Medical Ophthalmology: Case four

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This 45 year-old man who had a history of bilateral recurrent iritis was admitted to hospital with bloody diarrhoea of four day duration.

a. What does the X-ray show?

The X-ray shows two physical signs:

• grossly dilated colon. This is caused by toxic megacolon secondary to ulcerative colitis
• advanced syndesmophytes caused by ankylosing spondylitis giving a picture of "bamboo spine"

b. Which halotype is most likely to be positive?

HLA-B27 halotype (a particular set of HLA genes an individual carries on chromosome 6).
HLA-B27 is increased in patients with ulcerative colitis and ankylosing spondylitis. In the later, 90% of patients is positive for this halotype.

c. What ocular conditions are associated with these conditions?

Non-granulomatous anterior uveitis is the most common ocular complication in both conditions. In ulcerative colitis, this is about 10% whereas in ankylosing spondylitis the incidence is higher at 25%.

In ulcerative colitis, the following conditions have also been reported:

• episcleritis/scleritis
• conjunctivitis
• retinitis
• optic neuritis
• increased incidence of retinal vein occlusion due to hypercoagulopathy