Golden Retriever pigmentary uveitis, a unique eye condition primarily affecting this breed, is both concerning and commonly overlooked. Characterized by a gradual deposition of pigment on the uvea, the middle layer of the eye, this disease can lead to serious complications, including glaucoma and blindness. In this article, we will discuss the cause, symptoms, and treatment options to help you better understand this disease.
What is Golden Retriever pigmentary uveitis?
Golden Retriever pigmentary uveitis is a progressive ocular disease that is quite common in this breed.
It is a form of uveitis, which is inflammation of the uvea (colored portion of the eye), but with the added complication of pigment dispersion. This means that pigment from the iris starts to spread to other parts of the eye, which can cause blockages and increase pressure within the eye, leading to glaucoma.
In Golden Retrievers, the occurrence of this condition varies, with 6% to 18% of the breed being affected. Interestingly, the incidence rises to 25% in Goldens aged between 6 to 8 years.
What causes pigmentary uveitis in dogs and how does it develop?
Pigmentary uveitis is a condition that seems to run in Golden Retriever lines, suggesting that it is genetically inherited, or passed down from parent dogs to their puppies.
Unlike some other types of eye diseases, pigmentary uveitis doesn't seem to be caused by infections, cancer, metabolic issues, or injuries.
The development of pigmentary uveitis in Golden Retrievers isn't fully understood yet. It most likely starts with the formation of thin-walled cysts in the iris, which is the colored part of the eye.
These cysts, along with the spread of pigment (color) and a low-grade, long-lasting inflammation in the eye, can lead to a serious condition called secondary glaucoma.
Glaucoma occurs when there's too much pressure inside the eye, which can damage the eye and lead to vision loss. It can develop due to various changes in the eye, such as the formation of fibrous scar tissue, blockage in the drainage angle of the eye, and adhesions in the eye.
While Golden Retriever pigmentary uveitis usually affects both eyes (up to 90% of cases), it can sometimes be worse in one eye than the other, or even just affect one eye.
What are the symptoms of Golden Retriever pigmentary uveitis?
The symptoms of Golden Retriever pigmentary uveitis can vary and may not be immediately noticeable.
The earliest and most telling sign is seeing radial, or spoke-like, pigment deposits on the front part of the lens in your dog's eye. This is a very telling sign of pigmentary uveitis in Golden Retrievers.
Other early signs can include redness, cloudiness, or a noticeable change in the color of the eye.
As the disease progresses, the potential for glaucoma increases and can occur in up to half of all cases of pigmentary uveitis.
If glaucoma does develop, you may notice signs such as squinting, pain and discomfort, and sometimes reduced vision or blindness.
If you notice any of these symptoms in your dog, please see your veterinarian as soon as possible for further assessment.
How is pigmentary uveitis diagnosed in dogs?
Pigmentary uveitis in dogs is diagnosed through a thorough ocular examination by your veterinarian. This examination may include a detailed history, visual inspection, and specific tests such as tonometry to measure eye pressure. We expect the intraocular pressures to be low with uveitis but can be high if there is secondary glaucoma present.
If pigmentary uveitis is suspected, your vet may refer you to a veterinary ophthalmologist for further testing and treatment.
What is the treatment for pigmentary uveitis in dogs?
There's no specific cure for pigmentary uveitis and pigmentary cystic glaucoma yet. The best way to handle it is to start treatment early and control ocular inflammation.
This can help prevent or delay glaucoma and vision loss. Treatment plans often use a mix of medicines to reduce inflammation and/or fight glaucoma. If the pressure inside the eye goes up, strong glaucoma treatment is needed to keep vision and reduce discomfort.
To address and control intraocular inflammation in dogs, we use a topical corticosteroid called prednisolone. Prednisolone has the ability to pass through the cornea and enter the inside of the eye, where the source of inflammation is.
Given that glaucoma frequently occurs as a result of pigmentary uveitis, most veterinarians recommend starting anti-glaucoma medications. Starting anti-glaucoma medications does not guarantee that it will not develop, but will greatly reduce the chance. Examples of anti-glaucoma medications are carbonic anhydrase inhibitors or beta blockers.
In very severe cases, we will combine topical medications with oral medications for a more aggressive approach.
What is the prognosis for Golden Retrievers with pigmentary uveitis?
Eyes that are affected often need treatment for a long time, sometimes for life. Regular check-ups and adjusting medications carefully are very important to help your dog keep their vision for longer, slow down the disease, and reduce the risk of further health problems.
However, even with the right treatment, the prognosis for pigmentary uveitis is uncertain. Because pigmentary cystic glaucoma usually doesn't respond to anti-glaucoma treatments in the long term, the prognosis for late-stage disease is not good.
Can pigmentary uveitis in dogs be prevented?
There is no definitive way of preventing pigmentary keratitis in your Golden Retriever. Prevention is focused on sound breeding practices to prevent the incidence within the breed.
Golden retrievers used for breeding should have eye exams every year.
If pigmentary uveitis or pigmentary cystic glaucoma is found, the affected dogs should not be used for breeding, and their puppies should be regularly checked for signs of the disease.
Because uveal cysts don't always cause pigmentary uveitis, golden retrievers that only have uveal cysts can be bred based on current guidelines.
How is this condition different from anterior uveitis?
Technically, pigmentary uveitis is a type of anterior uveitis. They differ in breed specificity, symptoms, and cause.
Anterior uveitis typically affects a wide range of breeds and is often caused by an underlying systemic disease or infection.
On the other hand, pigmentary uveitis is somewhat specific to Golden Retrievers and is believed to be genetic. The symptoms of pigmentary uveitis are also more subtle and can often go unnoticed until the disease has progressed significantly.
Golden Retriever pigmentary uveitis is a notable eye condition that requires attention and understanding from pet owners. This genetic disease, marked by pigment dispersion and eye inflammation, can lead to complications like glaucoma and vision loss. Early detection through symptoms like pigment deposits on the lens and eye redness is very important. While there's no cure, managing the condition with early, aggressive treatment can help control symptoms and slow disease progression.