Eye Inflammation, Uveitis and Ankylosing Spondylitis
Although ankylosing spondylitis (AS) is most known for its effects to the joints in the spine, the chronic inflammation can also affect other parts of the body, including the eyes. Inflammation of the eyes is one of the most common extra-articular (beyond the joint) manifestations of AS.1,2
Inflammation in the eye that occurs in the uvea (the middle layer of the eye) is called uveitis (pronounced you-vee-eye-tes). The front (anterior) uvea includes the iris (the colored part of the eyes), and inflammation in the anterior uvea may also be called iritis.1,2 It is estimated that 90% uveitis associated with AS is anterior uveitis, with only 10% being posterior (the back of the eye) uveitis.3
How does ankylosing spondylitis cause uveitis?
AS causes chronic inflammation in the body, and the inflammation may extend to one or both eyes. Several studies have found an association between the HLA-B27 antigen and uveitis. HLA-B27 is a common genetic marker in many (but not all) people with AS. In addition, uveitis is more common in people who have peripheral AS (that is, affecting joints in the arms or legs).1,3
How common is uveitis in people with ankylosing spondylitis?
Between 30-40% of people with AS will experience uveitis at some time during the course of their condition.1,2
What are the symptoms of uveitis?
The symptoms of uveitis may occur in one or both eyes and include2,4:
- Photophobia (sensitivity to light)
- Blurry vision
- Excessive tears
While some people may experience chronic eye symptoms, most cases of uveitis in people with AS are acute and symptoms occur suddenly. Because uveitis can be a serious condition and can result in permanent loss of vision if untreated. Anyone experiencing sudden eye symptoms should consult an eye doctor right away.1,2
How is uveitis diagnosed?
Diagnosis of uveitis is based on the patient's history (including the symptoms they are experiencing) and an eye examination. The eye examination frequently includes a slit-lamp examination, in which a microscope shines a narrow beam of light into the eye, allowing the ophthalmologist to view inside the eye. This is a painless test. The eyes may be dilated using drops prior to the slit-lamp examination.1,5