Defining Cherry Eye in Cats
“Cherry eye” is the common name for a condition in cats where the gland of the third eyelid pops out of place and can be seen protruding from the inner corner of one or both of a cat’s eyes.
Unlike people, who have two eyelids, cats have three. Their third eyelid, called the nictitating membrane, is a thin sheet of tissue that normally is well-anchored to surrounding tissue and is not visible.
It functions to protect and moisturize the eyeball (globe of the eye) (eyeball), in part by contributing to tear production through a gland on the inside of the membrane. Cherry eye happens when the gland of the third eyelid becomes everted, or flips over – basically turning inside out.
When this occurs, the gland becomes highly prominent, appearing as a bright red mass bulging from the inside corner of the cat’s eye(s).
Causes & Prevention of Cherry Eye in Cats
Causes of Cherry Eye in Cats
Cherry eye is fairly rare in domestic cats. When it does occur, it involves eversion or prolapse of the gland of one or both of the cat’s third eyelids (also called the nictitating membranes).
Those glands are intimately associated with and located underneath the third eyelid, and usually they can’t be seen. They normally contribute up to fifty percent of the soothing, lubricating liquid that makes up a cat’s tears.
Tear film is important to protect the cornea and other eye structures and to keep the eye surface moist. When the gland of the third eyelid becomes exposed, it no longer produces and secretes its normal contributions to tear film.
What actually causes the gland to flip over and pop out at the inner corner of the affected eye is not well-understood. Many authorities believe that cherry eye happens as a result of some weakness in the fibrous connective tissues that are supposed to firmly anchor the third eyelid/nictitating membrane to the cat’s eyeball (also known as the periorbita or globe of the eye).
This weakness may have a hereditary component, and it may or may not be congenital (which means that it may or may not exist at the time the cat is born).
Preventing Cherry Eye in Cats
At the present time, there are no reported medical or surgical procedures that can prevent the occurrence of cherry eye in cats (or in other companion animals) without the risk of serious adverse side effects.
Certainly, the gland of the third eyelid can be surgically removed, which used to be the recommended treatment protocol. However, because that gland is responsible for producing so much of a cat’s tear film, taking it out markedly increases the animal’s risk of developing “dry eye” (keratoconjunctivitis sicca) as it ages.
If the gland of the third eyelid is removed, the cat will require life-long treatment with moisturizing topical eye drops and anti-inflammatory medication to prevent the pain and discomfort accompanying the dry eye condition.
Surgical correction by repositioning and permanently suturing the third eyelid to underlying tissue is the current treatment of choice for cats with cherry eye and is the best way to prevent repeated incidents. Many cats will have to go through a series of surgical procedures to fix the problem, in one eye at a time.
If an owner thinks that her cat may have developed cherry eye in one or both eyes, she should take it to the veterinarian as soon as possible. This condition can be uncomfortable and become painful as the gland of the third eyelid starts drying out and tear production is compromised.
Any unusual discharge coming from the affected eye or eyes can be gently removed with a soft tissue moistened with warm water.
Symptoms of Cherry Eye in Cats
Effects of Cherry Eye – From the Cat’s Point of View
Cherry eye is a fairly uncommon condition in companion cats. It occurs when the gland underlying one or both of a cat’s third eyelids – medically referred to as the “nictitating membranes” – everts or flips over, exposing it to environmental conditions.
Cherry eye occurs suddenly and rarely happens in both of a cat’s eyes at the same time. This condition can be extremely uncomfortable, irritating and painful. As the gland dries out from exposure to the elements, it makes less and less of the tear film that it normally produces to coat, sooth and protect the eye.
This causes the cat’s affected eye or eyes to become dry and scratchy. The discomfort and pain worsen with time. If not treated, cherry eye can eventually cause the cat’s cornea to ulcerate.
Symptoms of Cherry Eye – What the Cat’s Owner Sees
In cats as in dogs, the gland of the third eyelid normally doesn’t slip out of place gradually. It pops out remarkably quickly. Owners are understandably shocked to see a bright red, doughy mass of tissue protruding from the inner corner of one of their cat’s eyes, which looked completely normal just a few moments earlier.
Most of the time, this fleshy tissue mass is the only thing the owner notices. Other signs of cherry eye may include one or more of the following:
- Eye redness and inflammation (conjunctivitis; uveitis)
- Swelling around the eyes
- Excessive tear production (ocular discharge)
- Rubbing the eyes or face on the ground or furniture, or with the paws
- Excessive blinking
The cat can develop additional and sometimes serious complications if cherry eye is not corrected. The primary function of the third eyelid is to moisturize and physically protect the eye – particularly the cornea.
The gland of the third eyelid produces much of the fluid that makes up tears. When the gland of the third eyelid prolapses and becomes exposed to the outer world, the affected eye rapidly gets red, dry, irritated and inflamed due to environmental exposure and insufficient tear production.
There may be abnormal discharge coming from the affected eye as well. Some cats will rub or scratch at their eyes, which can damage the eyelids and possibly injure the corneas.
Cats at Increased Risk
Some cat breeds, including the Burmese and the Persian, are predisposed to developing cherry eye. This strongly suggests that there is a hereditary link to the condition. There is no known gender predisposition.
Cherry eye can look horrible. Fortunately, it usually can be treated with medication and surgery. If you think that your cat may have cherry eye, make an appointment with a veterinarian as soon as possible.
Cherry eye isn’t a life-threatening condition, but it still should be treated promptly to prevent permanent eye damage.
Diagnosing Cherry Eye in Cats
Cats and dogs both have a nictitating membrane (also called a third eyelid) in each eye. The third eyelid normally functions to provide physical protection to the cornea and to produce a significant portion of moisturizing tear film to keep the eyes well-lubricated.
Cherry eye is the most common disorder of the feline third eyelid. It is especially prevalent in certain breeds, such as the Burmese and Persian. Fortunately, this condition is not particularly common in cats, nor is it difficult to diagnose.
Owners who notice a doughy red mass of tissue that suddenly pops out from the inner corner of one or both of their cat’s eyes should take their pet to a veterinarian as soon as possible.
Cherry eye isn’t a medical emergency, but it still is important to treat the condition promptly to prevent permanent ocular damage. The initial discovery and evaluation of cherry eye is almost always first made by the cat’s owner.
Cherry eye is usually diagnosed based simply on the veterinarian’s physical examination of the animal, because it is so obvious and virtually impossible to ignore. In young cats, no special tests are needed to confirm that the gland of the third eyelid has prolapsed or everted, especially if the condition came on suddenly, which almost always is the case.
Older cats that gradually develop fleshy red masses in or around one or both of their eyes are more likely to be suffering from some form of cancer. In those cases, the veterinarian probably will recommend taking a biopsy of the mass and submitting the sample to a pathology laboratory, to determine exactly what it is.
Sometimes, the veterinarian will take an excisional biopsy, which involves removing the entire mass rather than removing only a small slice of it. A less invasive diagnostic tool is taking a sample using a fine needle aspirate (FNA).
This technique involves piercing the lump with a sterile needle attached to a syringe and pulling back on the plunger to extract cells and fluid. The contents of the syringe are then expressed onto a glass slide and examined under a microscope.
Any abnormal eye condition merits a thorough ophthalmic examination. This involves assessing the cat’s pupillary light reflexes, evaluating the size of its eyeballs, retropulsing the eyeballs and evaluating intraocular pressure (the pressure inside the eyeballs).
The cat’s demeanor, hydration status and overall body and coat condition will be evaluated as part of the physical examination. Advanced diagnostic techniques, including ultrasound, computed tomography (CT) scan and magnetic resonance imaging (MRI), are available at specialized referral centers and veterinary teaching hospitals but aren’t often used to diagnose eye problems.
Fortunately, diagnosing cherry eye is simple. Surgical correction of the condition is also fairly simple and usually is quite successful.
Treatment of Cherry Eye in Cats
Goals of Treating Cherry Eye in Cats
Prolapse of the gland of the third eyelid (the nictitating membrane), commonly called “cherry eye,” should be treated as quickly as possible. The condition is not particularly dangerous, but correction is important to make the cat comfortable and reduce the risk of more serious secondary eye problems.
The longer that the gland remains out of place exposed to environmental elements, the more likely it is to become irritated, inflamed, dry and possibly infected. The goals of treating cherry eye in cats are to:
- Return the function and appearance of the third eyelid and related structures to as normal a state as possible
- Reduce abnormal discharge from affected eye(s)
- Minimize irritation and injury to the cornea and conjunctiva
- Preserve and promote tear production
- Reduce the risk of secondary bacterial infections
- Eliminate discomfort
Treatment Options for Cats with Cherry Eye
Cherry eye can be treated with drugs, manual manipulation and/or surgery. Topical and oral medications can relieve discomfort, reduce inflammation and prevent or resolve the secondary bacterial eye infections that commonly accompany this condition.
However, drug treatments alone rarely resolve cherry eye permanently. Some veterinarians try to reposition the third eyelid back into place manually before resorting to surgery, although this isn’t a conventional treatment.
Manual manipulation of the gland only takes a few minutes and apparently is painless. Unfortunately, this technique typically doesn’t provide a permanent solution.
In most cases, cherry eye needs to be corrected surgically. At one time, the treatment of choice was to remove the prolapsed gland. However, because the third eyelid gland is responsible for producing a large part of the tear fluid, removing it markedly increases a cat’s risk of developing chronic “dry eye” (keratoconjunctivitis sicca) as it ages.
Those cats will require life-long daily treatment with topical eye drops and anti-inflammatory medication to keep their eyes moisturized and pain-free. Today, most veterinarians recommend surgically repositioning rather than removing the third eyelid gland in animals with cherry eye.
There are several different repositioning techniques, each of which should result in a cosmetically acceptable outcome with a low chance of recurrence if performed properly.
Some considerations are the ease of the procedure, its potential effect on future tear production, the chances of re-prolapse and the expected cosmetic results. Surgical correction of one eye won’t reduce the risk of cherry eye developing in the other.
If you think that your cat has cherry eye, try not to touch or manipulate the protruding red tissue mass. Also, don’t try to reposition the third eyelid, because it is possible that you might cause permanent damage to it or to other associated eye structures.