Baseline subfoveal choroidal thickness as an indicator for bevacizumab outcomes in central retinal vein occlusion

Background: Retinal vein occlusions are one of the most common form of retinal vascular disorders and could lead to vision loss due to macular edema, macular ischemia and sequelae from neovascularization. Anti-venous endothelial growth factor (anti-VEGF) treatment is the choice strategy of treatment for patients with macular edema secondary to central retinal vein occlusion (CRVO). There is an evidence of body with the controversies regarding increment of choroidal thickness in CRVO condition. The current study was designed to determine whether baseline subfoveal choroidal thickness may be an indicator for visual and anatomical outcome of bevacizumab in patients with CRVO macular edema. Methods: This study was a prospective clinical cohort study that enrolled in 23 new cases of treatment-naïve central retinal vein occlusion (CRVO) from February to July 2017 who were visited in Feiz Eye Hospital, Isfahan, Iran. Patients received a single injection of bevacizumab and were followed for 30 days. Ratio of subfoveal choroidal thickness (SFCT) was measured using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT). Ratio of SFCT of the CRVO eye to the fellow healthy eye (SFCT1/F) was taken as independent variable. Changes of best-corrected visual acuity (BCVA) in LogMAR (ΔBCVA, functional response) and secondary to baseline central macular thickness ratio (CMT2/1, anatomical response) in the CRVO eyes were taken for comparative and correlative analytics. Results: A total of 46 eyes from 23 patients with the mean age of 64.60±10.19 years were included in this study. Baseline SFCT was higher in CRVO eyes (251.91±46.09 µm) in comparison to the fellow eye (206.95±26.62, P<0.0001). Also central macular thickness in CRVO eyes were significantly higher in CRVO eyes in comparison with fellow eye (531.04±38.22 vs 303.30±33.59, respectively, P<0.05). SFCT1/F, correlated moderately with anatomical (CMT2/1) and strongly with functional response (ΔBCVA). Conclusion: Bilateral evaluation of SFCT by EDI-OCT in all newly diagnosed CRVO cases is recommended to determine if there is a relative increase in choroidal thickness. This may help predict short-term response to anti-VEGF therapy.