and Treating Acute Anterior Uveitis, Part 2
review of systems and laboratory testing can help uncover causes of acute anterior
uveitis (AAU). Most causes of AAU are idiopathic, however, laboratory tests may
reveal one of the
many systemic conditions that can bring about an AAU. Here we'll look at the top
seven causes of acute anterior uveitis to help in your differential diagnosis.
Searching for Answers
Juvenile rheumatoid arthritis
(JRA) occurs between ages 3 and 16, mostly in females. Tests include anti-nuclear
antibody (ANA), erythrocyte sedimentation rate (ESR) and X-rays of knees and other
affected joints. All will be positive. Females exhibit a more chronic, indolent
form of JRA. Screenings are suggested for all young females who have pauciarticular
arthritis and are also positive for ANA and negative for rheumatoid factor.
Fuchs heterochromic iridocyclitis
occurs at any age with no gender predilection. The iris heterochromia can be difficult
to ascertain, especially when bilateral. You will usually note keratic precipitates
scattered on the corneal endothelium with biomicroscopy. Laboratory testing is typically
(AS) typically occurs between age
15 and 40, in a greater percentage of men. Nearly a quarter of AS patients demonstrate
bilateral ocular involvement. Early in the disease, patients may complain of subtle
back pain. However, the hallmark of AS is severe back pain with restricted motion.
Radiographic laboratory findings after an anteroposterior view of the sacroiliac
joints will reveal heightened radiodense areas.
demonstrates the same age and gender predisposition as AS. It affects multiple systems,
which gives rise to polyarthritis, conjunctivitis, urethritis, skin eruptions and
oral ulcers. Like AS, laboratory tests such as HLA-B27 and ESR will be positive.
Other tests may include urethral cultures, WBC count, radiography and a Chlamydia
complement fixation test. Most cases of AAU are mild.
Testing for inflammatory bowel
disease can begin with an ESR and HLA-B27 testing. In conjunction with an
internist or gastroenterologist, other tests may include sigmoidoscopy, barium enema
and a rectal biopsy.
and tertiary forms of syphilis may produce AAU. Two common tests include
the VDRL and FTA-ABS. The VDRL becomes positive early in the disease course and
shows a 99 percent sensitivity in secondary syphilis cases. Although in cases of
late or latent syphilis, the sensitivity of VDRL decreases to 70 percent, an FTA-ABS
has a sensitivity of 98 percent. Eyecare practitioners typically order these tests
when they suspect syphilis-induced AAU. A lumbar puncture may also be ordered in
seropositive cases that have lasted for more than a year.
Nearly one-fifth of patients with
psoriatic arthritis (PA) will exhibit AAU. A positive HLA-B27 test
along with psoriasis and arthritis are indicative of psoriatic arthritis. Recent
work by Durrani and Foster (2005) indicates that psoriatic arthritis has distinct
clinical features not found in more common HLA-B27 causes of AAU. More often the
uveitis of psoriatic arthritis patients is bilateral, lasts longer and frequently
requires an oral NSAID therapy. The uveitis in PA may also occur at a later age,
corresponding with the increasing prevalence of psoriasis in older individuals.
A Look Ahead
Continued work in the area
of immunogenetics will aid in the diagnosis, future testing and possible
treatments of AAU in the years ahead.
Dr. Miller is
on the faculty at the University of Houston College of Optometry. He is a member
of the American Optometric Association and serves on its Journal Review Board. You
can reach him at firstname.lastname@example.org.
Contact Lens Spectrum, Issue: July 2005