Posterior scleritis and its association with HLA B27 haplotype.

BACKGROUND

Posterior scleritis is most commonly idiopathic but is also found in association with systemic disorders like rheumatoid arthritis. HLA B27 spondyloarthropathy manifests itself mainly in the form of anterior uveitis and anterior scleritis. Posterior scleritis has not been previously reported in patients with HLA B27 haplotype. We document the likely association between posterior scleritis and HLA B27 haplotype in a series of 5 patients who presented to the Ocular Inflammation and Immunology Services of the Singapore National Eye Centre.

METHODS

Retrospective observational case series. The medical records and ultrasound B scans of 5 patients with a diagnosis of posterior scleritis were reviewed.

RESULTS

The medical records of 5 patients (4 Chinese and 1 Malay) in the age range of 22-64 years were reviewed. All had unilateral disease (4 in the left eye and 1 in the right eye) at presentation. The most common presenting symptoms were pain (5) and blurring of vision (5); diplopia and proptosis was present in 2 patients. Two patients had anterior scleritis and all had an associated anterior uveitis. Posterior segment findings included optic disc edema (5), macular edema (5), choroidal folds (3), exudative retinal detachment (2) and choroidal effusion (1). All patients had a thickened sclera on serial ultrasound B scan. 2 patients had joint involvement preceding ocular signs and symptoms and were diagnosed to have ankylosing spondylitis. HLAB27 was positive in all our patients. Systemic workup for other diseases was negative. The ocular inflammation responded to a varying combination of topical, periocular and systemic steroids. One of them developed a recurrence of posterior scleritis which resolved with oral steroids. Visual outcome was satisfactory in all but 1 patient who had retinal pigment epithelium atrophy at the macula.

CONCLUSION

Although posterior scleritis has been reported in association with ankylosing spondylitis, it is not clear whether it is the HLAB27 haplotype that is associated with posterior scleritis or ankylosing spondylitis. All our patients were HLAB27 positive but 2 of them did not have an underlying spondyloarthropathy. This suggests the possible association of posterior scleritis with HLAB27 haplotype.