When to see a vet urgently
Do not assume a sudden visual problem is slowly progressive PRA. Seek immediate assessment if:
- your cat suddenly bumps into objects and cannot find familiar routes
- the pupils remain enlarged or are different sizes
- blood is visible in the eye
- a vision change accompanies eye pain, strong squinting or keeping an eye closed
You can find a vet near you. Prompt treatment can affect preservation of sight in some causes of sudden blindness.
Overview
Progressive retinal atrophy (PRA) is one of the most studied inherited diseases in animals. It occurs less often in cats than in dogs, but cases have been described particularly in certain breeds. As well as inherited forms, retinal atrophy can develop secondarily after eye inflammation, chronic infections or injuries. Retinal photoreceptors ultimately degenerate, vision deteriorates and blindness occurs in the final stage.
There are two main photoreceptor types: rods allow vision in dim light, while cones contribute to colour discrimination, among other functions. In many forms of PRA, rods are damaged first, so moving in dim light becomes difficult before daylight vision is affected. Not every inherited form progresses in the same order or at the same age, however.
In retinal developmental disorders, visual cells fail to develop normally. In later-onset degeneration, they function initially but gradually deteriorate. This explains why some inherited diseases appear in kittens and others only in adults.
Causes
Key causes and predisposing factors include:
- genetic susceptibility, for example in Abyssinian and Somali cats
- eye inflammation, such as uveitis and chorioretinitis
- infections, such as FIV, FeLV and toxoplasmosis
- eye injuries
- dietary taurine deficiency from dog food, vegetarian or unbalanced homemade diets, causing central retinal degeneration; drug-induced damage, particularly high amounts of the antibiotic enrofloxacin in cats, which can cause sudden blindness; high blood pressure, a common cause of retinal detachment and blindness in older cats
- ageing and natural degeneration of retinal cells
PRA means a group of inherited retinal diseases; not every acquired retinal injury is called PRA. Retinal detachment caused by high blood pressure, inflammation and taurine-deficiency degeneration, for example, are distinguished during investigation. They may impair vision similarly, but treatment possibilities differ.
Ageing alone is not a sufficient explanation for progressive or sudden blindness. A visual problem in an older cat prompts investigation of high blood pressure and other eye diseases, among other possibilities. Tell your vet about every medicine and when each was started because toxic retinal damage can develop rapidly.
Risk factors
- Inherited breed susceptibility in Abyssinian, Somali, Bengal, Persian and Siamese cats; DNA tests are available for some breeds.
- Older age.
- Chronic viral infections.
- An unbalanced diet.
- Eye injuries.
Breed alone does not determine one genetic test suitable for every cat. Disease associated with the rdAc variant in the CEP290 gene and the Rdy form in the CRX gene, for example, are different conditions. A separate inherited form has also been described in Bengals. Test suitability depends on the family line and variant being investigated.
Information on the significance of every general risk factor listed specifically for PRA is limited. Infection or dietary deficiency can be associated with acquired damage but does not itself establish inherited PRA. The cause of symptoms is not inferred solely from breed or age.
Symptoms
Early signs can be subtle:
- poor low-light vision, or night blindness
- difficulty finding the way in dark spaces
- enlarged pupils that respond poorly to light
- increased retinal reflectivity during eye examination
- gradual sight deterioration leading to blindness
In the final stage, a cat no longer navigates familiar surroundings, bumps into objects and loses confidence moving around.
A familiar environment can conceal declining vision for a long time. Cats learn routes and use other senses, so the first clear difficulty may appear only after furniture is moved. Blindness therefore does not always mean a cat can no longer move around its home.
Watch for reluctance to enter a dark room, hesitation when moving and pupil changes. Eye shine in light alone does not confirm diagnosis because the back of the eye naturally contains a reflective layer. Abnormal retinal reflectivity is assessed as part of examination of the back of the eye.
Possible complications
The main consequence of retinal atrophy is complete, irreversible blindness. Pain or marked inflammation is not usually present, but sight loss significantly reduces quality of life unless you adapt the surroundings.
Visual impairment alone does not mean poor quality of life. Many cats that gradually become blind adapt well when their environment remains safe and predictable. Pain or marked redness is not a typical consequence of ordinary PRA and may indicate another or concurrent eye disease.
In acquired sight loss, the prognosis depends on the cause. With blood pressure-related blindness, vision sometimes returns if treatment starts promptly, but damage often remains permanent. Do not wait at home after a sudden change, even if retinal atrophy has previously been discussed.
Diagnosis at the vet
Your vet can confirm the diagnosis using:
- eye examination with an ophthalmoscope
- electroretinography, or ERG, to assess retinal function
- blood tests to exclude infections and metabolic disorders
- genetic tests if an inherited form is suspected
Examining the eyes and the whole cat
An ophthalmoscope is used to inspect the back of the eye. As PRA progresses, narrowed blood vessels and increased prominence of the reflective area may be seen. Visible changes can be slight early on even when retinal function has already declined. Ordinary visual examination alone therefore does not rule out every early form.
ERG measures the retina's electrical response to light. It describes function rather than tissue appearance alone and can detect an abnormality before obvious blindness. A vet experienced in eye disease assesses the need for the investigation and interprets its result alongside symptoms and the rest of the eye examination.
Blood pressure is measured if pressure-related retinal damage is suspected. Anxiety at the clinic can raise the reading, so measurement is performed calmly and assessed with other findings. Dietary history and blood taurine testing where necessary are part of investigating suspected deficiency. Inflammation and infection tests are selected according to symptoms.
What does a genetic test show?
The rdAc form is recessively inherited: disease requires two copies of that variant. A carrier with one copy may have normal vision but can pass it to offspring. In the CRX-associated Rdy form, a single copy can cause early disease, so results are interpreted differently.
A negative result means the tested variant was not found. It does not exclude another inherited form, a blood pressure problem or another eye disease. A genetic test alone also does not measure how well the cat sees at that moment. A cat with symptoms needs an eye examination regardless of the test result.
Treatment and monitoring vision
No curative treatment is currently available for inherited PRA. Vitamins or antioxidants have not been shown to stop it. Acquired damage instead requires treatment of its underlying cause, such as high blood pressure, confirmed inflammation or nutritional deficiency. Any return of sight depends on the extent of existing damage.
Correcting taurine deficiency can halt progression of the associated retinal degeneration, but existing changes at the back of the eye may remain permanent. The heart may also need examination because deficiency can affect heart muscle too. Supplement needs and dietary changes are assessed with your vet.
Follow-up monitors changes in sight and the back of the eyes and any other eye diseases. New eye pain is not automatically interpreted as part of familiar PRA. Suddenly faster sight deterioration also needs reassessment because several problems affecting vision can coexist.
Safe daily life with declining vision
Keep feeding places, water bowls, the litter tray and furniture in the same positions. Do not leave objects on familiar routes. Let your cat explore at its own pace and avoid lifting it onto a high surface from which it could fall. Access to stairs can be limited until your cat navigates them safely.
Speak before touching your cat so it knows you are approaching. Use your voice to guide it to a familiar place where needed. A safe indoor environment or protected outdoor access reduces the risk of getting lost and injury. Play and other activities can continue according to your cat's abilities; declining sight does not remove the need for enrichment.
Prevention
- Use genetic testing in breeding programmes for susceptible breeds.
- Treat eye diseases and infections promptly.
- Provide complete nutrition containing enough taurine.
- Arrange regular veterinary eye examinations, particularly for older cats.
Breeding plans combine genetic information appropriate to the family line with eye examinations. A symptom-free carrier is not the same as a clinically affected cat, but mating two carriers of a recessive form can produce affected kittens. Nutritional balance reduces the risk of deficiency-related damage but does not alter a cat's genes or cure inherited PRA.
This text provides general information and does not replace veterinary care. Contact a vet if your cat develops symptoms.
Frequently asked questions
Can a cat with PRA move around at home even when blind?
Yes. A cat gradually losing sight can learn familiar routes and use smell, hearing and touch. Keeping objects in place and removing obstacles supports safe movement. Adaptation varies individually.
Does a negative PRA genetic test rule out every eye disease?
No. The test examines a particular genetic variant, rather than every inherited or acquired visual disorder. A cat with vision symptoms is always examined even after a normal result on one PRA test.
Does taurine help inherited PRA?
Correcting taurine deficiency is important in deficiency-related retinal damage. However, it is not a proven treatment for inherited PRA. Dietary assessment and a precise eye diagnosis therefore complement one another.
This article is for general information only and is not a guide to treatment. If you notice the first signs of illness, contact your vet.
Paw4care editorial team
Sources
- Disorders of the Retina, Choroid, and Optic Disk (Ocular Fundus) in Cats, Merck Veterinary Manual, accessed 2026-11-03.
- Progressive Retinal Atrophy (PRA rdAc) (Abyssinian), University of California, Davis Veterinary Genetics Laboratory, accessed 2026-11-03.
- Progressive Retinal Atrophy (PRA Rdy) (Abyssinian), University of California, Davis Veterinary Genetics Laboratory, accessed 2026-11-03.
- Progressive Retinal Atrophy in Cats, VCA, accessed 2026-11-03.
- Retinadysplasie und -degeneration der Katze, Ludwig-Maximilians-Universität München, accessed 2026-11-03.
- Hypertension, Cornell University, accessed 2026-11-03.
- Blind Cats, Cats Protection, accessed 2026-11-03.