* CATARACTS
The normal lens of the eye is a focusing device that is completely clear and held in place by fibres just inside the pupil. Despite its clarity the lens is made of tissue fibres. As the pet ages the lens cannot change its size and grow larger, rather it becomes more compacted with fibres. This increased density appears cloudy and is called nuclear sclerosis. The lens can still transmit light and the pet can still see - these are not cataracts.

A cataract is a change in the lens that renders it completely opaque and if involving the entire lens will result in blindness. A pet may be born with a cataract (congenital) or it may develop with age due to a genetic predisposition or other causes which include diabetes, inflammation, trauma, dietary deficiencies, electric shock or toxin.

Diabetes mellitus is a condition in which the blood sugar levels become very high. This results in a high concentration of glucose within the fluid in the eye which, when absorbed by the lens, transforms into sorbitol. This draws water into the lens, causing irreversible cataracts in each eye. Cataracts are virtually unavoidable in diabetic dogs regardless of how good the regulation is. Diabetic cats on the other hand have an alternative glucose metabolism in their eyes and do not get cataracts.

Cloudiness on the surface of the eye (the cornea) may be mistaken for a cataract by some owners but actually represents other eye diseases. It is therefore important to have any cloudiness within the eye assessed by your vet.

With time a cataract may slip from its normal position and cause an increase in pressure within the eye (glaucoma). Alternatively a cataract may start to dissolve, resulting in inflammation and pain. A cataract does not necessarily require treatment if the above conditions are not present. The majority of blind animals have a good quality of life providing their environment is not changed too much. Occasionally a pet may become anxious or even aggressive when they lose their vision.

Cataract treatment involves surgical removal or physical dissolution of the cataract under general anesthetic. Prior to any surgery a special test is performed to ensure that the retina is still working and make sure that the pet will definitely benefit from surgery.