The third eyelid is a membrane (nictitating membrane) found in the inner corner of cats' eyes. In addition to carrying out a protective function from possible injuries, it allows to keep the eyeballs healthy by increasing the production of tears and keeping the corneas (the transparent front part) moist thanks to the distribution of the tear film. Usually, this membrane is not visible, but it can sometimes protrude (come out) and remain everted due to several factors, including considerable weight loss or nerve damage. If you see the third eyelid protruding exaggeratedly from your cat's eyes, you need to take him to the vet for a visit.
Steps
Part 1 of 2: Check the Cat's Eyes
Step 1. Look at the cornea
When the third eyelid protrudes, you can see that it covers at least part of this tissue. Fortunately, this disorder does not automatically affect the cat's vision, as the membrane usually covers less than 50% of the cornea and the cat can still see relatively well.
If the cat has suffered an eye injury, the third eyelid of the injured eye may cover more cornea than the healthy eye
Step 2. Find an oval, pink mass on the animal's eyes
The nictitating membrane has its own specific lacrimal gland which helps to keep the cornea moist together with the other two eyelids (upper and lower). When the animal suffers from prolapse of the third eyelid - a disease also called "cherry eye" - the bond that holds this gland in place loosens and the pink-colored gland becomes protruding. The disorder can form in one or both eyes.
If you notice a pink mass in the corner of your cat's eye, it could be this disease
Step 3. Recognize the redness of the third eyelid
When healthy, this membrane is white or pale pink in color; when it is irritated, however, it turns red. If your cat has cherry eye, the protruding tear gland may be red due to irritation from dust or dust in the air.
Step 4. Pay attention to leaking secretions
Cherry eye can lead to the formation of a liquid discharge, the consistency of which varies according to the underlying cause of the disease. If the problem is the result of an infection, the material may be thick and mucus-like; when the origin is a weakening of the lacrimal gland bond, a clear and watery secretion develops.
The protrusion of the third eyelid by itself (without the protrusion of the lacrimal gland) may not cause secretions
Step 5. Make a note of when you notice the problem
This is not always an anomaly; for example, if the cat is sleeping soundly or sensing a possible threat to the eyes, the third eyelid may come out to protect them. In this case, eventually the membrane returns to its original position and the problem resolves itself spontaneously; however, if it stays out, it is a sign of something abnormal and you need to go to the vet.
Part 2 of 2: Getting a Diagnosis from the Vet
Step 1. Take your cat to the vet
Although it is easy to notice the protrusion of the third eyelid, it is important to define the cause and the doctor is able to do this. Before going to the appointment, Not give your cat any over-the-counter eye treatment, such as eye drops, because it is not very effective in domestic cats and can hinder making a correct diagnosis.
Step 2. Inform the veterinarian of the animal's medical history
It is always important to know the cat's medical background in order to make a proper diagnosis. During the visit, tell the doctor about your little friend's past or present health conditions; for example, if you have recently had an intestinal infection, the resulting inflammation may have damaged the nerve that controls the movements of the third eyelid, causing it to protrude.
- Also tell him when you first saw the protruding membrane.
- If your cat has lost a lot of weight, tell the doctor what diet they are following.
- If your vet already knows your cat's medical history, he or she can review the history already recorded to identify possible causes of the disease.
Step 3. Let the doctor analyze your eyes
In addition to a physical examination, the vet performs a thorough check of the eyes; there is a wide range of ophthalmic diagnostic tests:
- Examination of the protruded third eyelid through a small forceps: for this test it is necessary to first apply an anesthetic on the eyelid;
- Pupillary reflex - determines how the pupil reacts to light; when the vet points a small flashlight into the cat's eye, the pupil should narrow;
- Schirmer test: measures the amount of tears produced by the gland; it is performed by placing a thin strip in the third eyelid area for one minute, which soaks as tears are produced;
- Fluorescein examination of the tear film to identify corneal lesions. Fluorescein is a green dye that the vet applies to the cat's eyes, after which he turns off the lights to visualize their distribution;
- If the protrusion affects only one eye, the vet also checks the healthy one to make sure the disease is not becoming bilateral.
Step 4. Allow your doctor to investigate further
After carefully examining the cat's ocular health condition, he may want to examine the problem by other diagnostic means to determine the cause of the ejection. For example, a neurological study may be useful if there is a suspicion of a nerve or brain disorder; X-rays of the skull can rule out or confirm abnormalities of the orbit, as well as blood tests can provide a picture of the cat's general health and detect the presence of infections.
If the cat has an ongoing respiratory infection, the doctor might take a sample of fluid (nasal or eye secretions) for analysis under a microscope
Advice
- The third eyelid of cats works like the windshield wiper: it removes residue and redistributes the tear film on the cornea.
- The movement of the third eyelid is controlled by a small muscle located behind the eye and by the nerves located in the eye.
- Bilateral protrusion of the third eyelid (in both eyes) appears to affect only cats under the age of three and typically following a bowel problem.
- Nictitating membrane extroflexion is a common complaint among Persian and Burmese cats.
