QUANTITATIVE ANALYSIS OF STRUCTURAL ALTERATIONS IN THE CHOROID OF PATIENTS WITH ACTIVE BEHÇET UVEITIS.

Purpose: To quantitatively analyze in vivo morphology of subfoveal choroid during an acute attack of Behçet uveitis.

Methods: In this prospective study, 28 patients with Behçet uveitis of ≤4-year duration, and 28 control subjects underwent enhanced depth imaging optical coherence tomography. A novel custom software was used to calculate choroidal stroma-to-choroidal vessel lumen ratio. Subfoveal choroidal thickness was measured at fovea and 750 μm nasal, temporal, superior, and inferior to fovea. Patients underwent fluorescein angiography and indocyanine green angiography. Receiver operating characteristic curve and area under the curve were computed for central foveal thickness. The eye with a higher Behçet disease ocular attack score 24 was studied. The main outcome measures were choroidal stroma-to-choroidal vessel lumen ratio and choroidal thickness.

Results: The mean total Behçet disease ocular attack score 24, fluorescein angiography, and indocyanine green angiography scores were 7.42 ± 4.10, 17.42 ± 6.03, and 0.66 ± 0.73, respectively. Choroidal stroma-to-choroidal vessel lumen ratio was significantly higher in patients (0.413 ± 0.056 vs. 0.351 ± 0.063, P = 0.003). There were no significant differences in subfoveal choroidal thickness between patients and control subjects. Choroidal stroma-to-choroidal vessel lumen ratio correlated with retinal vascular staining and leakage score of fluorescein angiography (r = 0.300, P = 0.036). Central foveal thickness was significantly increased in patients (352.750 ± 107.134 μm vs. 263.500 ± 20.819 μm, P < 0.001). Central foveal thickness showed significant correlations with logarithm of minimum angle of resolution vision, Behçet disease ocular attack score 24, total fluorescein angiography score, retinal vascular staining and/or leakage and capillary leakage scores of fluorescein angiography, and total indocyanine green angiography score. At 275 μm cutoff, diagnostic sensitivity and specificity of central foveal thickness for acute Behçet uveitis were 89% and 72%, respectively (area under the curve = 0.902; 95% CI = 0.826-0.978, P < 0.001).

Conclusion: There was choroidal stromal expansion which was not associated with thickening of the choroid. Central foveal thickness may be used as a noninvasive measure to assess inflammatory activity in early Behçet uveitis.