Choroidal change in acute anterior uveitis associated with human leukocyte antigen-B27

PURPOSE To evaluate choroidal changes in eyes with acute anterior uveitis associated with human leukocyte antigen (HLA)-B27. METHODS 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. RESULTS 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). CONCLUSIONS 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.