Cataracts are an opaque, cloudy film that can form over the lens of the eye, impairing vision by reducing the amount of light that can pass through to the retina. While cataracts in cats aren’t as common as they are in dogs, they can still be a problem for animals of advanced age or that have a history of past eye trauma.
How Cataracts Affect Cats
Cataracts can appear as a cloudy haze over one or both pupils, sometimes with a blue, gray, or white tint to them or they may look like little blue shards of crystal in the center of the eye. Depending on the severity of the cataracts, eyesight could range from blurry vision to total blindness. Cataracts usually don’t cause pain, but severe cases can become painful and could eventually lead to blindness.
What Causes Cat Cataracts
The most common cause of cataracts in cats is eye injuries from fighting with other cats, but they can also be caused by malnutrition, trauma to the eye, low blood calcium levels, exposure to toxins, radiation, electric shock, or an underlying medical condition. On rare occasions, young kittens can get cataracts as a result of a hereditary condition.
Symptoms of Cat Cataracts
In addition to looking for a cloudy haze or a bluish crystal-like shape over the pupils, paying attention to any change in habits can indicate vision problems caused by cataracts. These changes may include:
- Abnormal or staggered walking
- Tripping or bumping into things
- Misjudging distance when jumping
- Hesitant to use stairs
- Squinting
- Not recognizing familiar people
If a cataract only forms over one eye, there might be little or no sign of impairment, aside from the visible changes to the lens.
Diagnostic Tests for Cataracts
There are a variety of tests a veterinarian can perform to check for cataracts, ranging from simple to extensive:
- Menace Reflex – moves a hand quickly towards the cat’s face to study the reaction
- Cotton ball test – throws a cotton ball on the floor to see if its movement is followed
- Intraocular pressure test – tests for glaucoma by checking the pressure within the eye
- Schirmer tear test – checks the moisture level of the eye
- Fluorescein dye eye stain – used to detect any foreign material in the eye
Once the diagnosis of cataracts has been confirmed, blood tests will usually be performed to check for any medical conditions that could cause the condition. If surgery is suggested, more advanced tests, such as ocular ultrasonography and electroretinography, will be done.
Treatment for Cataracts in Cats
Occasionally, such as when caused by malnutrition or occurring in kittens, treatment might not be required. Cataracts due to poor nutrition may be slowed or stopped with nutritional supplements and the condition could simply disappear in young kittens. In most cases, however, the only effective form of treatment will be a surgical procedure to have the affected lens removed with phacoemulsification, a process that causes ultrasonic fragmentation of the lens. An artificial lens is then put in its place.