Optical Coherence Tomography Angiography in Central Retinal Vein Occlusion: Macular Changes and Their Correlation with Peripheral Nonperfusion at Ultra-Widefield Fluorescein Angiography

Introduction: The aim of this study was to investigate the correlation between ischemic index (ISI) measured on ultra-widefield (UWF) fluorescein angiography (FA) images and macular parameters obtained by optical coherence tomography angiography (OCT-A) in eyes affected by central retinal vein occlusion (CRVO). Methods: Retrospective study of data from 12 eyes affected by treatment-naïve CRVO. All patients underwent a comprehensive ocular examination including structural OCT, OCT-A, and UWF FA. Variables analyzed included best corrected visual acuity (BCVA) measured with the ETDRS chart; foveal avascular zone (FAZ) area at full-thickness OCT-A angiogram; perfusion density (PD) in the superficial (SCP) and deep capillary plexus (DCP); ISI; and central macular thickness (CMT). Results: ISI showed a significant positive correlation with FAZ area (r = 0.63, p = 0.019) and a significant negative correlation with PD in the SCP (r = -0.62, p = 0.022), PD in the DCP (r = -0.66, p = 0.011), and BCVA (r = -0.75, p = 0.002). FAZ area also negatively correlated to PD in the SCP (r = -0.75, p = 0.002) and DCP (r = -0.64, p = 0.016). BCVA positively correlated to PD in the SCP (r = 0.67, p = 0.009) and DCP (r = 0.68, p = 0.008), while a negative correlation was found with FAZ area (r = -0.65, p = 0.013) and CMT (r = -0.70, p = 0.006). Discussion/Conclusion: OCT-A macular parameters (namely, FAZ area and PD of SCP and DCP) significantly correlated with ISI, a quantitative way to assess peripheral retinal nonperfusion on UWF FA. Macular OCT-A analysis may help in assessing the need for additional UWF FA testing in eyes affected by CRVO.