Progressive retinal atrophy in cats

Written by Liz Palika Reviewed by Kristin Westafer, DVM

Overview

The retina is located at the back of the eye and is responsible for transmitting information from the eye to the brain. Eye problems associated with the retina are more common in dogs than they are in cats, but they can be seen. Retinal atrophy can be progressive, or slowly gets worse over time, or very sudden. Progressive retinal atrophy occurs slowly and many owners do not notice that their pet has lost vision until they move furniture or change something in the house. Pets will typically lose the ability to see well in dim light first before coming completely blind; this may or may not go unnoticed. A diet deficient in the amino acid, taurine, will also cause retinal atrophy. Commercial diets are sufficiently supplemented with taurine, however, cats fed an inappropriately balanced homemade diet are still at risk.

A healthy retina is vital to vision. When the retina is damaged in any way, due to accident, poisoning, high blood pressure, infection, or a genetic cause, the cat's vision will decrease, even to the point of blindness. Feline Progressive Retinal Atrophy (FPRA) is an umbrella term that refers to several types of retinal problems, all of which can cause blindness. When retinal atrophy occurs alone, it is not a painful condition and animals adjust well to blindness.

A genetic predisposition has been found in some Abyssinians and Persian cats. However, cats of any breed can be affected by either sudden or progressive retinal atrophy.

Symptoms

FPRA is not usually associated with any discomfort or pain. Instead, the cat's actions usually cause the owner to bring the cat in to the veterinarian for a check up.

The cat walks into things, including the furniture, or objects left in a place where they are not normally located
The cat stops jumping up on objects
The cat stops jumping down from objects
The cat initially appears timid or fearful; a difference from the normal personality
The cat’s eyes are red or appear larger than normal
There is an increased green shine to the eye

Symptoms may appear at different ages, depending upon the form or cause of the FPRA.

Cause and prevention

A retina can become detached or damaged due to many causes.

Head trauma can cause one or both retinas to detach, partially or completely.
A viral infection that occurs in the mother early in pregnancy can cause eye (and retinal) abnormalities in the kittens.
A taurine deficiency can lead to the development of Central Progressive Retinal degeneration. Cats with taurine deficiency have the same symptoms as those cats with progressive retinal atrophy, however, they often also have heart problems as a result of the deficiency and heart murmurs, fainting, and other signs of heart disease may be appreciated by your veterinarian.
Feline Central Retinal atrophy can also be caused by a nutritional deficiency of Vitamin E or Vitamin A. High levels of selenium in a diet can also cause blindness. Most commercial diets are adequately supplemented and cats fed homemade diets are at an increased risk.
There are several forms of FPRA caused by inherited genes, especially in the Abyssinian and Persian cat breeds.
High blood pressure can cause sudden retinal degeneration/detachment. Causes of this include kidney disease, heart disease, or rarely adrenal disease.
Infections or cancer in the eye can also cause retinal atrophy.

Preventing FPRA requires good care for the cat, preventing accidents that could cause head trauma, and feeding a balanced, nutritional diet that contains all of the nutrients cats need, including vitamin E, Vitamin A, and taurine. Keeping pregnant or soon to be bred female cats away from strange, unvaccinated cats to lessen the chance of disease is also important. All breeding stock should also have their eyes examined prior to being used for breeding.

What to expect after blindness

Many indoor only cats can adapt well to a loss of sight. They may initially go through a very timid and fearful stage, and during this time, need to be protected so they don't hurt themselves. Confinement to one, safe room in the house is usually a good idea during the transition but once the cat has settled down, most can navigate the household fairly well.

The family dogs should be taught to never, ever chase the blind cat and children should be taught to be gentle. All family members need to talk to the cat when approaching her and before picking her up to avoid potential injury from a scared cat.