CATARACTS

General Information

A cataract is any abnormal opacity (cloudiness) of the lens or its outer covering (capsule). The opacity may range from a tiny spot to total loss of transparency.

The lens is an M and M-shaped transparent structure that lies directly behind the iris and pupil. The cornea, aqueous humor, lens and vitreous body are elements that bend (refract) light waves to form an image upon the retina. The cornea accounts for about 80% and the lens for 20% of the light-bending action.

Causes of cataracts include heredity, metabolic defects, injuries and aging. The rate of cataract development ranges from a few days to years.

We receive many concerns from pet owners about cataracts and their older pets. In many cases, the lens will develop a grayish hue as pets age. This is a normal part of growing older in dogs and cats and is not a cataract. This condition is called lenticular scleroses.

Important Points in Treatment

Lens removal (cataract surgery) in animals is not as successful as in people, due to structural and physiologic differences between people and animals. Also, normal animal behavior can result in post- surgical injury, while people can be told to observe certain precautions.

Artificial lenses are usually not necessary after surgery, however, they have shown some benefit in selected cases. Some animals do not see for several weeks after surgery; others see after a few days.

Some pets may not be suitable for cataract surgery due to age, health and psychological make-up. If your pet should not undergo surgery, do not be discouraged, since it will probably be an acceptable pet despite its handicap.