Choroidal thickness in non-ocular Behçet's disease – A spectral-domain OCT study

Purpose: To evaluate choroidal thickness in patients with non-ocular Behçet's disease (BD) using spectral domain optical coherence tomography (SD-OCT) and to compare the results to normal eyes. Methods: In this retrospective observational comparative study, we collected OCT and clinical data from the charts of 4 patients (7 eyes) with BD who had been referred for a screening eye exam and had a normal ocular examination. Data from 9 healthy volunteers (17 eyes) were collected as age-matched controls. The choroid was manually segmented from volume OCT scans using custom Doheny Image Reading Center OCT grading software (3D-OCTOR). Main outcome measures were choroidal thickness and intensity were compared between eyes of patients with BD and those of healthy controls. Results: Eyes of patients with non-ocular BD had significantly thinner mean central subfield choroidal thickness (227.5 ± 56.93 versus 306.85 ± 17.85, P = 0.04) and central subfield choroidal volume (0.18 ± 0.04 vs 0.24 ± 0.02, P = 0.005). There was no significant difference in mean choroidal thickness in the whole ETDRS grid or in mean choroidal intensity in the central subfield and the whole ETDRS grid between eyes of patients with non-ocular BD and those of controls. Conclusion: This study demonstrates that BD may have subclinical manifestations in the choroid, resulting in thinning of the choroid relative to normal eyes, even without overt signs of ocular involvement. Keywords: Choroidal thickness, Behçet's disease, Spectral domain optical coherence tomography, Choroidal intensity, Choroidal reflectivity