injury to the eye, and exposure to intense heat or radiation. Eye diseases and certain generalized diseases, such as diabetes, can also lead to cataract development.
WHAT ARE THE SIGNS? Cataract formation is not associated with pain, redness, or tearing. The signs of a cataract are those associated with interference with vision. As the cataract matures, it becomes noticeable as a milky spot in the normally black pupil.
When the area of clouding is small and away from the center of the lens, there may be little interference with vision. However, as the cataract progresses, it becomes larger and larger.
TREATMENT for a large cataract is surgery, which offers a safe and successful means to restore vision in the majority of uncomplicated cataract patients. If the cataract is very small, sometimes it is possible to improve vision by using atropine eye drops to keep the pupil dilated, allowing vision in areas of the lens not affected by the cataract. In many instances, the pet never experiences visual difficulty to the point that surgery is recommended.