Date Published: June 28, 2017
Publisher: Public Library of Science
Author(s): Seong Joon Ahn, Ji Hong Kim, Byung Ro Lee, James T. Rosenbaum.
To evaluate choroidal changes in eyes with acute anterior uveitis associated with human leukocyte antigen (HLA)-B27
In 44 patients with first-onset, unilateral, acute-onset (<1 week) anterior uveitis for which diagnostic work-ups revealed positivity only for HLA-B27, wide-field three-dimensional volumetric raster scan using swept-source optical coherence tomography was performed for both eyes. Choroidal thickness was measured by automated segmentation and thickness mapping and compared between eyes with uveitis and the fellow eyes at baseline. Choroidal thickness was compared before and after topical and/or systemic corticosteroid therapy. Relative choroidal thickening was defined as the choroidal thickness of the uveitic eye minus that of the corresponding eye and correlated with the degree of intraocular inflammation. Compared to the fellow eyes, eyes with acute anterior uveitis showed significant choroidal thickening on the subfoveal and parafoveal areas at baseline (all P <0.05). En face choroidal imaging showed dilation of large choroidal vessels on the macula. Relative choroidal thickening significantly correlated with the degree of anterior chamber inflammation at baseline (correlation coefficient = 0.341, P = 0.023). After treating inflammation, the choroid on the macula thinned significantly (from 262.1 ± 66.5 to 239.5 ± 61.0 μm in the subfoveal choroid, P<0.001). Eyes with HLA-B27-associated anterior uveitis showed significant choroidal thickening at acute phase that subsequently decreased after treatment, indicating subclinical choroidal inflammation in the eyes. Choroidal thickness might indicate disease activity in acute anterior uveitis associated with HLA-B27.
Anterior uveitis is characterized by inflammation primarily in the anterior chamber, according to the Standardization of Uveitis Nomenclature Working Group (SUN). It is the most common type of uveitis, accounting for 50–90% of all uveitis diagnoses.[2, 3] Anterior uveitis can occur without any associated inflammation in other parts of the body or may be associated with systemic inflammatory disorders, including ankylosing spondylitis, sarcoidosis, interstitial nephritis, vasculitis, and inflammatory bowel diseases. In particular, it is most commonly associated with a tissue type known as HLA-B27.
The present study provides a detailed assessment of choroidal thickness in peripapillary and macular locations using SS-OCT, which enables better imaging of deeper structures, like the chorioscleral interface, than conventional spectral domain OCT. Using automated measurements, our study showed choroidal thickening on the macular area in eyes with acute anterior uveitis and a reduction in thickness after treatment. A dose-response relationship between relative choroidal thickening and the degree of anterior chamber inflammation further strengthen the association between anterior uveitis and choroidal thickening. Our study suggests that inflammation may be affecting the eye more widely than clinicians observe from biomicroscopic examinations.