Disorders of the cat’s eye
TUMORS OF THE EYES
Seventy-five percent of eye tumors in cats are malignant, aggressive forms of cancer (in dogs, the ratio is reversed, 75 percent of tumors are benign and do not spread or become life-threatening). Iris melanoma is the most common type of tumor affecting the cat’s eye. Older cats may develop a visible brown or black spot on the iris of their eye. The iris is the colored part of the eye. The spots can be single or multiple and represent pigmented cells called melanocytes that have grown. The examination involves the use of a slit-lamp biomicroscope, which determines whether the tumor is cancerous or not. If the pigmented area of the iris is flat, the lesion is called Ins Melanosis. This is considered a pre-cancer and is checked every six months.
IRIS MELANOMA / GLAUCOMA
Melanoma of the iris is also called melanosis and/or melanocytoma. Melanoma of the iris is the term used if the pigmented area of the iris is raised. This is a cancerous lesion. Treatment involves using a diode laser to destroy the cancer cells. Without treatment, melanoma of the iris usually leads to glaucoma. Glaucoma occurs because cancer cells spread and obstruct the drainage angle of the eye, where the fluid in the eye normally drains. Because the fluid cannot drain from the eye, it builds up in the eye, which increases the pressure in the eye and causes glaucoma. In dogs, glaucoma quickly leads to blindness due to irreversible damage to the retina.
The only sign of glaucoma in cats may be a slight difference in the size of the pupils, which are the dark central area of the eye. Surgical removal of the eye, which is called enucleation, is often necessary in advanced cases of Ins Melanoma. This relieves the pain of glaucoma and removes the cancerous mass.
RETINAL DEGENERATION
Retinal degeneration is a hereditary disease in Abyssinian cats. It occurs between the ages of four and six and leads to blindness. Dietary deficiency of the amino acid taurine can also occur in cats fed primarily dog food, resulting in nutritional retinal degeneration. This condition was first described in 1975 and named feline central retinal degeneration (FCRD). Commercial cat foods are now fortified with taurine to prevent this problem.
#Disorders #cats #eye
