What Is Conjunctival Chemosis?

Medically Reviewed by Whitney Seltman, OD on May 30, 2023
5 min read

The conjunctiva is the clear membrane that covers the white part of the eye. Conjunctival chemosis is a swelling of the membrane. It can look like a big blister on the eyeball. The eyes may be yellowish and watery. Chemosis can get so severe that it is hard to close the eye. 

Although it can be unsightly, chemosis is usually easy to treat, although sometimes takes time to totally resolve.  Also, the condition is not contagious as some other eye conditions can be. The best solution is prevention. If you understand what causes chemosis, you may be able to avoid repeated episodes.

Allergies are the most common cause of conjunctival chemosis. Chemosis can develop after surgery on the eye. It can be caused by conjunctivitis, commonly known as pinkeye, and by a few other conditions. 

When allergies make the eyes red and swollen, the resulting condition is sometimes called allergic conjunctivitis. Studies suggest that around 40% of the population in developed countries may have this condition. The eye irritation can lead to chemosis. 

Typical allergy symptoms include:

  • Runny or stuffy nose
  • Itching
  • Excessive tears
  • Discharge from the eyes
  • A sensation of having something in the eye

When chemosis is triggered by allergies, doctors may treat the cause and the symptoms. They may suggest cold compresses and artificial tears to ease the symptoms of chemosis. To attack the cause, they may use antihistamines and other medicines that tamp down allergic reactions.

Another treatment involves the use of steroids. Some doctors are using steroids earlier in the course of chemosis. They want to stop what is called an inflammatory or allergic cascade, where one reaction leads to another and then to another.

The eye infection known as conjunctivitis, or pinkeye, can lead to conjunctival chemosis. Treating the conjunctivitis should make the chemosis go away. 

Some cases of pinkeye are bacterial, and some are viral. Bacterial conjunctivitis is treated with antibiotic eye drops. The usual course of treatment is 7 to 10 days. 

Viral conjunctivitis usually requires no treatment. Usually, the eyes will be better in a week or so. Antibiotic eye drops are not effective against a virus. The antiviral eye drops used for some other eye conditions do not work on pinkeye. 

It's difficult to distinguish between the two types of pinkeye, so some doctors routinely prescribe antibiotic ointments or drops. In severe cases of viral conjunctivitis, doctors may prescribe steroid drops.

Since both types are infectious, it's important to prevent them from spreading. To contain the infection, try these measures: 

  • Use hand sanitizer before treating the eye.
  • Clean the hands after touching one eye before touching the other.
  • Separate any towels and washcloths used in treatment from other laundry. 
  • Stay home from school or work if possible.

Chemosis can also follow eyelid surgery or other trauma to the eyelid. The most common cause is blepharoplasty – surgery to repair drooping eyelids. 

Certain conditions are risk factors for this type of chemosis. For example, chemosis may be more likely if the lower lid is slack or doesn't close well. Doctors may address some of these problems before they operate.

Chemosis can develop in the middle of surgery. Doctors can use certain surgical techniques to stop the chemosis during the surgery. They may use eye drops during the surgery to manage the chemosis.  

Some cases of chemosis appear after the surgery. They can be mild, moderate, or severe. Doctors treat them with drops, ointments, the use of an eye patch, and other measures. Sometimes the chemosis persists and further surgery is necessary.

Thyroid eye disease (TED) causes inflammation of the eyes and the tissues around the eyes, often resulting in chemosis. The usual cause of TED is  Graves' disease, an autoimmune disorder in which the body attacks its own tissues. Graves' ophthalmopathy is another term for TED.  

Graves' disease causes the body to produce too much thyroid hormone. Those with TED must control their thyroid levels carefully. Even when they do, they may still have eye problems. 

These problems may include:

  • Bulging eyeballs
  • Eyelids pulled away from the eyeballs
  • Swollen eye muscles
  • Pain with eye movement
  • Problems with the optic nerve 

Doctors evaluate the severity of TED by looking at seven signs or symptoms. Chemosis is one of those signs.

TED is mostly treated through lifestyle interventions. It is very important that those with TED not smoke and that they practice other good health habits. 

They can relieve some symptoms by wearing sunglasses and using treatments for dry eyes. They may ease swelling around the eyes by sleeping with the head elevated and by reducing sodium in the diet. Supplementing with selenium may also help.

Angioedema is an allergic reaction that usually occurs around the eyes or mouth. It causes swelling beneath the skin. When it forms around the eyes, it can trigger chemosis. 

Hives – large welts on the skin – can occur with angioedema. Both angioedema and hives usually clear up on their own. Treatment with antihistamines may ease the discomfort. Occasionally, parts of the mouth or throat will swell and interfere with breathing. This is an emergency calling for immediate medical care. 

Angioedema can be triggered by:

  • Foods – especially peanuts, soy, eggs, milk, fish, shellfish, wheat, and tree nuts
  • Medications – including blood pressure medicines, pain medications, anti-inflammatories, and penicillin
  • Airborne allergens such as pollen 

Other occasional triggers for angioedema include sunlight, tight clothing, exercise, hot water, and insect bites. 

If you have a conjunctival cyst, you may be able to see it. It looks like a clear blister or bubble on the eye. You may have extra tears and feel as if you have something in your eye. Sometimes, you might not notice any symptoms at all.

People who have conjunctival cysts often go to the doctor when they notice the cyst getting larger. The cyst may also become so noticeable that it is a cosmetic issue. Rarely, the cysts may cause blurred vision or affect how well your eyeball moves.

Causes of conjunctival cysts: Chemicals, allergies, and dry air can irritate the conjunctiva, leading to conjunctival cysts.

Conjunctival cyst treatment: Sometimes, conjunctival cysts go away on their own. Doctors often advise waiting to see if this happens. To make your eye feel better in the meantime, you can use:

  • Artificial tears or other lubricating drops
  • Prescription steroid drops to ease inflammation
  • Warm compresses, which may cause the cyst to break
  • Antibiotic ointment prescribed by a doctor, in case of infection

The simplest thing that your doctor can do is to drain the cyst. Doctors can also remove them but there is a chance they can come back. Another method for dealing with conjunctival cysts involves using plasma, an ionized gas produced by heating.