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Cat eyes are the most beautiful among mammals, with their vertical pupils and vibrant irises of many color variations. However, like all mammals, a cat’s eye can develop medical problems that need veterinary attention. One such possible issue is iris melanosis, a feline-specific condition in which one of the irises develops dark, small, and flat “freckles.” This condition is typically benign, but it can turn into malignant cancer in some cases. Read on to learn more about this issue.
What Is Iris Melanosis?
Iris melanosis is a feline-specific condition in which the iris becomes pigmented. This means the pigmented cells (melanocytes), which produce the melanin responsible for the color of hair, skin, and eyes, change. The melanocytes incorrectly replicate and spread over the surface of the iris. If this happens, the condition should be monitored closely by your veterinarian because while it could stay benign for years, it could unpredictably turn into feline diffuse iris melanoma, a malignant cancer.
Other complications could arise from iris melanoma, such as glaucoma caused by the blockage of intraocular fluid drainage. The condition usually occurs in one eye, but it can develop in both eyes. Another possible complication is the iris muscles not functioning properly if severe lesions occur, which makes it difficult for the cat to constrict the pupil in response to bright light.
What Are the Signs of Iris Melanosis?
Signs of iris melanosis are small brown flat freckles, or “nevus,” on the iris. The coloration can show areas of brown or dark pigmentation on the surface. These spots often start out small but gradually increase in size. The condition can appear in one or both eyes. If the lesions become bumpy or raised, this is a cause for concern since it might be a sign of developing iris melanoma.
What Are the Causes of Iris Melanosis?
A pigment change in the eye is iris melanosis. This change occurs when pigmented cells (melanocytes) inappropriately spread and replicate over the iris’s surface. The main threat of iris melanosis is the possibility of the condition turning into iris melanoma. Unfortunately, there is no way of determining definitively if this will happen, which is why strict monitoring is necessary to compare any changes, such as raised lesions (lesions are benign if flat), rapid pigment increase, pupil changes, or pigment thickening or growth that spreads to the edge of the iris.
If any of these changes occur, removal may be recommended by a veterinarian ophthalmologist. Eye removal may seem drastic, but it’s done as a preventative measure to keep the malignancy from spreading to vital organs, such as the liver, lungs, kidneys, spleen, lymph nodes, brain, and bone, any of which can be fatal. An iris biopsy might be performed by veterinary ophthalmologists to determine if cancerous cells are present.
How Do I Care for a Cat With Iris Melanosis?
The only care available for iris melanosis is closely monitoring the condition due to the possibility it could turn into iris melanoma, which is a cancerous condition that often requires the removal of the affected eye.
Monitoring is extremely vital in noting any changes so the next best course of action can be taken. The brown spots that occur from iris melanosis will likely never resolve, but as long as the condition does not turn cancerous, your cat can still live a normal and healthy life with no pain in the affected eye.
Some ophthalmologists may recommend laser therapy that targets the destruction of the iris melanosis. However, laser treatment has not yet been proven by scientific studies to be effective.
Keep in mind that color changes with dark spots in the eye may be an inherited trait and cause no harm to your cat, but it’s imperative that you take your pet to your veterinarian if you notice any changes whatsoever in their eyes to be safe. Never ignore changes in the eye, as these could indicate a more serious medical issue.
Frequently Asked Questions (FAQ)
Does Iris Melanosis Spread?
Small spots may form into one large mass in larger areas of pigmentation, or the spots themselves may grow larger individually.
What Will My Vet Do If My Cat Develops Iris Changes?
Your veterinarian will perform a complete examination of your cat’s eyes that will include intraocular pressure measurement, fundus observation, gonioscopy, and ultrasound. Depending on the findings, your veterinarian may recommend a biopsy or removal of the eye (enucleation), or they will establish a monitoring protocol for you to follow. This will ensure that any subtle changes in your cat’s iris are detected, and melanoma, if it develops, will be detected in the early stages.
Conclusion
Iris melanosis is not a threat as long as it does not develop into iris melanoma. The condition causes your cat no pain or vision problems. Close monitoring and regular trips to your veterinary ophthalmologist are vital to detect any subtle changes. The first sign of iris melanosis is a small and flat (not raised) freckle in the iris. This pigmentation change can last many years before it may turn into iris melanoma, which is why close monitoring is crucial.
Remember, there is no way to tell if iris melanosis will develop into cancer, and melanoma can arise quickly and unexpectedly.
Featured Image Credit: Mary Swift, Shutterstock
