Fig 1.
The choroidal vascularity index (CVI) measuring process with swept-source optical coherence tomography.
The total choroidal area (TCA) was determined using the polygon selection tool in ImageJ software (A). Following image binarization using the Niblack auto local threshold tool, the stromal area (SA) within the selected TCA was highlighted. A distinction was set between the SA (the yellow part) and the luminal area (LA; the black part) (B). The CVI was calculated as the ratio of LA to TCA.
Fig 2.
The choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) were measured to compare the branch retinal vein occlusion (BRVO), unaffected fellow, and post anti- vascular endothelial growth factor (VEGF) injected BRVO eyes.
(A) The CVI of the BRVO eyes was significantly decreased compared to the unaffected fellow and post-injected eyes (all p<0.05). (B) The SFCT of the post anti-VEGF injected eyes was significantly decreased compared to the BRVO eyes (p<0.05), with no significant change between the BRVO and unaffected fellow eyes found (p = 0.447; Wilcoxon matched-pairs signed-rank test).
Table 1.
Demographics, characteristics and choroidal measurements of the study subjects.
Fig 3.
The linear regression analysis between the choroidal parameters and logarithm of the minimum angle of resolution scale (logMAR) visual acuity measured two years post the disease onset.
The correlation between the choroidal vascularity index (CVI) of unaffected fellow eyes and the central macula thickness (CMT) of BRVO eyes. The R2 and p-values are presented. (B) The CVI of unaffected fellow eyes reveal the most prominent correlation value and a significant p-value; (A), (C) With the significant p-values, remarkable correlations are presented in the CVI and subfoveal choroidal thickness (SFCT) of the eyes with BRVO. (D) The CVI of unaffected fellow eyes shows a significant association with the CMT of diseased eyes.
Table 2.
Univariate regression analysis results.