More commonly seen in dogs, and sometimes rabbits, cherry eye is also occasionally a problem for cats. This disease affects the tissues surrounding the eye or eyes of a cat, but it can be more than just a cosmetic issue. Some cats are more prone to developing cherry eye than others, and it is important to know how to recognize it and what to do about it.
What Is Cherry Eye?
"Cherry eye" is actually a nickname for a medical condition called prolapsed nictitating membrane, prolapsed third eyelid, or third eyelid gland prolapse. The third eyelid, or nictitating membrane, is the fleshy, pink part next to the eye in the socket. It's actually a flap of tissue containing a gland that secretes tears. Usually it's not easily seen, and flattened against the corner of the eye socket. If it gets enlarged, flips over, and protrudes or prolapses, a cherry eye results.
Signs of Cherry Eye in Cats
A pink or red, fleshy protrusion coming from the inner corner of a cats eye is most likely a cherry eye. It is often described as a pink bubble or swelling and may be large enough to block part of a cat's eye. It can also come and go or be present permanently. Cherry eye in cats is quite obvious if you just know what to look for but the following secondary issues that cherry eye can cause are the real concerns.
Other symptoms include:
- Dry eye
- Corneal ulcers
- Inflammation of the cornea
- Inability to close the eyes
When cats develop dry eye, it's due to a lack of tear production. Since the third eyelid contains a gland that produces tears, this gland may not provide enough lubrication to the eye if it is inflamed and protruding. If an eye is dry it will become inflamed, feel irritated, and itch. An ulcer on the surface of the eye, called the cornea, can result. Dry eye, also known as keratoconjunctivitis sicca or KCS, may need to be treated habitually to avoid corneal ulcers. A corneal ulcer is very painful and can lead to permanent eye damage and even rupture if ignored.
If a cherry eye is large enough, it may also make it difficult or impossible for a cat to completely close its eyes. This is not only stressful and annoying to a cat, but it can also be a contributing factor for dry eye.
Causes of Cherry Eye
- Inflammation - Cherry eye is primarily due to the inflammation of the gland in the third eyelid. It swells up, turns inside out, and flips out in front of the eye.
- Size of the eye socket - Brachycephalic, or smushed face, cats may be born without enough room in their eye sockets to allow an enlarged or inflamed third eyelid gland to fit.
- Problems with the retinaculum - The retinaculum stabilizes the tendons that help hold the gland that causes cherry eye in place. Sometimes it is too weak to do its job and the gland pops out.
- Unknown - The reasons why some cats develop or are born with one or two cherry eyes is sometimes unknown.
Depending on the severity of the cherry eye, treatment may not even be necessary. But if the cherry eye is chronic and causing problems surgery might be recommended to correct the problem. Some cherry eyes will come and go on their own while others will pop out and stay out. In order to avoid secondary problems of a cherry eye, the gland will have to be put back into the eye socket very carefully. Manual, gentle pressure on the gland may replace it but often times it just comes back out. A special surgical procedure can tack the gland back into place in order to allow the gland to return to normal function and lubricate the eye.
If secondary problems have developed due to a cherry eye, special ointments or eye drops may need to be applied long term. There are also surgeries that may need to be performed. If a cherry eye is ignored for too long, it may not be able to be repaired. Occasionally, the gland will be removed if it is no longer serving its function of providing tears to the eye.
How to Prevent Cherry Eye
Unfortunately there is no real way to prevent cherry eye in cats. If a cat is born with a torn or weak retinaculum or a small eye socket, there is nothing you can do to prevent a cherry eye from happening.