Often associated with inflammation as well as advancing years, cataracts can eventually cause blindness if left untreated.
Despite what some people may believe, the term “cataract” doesn’t derive from the word “cat”. In fact, dogs develop cataracts more often than cats do. Nevertheless, this eye condition does occur in felines, so it’s important to know something about them. I once wanted to be an “animal eye doctor” but my career took a different path and I evolved into the holistic practitioner I am today. Although I often see cats with cataracts in my practice, I also consulted veterinary ophthalmologist, Dr. Kristen Fahrer, for more information on this ocular condition and its treatment.
What are cataracts?
A cataract is an opacity in the otherwise translucent lens of the eye. It prevents light from moving properly from the outside world to the retina (the light sensitive layer lining the back of the eye). Cataracts can mildly reduce or completely obstruct the movement of light through the lens. As a result, vision will be minimally or severely impaired.
Not all clarity-altering changes to the lens are consistent with cataracts. Nuclear (lenticular) sclerosis, a non-pathogenic process, is an age-related phenomenon in which older fibers are clustered in the center (the nucleus) of the lens. Some light still passes through these densely packed lens fibers. Reportedly, the sensation is akin to looking through fog or haze. Although cataracts can cause cats to go blind, nuclear sclerosis will not.
Cataracts are not directly dangerous, but with the diseases with which they are associated, or the potential for the opacified lens to luxate (come loose from attachment), can be. Once lens luxation occurs, glaucoma (increased intraocular pressure) and blindness often occur.
Why do cats develop them?
There is no single reason why cats develop cataracts. According to Dr. Fahrer, inflammation plays a key role in their development, so any inflammatory process that affects the eye can contribute to their formation. She says that correlating factors can contribute to the development of cataracts, including genetics and the presence of inflammation in the globe (eyeball) and extraocular structures (outside of the eye). The potential for cataracts to be passed on from one generation to another, regardless of the cat’s status as pure or mixed breed, certainly exists. Additionally, cats progressing from the adult to geriatric life stage are more prone to cataracts.
Inflammation is the body’s enemy on multiple levels, so the eyes or other systems can be negatively affected. Infection with viral or bacterial organisms can cause inflammation and other abnormalities inside the feline eye, therefore increasing the potential for cataracts. Even certain treatments used to manage other aspects of feline health, such as radiation treatment for tumors, or administration of and exposure to certain drugs, can play a role in cataract development.
How do I know if my cat has cataracts?
You may notice that your cat has increasing difficulties navigating his environment. Being less able to gracefully land on previously easily-surmountable heights is one sign. Your cat could also bump into furniture, the litter box wall, or other objects (or even other animals). You may also see the change in your cat’s eyes when light shines through the pupil and illuminates the cataract-filled lens. The best means to diagnose cataracts is through an examination with your veterinarian or a veterinary ophthalmologist. An ophthalmoscope (a light-affixed magnifying glass) and other diagnostic tools will be needed to provide a thorough ocular workup.
How are they treated?
When it comes to treating feline cataracts, Dr. Fahrer’s primary recommendation is to get any inflammation in the eye and elsewhere under control. Depending on the cause, this process may involve oral or topical medications. Once the inflammation is reduced, a more definitive treatment involving surgery to remove the cataract may be pursued. Some cats even have an artificial lens implanted, although removing the cataract without implanting an artificial lens still permits better vision and improved overall ocular health, as opposed to leaving the abnormal lens in place.
To promote both short and long-term ocular health in your cat, it’s best that he have a veterinary examination at least once a year. By checking your cat’s eyes on a regular basis, your veterinarian can find the signs of cataract development before they cause significant symptoms!