Rheumatoid arthritis is an autoimmune disorder that affects your joints. The immune system mistakenly attacks the tissue that lines your joints, which leads to painful swelling that can destroy the bones. Typically, the hands and feet are affected, though any joint can be destroyed. Surprisingly, this disease can also impact other parts of your body, like your eyes. One of the many ocular complications of rheumatoid arthritis is scleritis; here are four things you need to know about it.

What is scleritis?

Scleritis is an inflammatory disease that affects your sclera, the white tissue on the outside of your eyeball. It lies just beneath the conjunctiva, the clear tissue that lines your eye. This disease is very serious as the inflammation can lead to vision loss.

What are the signs of scleritis?

The primary symptoms of scleritis are pain and redness of the eye. The redness gets worse over several days and eventually takes on a vivid, blue-red color. Patients describe the pain as a severe, stabbing pain that radiates to other areas of the face. The pain can be bad enough to wake you up in the middle of the night, and it's only temporarily improved by painkillers.

In addition to this severe pain, your eyes may be watery and you may not be able to look at bright lights without discomfort. Blurred vision may also occur if the inflammation spreads to other structures within the eye.

How does rheumatoid arthritis cause scleritis?

Rheumatoid arthritis and eye problems seem unrelated at first, but there's a simple explanation for the connection. Rheumatoid arthritis targets collagen, a connective tissue that lines the insides of your joints. Collagen isn't just found inside your joints, though; it is also the main component of your sclera. Since your sclera is almost entirely collagen, your immune system targets it, just like it targets your joints.

While not everyone with rheumatoid arthritis develops scleritis, it's pretty common. Between 4% and 10% of people with rheumatoid arthritis develop either scleritis or episcleritis (a closely related condition). Between 18% and 33% of scleritis cases are caused by rheumatoid arthritis, which makes it the most common cause of this eye disorder.

How is scleritis treated?

Your optometrist will treat the inflammation with non-steroidal anti-inflammatory drugs. If these medications don't work, stronger anti-inflammatories, like corticosteroids, can be used. In severe cases, systemic immunosuppressive medications can be used to control the inflammation.

If you have rheumatoid arthritis and your eyes are very sore and red, see your optometrist immediately. Make an appointment with an eye clinic, such as the Kennedy Eye Clinic, for more information.