Choroidal Structural Changes in Patients with Birdshot Chorioretinopathy.

Purpose: To assess the choroidal vascularity index (CVI) in birdshot chorioretinopathy (BSCR) patients.Methods: The CVI was calculated as the ratio of luminar area to the total subfoveal choroidal area on enhanced-depth imaging optical coherence tomography. Intraocular inflammation was defined by the presence of macular edema and/or vitritis and/or vasculitis and/or papillitis.Results: Eighty BSCR patients and 22 healthy controls were included. Foveal choroidal thickness was lower in the BSCR compared with the control group (p < 0.001). CVI was not different between the two groups. CVI was significantly higher in BSCR patients with inflammatory activity (p = 0.004). Using a multivariate linear regression model, longer disease duration was associated with lower CVI (p = 0.038), whereas the presence of papillitis was associated with a higher CVI (p = 0.003).Conclusions: The CVI was not different between the BSCR and the control group. However, the CVI may be used as a new tool for monitoring inflammatory activity in BSCR.