Keeping Your Eyes Healthy With Ankylosing Spondylitis

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On April 27, 2025

Some 20 to 30 percent of people with ankylosing spondylitis develop uveitis at some point. Anterior uveitis, which affects the front parts of the eye, accounts for 90 percent of those cases.

Different types of uveitis affect different parts of the eye, and some are more sight-threatening than others:

Anterior uveitis: Also known as iritis, anterior uveitis causes inflammation in front of the lens and behind the cornea.
Intermediate uveitis: This mainly develops in the jellylike substance in the middle of the eye, called the vitreous. While severe vision loss is uncommon, visual impairment can occur.
Posterior uveitis: This type affects the retina, choroid, and optic nerve, and it can lead to permanent vision loss.
Panuveitis: This affects the front, middle, and back of the eye similarly.

James T. Rosenbaum, MD, chair emeritus of the Legacy Devers Eye Institute and member of the Spondylitis Association of America’s Medical and Scientific Advisory Board, says that anterior uveitis has specific characteristics in people with AS.

“With AS, the uveitis is usually anterior and sudden in onset. This results in a red, painful eye that is sensitive to light,” says Dr. Rosenbaum. “Patients with recurrent episodes of anterior uveitis often report a vague sensation that something with the eye is amiss 12 to 24 hours before the eye becomes red.”

He also notes that uveitis is an essential early cue that you should look into whether you might have AS, especially if you have other symptoms that could be explained by AS.

“Uveitis is often the first symptom to prompt the recognition that chronic back pain or a swollen joint or tendon might be part of the AS spectrum,” says Rosenbaum. “If the uveitis began suddenly with redness, pain, and light sensitivity in one eye and then responded promptly to therapy with eye drops, the likelihood of associated AS is especially high.”

Christine Anastasiou, MD, clinical assistant professor in the division of immunology and rheumatology at Stanford Medicine, says that if you have uveitis and the following coinciding symptoms, your doctor may want to explore AS testing:

Chronic lower back pain that started before age 45, improves with exercise but not with rest, and persists for more than three months
Morning stiffness in the back or hips that lasts more than 30 minutes
Reduced flexibility or mobility in the spine or hips
A family history of nonradiographic axial spondyloarthritis, psoriasis, or inflammatory bowel disease
Joint pain, swelling, or stiffness in the hands and feet

Researchers have found specific genes with links to both ankylosing spondylitis and uveitis. People who develop uveitis and those with AS often share a genetic marker called HLA-B27.

Another genetic marker with potential links to both conditions may include ERAP1, according to the most recent data available.

These genetic markers may interact in ways that lead to inflammation in different areas of the body.

Rosenbaum explains that testing for HLA-B27 is insufficient for predicting uveitis. “We can test for genes that predispose to uveitis, such as HLA-B27, and we know that local trauma can also trigger an attack,” he says. “But currently, we lack a perfect way to predict who will develop uveitis or when that attack will begin.”

“Although genes like HLA-B27 are strongly linked to AS and uveitis, many people with HLA-B27 never develop the disease,” adds Dr. Anastasiou. “People with a family history of AS are at higher risk to develop AS and associated uveitis.”