The sclera is the protective outer layer of the eye, which is also the white part of the eye. It’s connected to muscles that help the eye move. About 83 percent of the eye surface is the sclera.
Scleritis is a disorder in which the sclera becomes severely inflamed and red. It can be very painful. Scleritis is believed to be the result of the body’s immune system overreacting. The type of scleritis you have depends on the location of the inflammation. Most people feel severe pain with the condition, but there are exceptions.
Early treatment with medication is necessary to prevent scleritis from progressing. Serious, untreated cases can lead to partial or complete vision loss.
Doctors use what’s called the Watson and Hayreh classification to distinguish the different types of scleritis. Classification is based upon whether the disease is affecting the anterior (front) or posterior (back) of the sclera. The anterior forms are most likely to have an underlying illness as part of their cause.
The subtypes of anterior scleritis include:
- anterior scleritis: the most common form of scleritis
- nodular anterior scleritis: the second most common form
- necrotizing anterior scleritis with inflammation: the most serious form of anterior scleritis
- necrotizing anterior scleritis without inflammation: the rarest form of anterior scleritis
- posterior scleritis: more difficult to diagnose and detect because it has variable symptoms, including many that mimic other disorders
Each type of scleritis has similar symptoms, and they can worsen if the condition isn’t treated. Severe eye pain that responds poorly to painkillers is the main symptom of scleritis. Eye movements are likely to make the pain worse. The pain may spread throughout the entire face, particularly on the side of the affected eye.
Other symptoms may include:
- excessive tearing, or lacrimation
- decreased vision
- blurry vision
- sensitivity to light, or photophobia
- redness of the sclera, or white portion of your eye
The symptoms of posterior scleritis are not as evident because it does not cause the severe pain as other types. Symptoms include:
- deep-seated headaches
- pain caused by eye movement
- eye irritation
- double vision
Some people experience little to no pain from scleritis. This may be because they have:
- a milder case
- scleromalacia perforans, which is a rare complication of advanced rheumatoid arthritis (RA)
- a history of using immunosuppressive medications (they prevent activity in the immune system) before symptoms began
There are theories that the immune system’s T cells cause scleritis. The immune system is a network of organs, tissues, and circulating cells that work together to stop bacteria and viruses from causing illness. T cells work to destroy incoming pathogens, which are organisms that can cause disease or illness. In scleritis, they’re believed to begin attacking the eye’s own scleral cells. Doctors still aren’t sure why this happens.
Scleritis may occur at any age. Women are more likely to develop it than men. There’s no specific race or area of the world where this condition is more common.
You have an increased chance of developing scleritis if you have:
- Wegener’s disease (Wegener’s granulomatosis), which is an uncommon disorder that involves inflammation of the blood vessels
- rheumatoid arthritis (RA), which is an autoimmune disorder causing inflammation of the joints
- inflammatory bowel disease (IBD), which causes digestive symptoms due to inflammation of the bowel
- Sjogren’s syndrome, which is an immune disorder known for causing dry eyes and mouth
- lupus, an immune disorder that causes skin inflammation
- eye infections (may or may not be related to autoimmune disease)
- damage to eye tissues from an accident
Your doctor will review a detailed medical history and perform an examination and laboratory evaluations to diagnose scleritis.
Your doctor may ask questions about your history of systemic conditions, such as whether you’ve had RA, Wegener’s granulomatosis, or IBD. They may also ask if you’ve had a history of trauma or surgery to the eye.
Other conditions that have symptoms similar to scleritis include:
- episcleritis, which is an inflammation of superficial vessels in the outermost layer of the eye (episclera)
- blepharitis, which is an inflammation of the outer eye lid
- viral conjunctivitis, which is an inflammation of the eye caused by a virus
- bacterial conjunctivitis, which is an inflammation of the eye caused by bacteria
The following tests can help your doctor make a diagnosis:
- ultrasonography to look for changes occurring in or around the sclera
- complete blood count to check for signs of infection and immune system activity
- a biopsy of your sclera, which involves removing tissue of the sclera so that it can be examined under a microscope
Treatment of scleritis focuses on fighting the inflammation before it can cause permanent damage. Pain from scleritis is also related to inflammation, so reducing the swelling will decrease symptoms.
The treatment follows a stepladder approach. If the first step in medication fails, then the second is used.
Medications used to treat scleritis include the following:
- Nonsteroidal anti-inflammatory drugs (NSAIDs) are most often used in nodular anterior scleritis. Reducing inflammation also helps to ease scleritis pain.
- Corticosteroid pills (such as prednisone) may be used if NSAIDs don’t reduce inflammation.
- Oral glucocorticoids are the preferred choice for posterior scleritis.
- Immunosuppressive drugs with oral glucocorticoids are preferred for the most dangerous form, which is necrotizing scleritis.
- Antibiotics may be used to prevent or treat infections of the sclera.
- Antifungal medications are commonly used in infections caused by Sjogren’s syndrome.
Surgery may also be necessary for severe cases of scleritis. The process involves the repair of tissues in the sclera to improve muscle function and prevent vision loss.
Sclera treatment may also be contingent on treating the underlying causes. For example, if you have an autoimmune disorder, then effectively treating it will help prevent recurring cases of scleritis.
Scleritis can cause significant eye damage, including partial to complete vision loss. When vision loss does occur, it’s usually the result of necrotizing scleritis. There’s a risk that scleritis will come back despite treatment.
Scleritis is a serious eye condition that requires prompt treatment, as soon as symptoms are noticed. Even if your symptoms improve, it’s important to follow up with an ophthalmologist on a regular basis to make sure it doesn’t return. Treating underlying autoimmune conditions that might cause scleritis is also important in preventing future problems with the sclera.