Longitudinal Assessment of the Choroidal Vascularity Index in Eyes with Branch Retinal Vein Occlusion-Associated Cystoid Macular Edema.

Our study evaluated a novel ocular optical coherence tomography imaging metric, the choroidal vascularity index, in eyes that developed cystoid macular edema, a condition which can significantly impair acuity of central vision, after being diagnosed with branch retinal vein occlusion. In each patient, we compared the choroidal vascularity index in eyes that developed treatment-naïve, newly diagnosed branch retinal vein occlusion with cystoid macular edema to the non-diseased fellow eye. We made comparisons at the time of diagnosis (baseline) and at the 12-month follow up, and analyzed changes over time. We found that at the baseline visit, branch retinal vein occlusion eyes with cystoid macular edema had a significantly lower choroidal vascularity index than their unaffected fellow eyes, but that the differences between eyes resolved by the 12-month follow-up visit. Our findings suggest that choroidal vascularity may be compromised in the acute phase of branch retinal vein occlusion, but that this phenomenon resolves over time. Future research should further evaluate whether imaging characteristics of choroidal vascularity may be associated with changes in anatomic and visual outcomes in retinal diseases.