AIMS

To establish rates of HLAB27-positive uveitis and ankylosing spondylitis in a New Zealand population and to examine characteristics of patients with ankylosing spondylitis that present with uveitis.

METHODS

A retrospective audit of 124 consecutive patients presenting to the Acute Eye Clinic at Auckland City Hospital with a diagnosis of either bilateral uveitis or their second episode of uveitis was undertaken. All patients underwent full blood count, erythrocyte sedimentation rate, HLAB27 typing, and radiographs of the sacroiliac joints and lumbar spine.

RESULTS

The HLAB27 antigen was detected in 36% of patients undergoing uveitis screening tests. Ankylosing spondylitis was diagnosed on lumbar spine and sacroiliac joint X-ray in 41% of HLAB27-positive patients and in none of the HLAB27-negative patients. No correlation was identified between age at first presentation and diagnosis of ankylosing spondylitis. Ankylosing spondylitis was not associated with elevated white cell count or erythrocyte sedimentation rate. Male gender and detection of the HLAB27 antigen were strongly associated with a diagnosis of ankylosing spondylitis (p<0.001).

CONCLUSIONS

Ankylosing spondylitis was detected in 41% of the HLAB27-positive patients and in 0% of the HLAB27-negative patients. Routine lumbar spine and sacroiliac joint X-rays are only recommended for HLAB27-positive patients.