The role of optical coherence tomography angiography in distinguishing ischemic versus non-ischemic central retinal vein occlusion

Abstract

Introduction: To observe macular microvascular changes in patients with ischemic and non-ischemic central retinal vein occlusion (CRVO) by optical coherence tomography angiography (OCTA), and explore the value of OCTA in differentiating ischemic and non-ischemic CRVO. Methods: Cross sectional study. Fifty patients diagnosed as CRVO with macular edema were included. Macular edema in all patients were regressive after three consecutive anti-VEGF treatment. Patients were divided into ischemic and non-ischemic group according to ultra-wide-angle fundus fluorescein angiography (UWFFA). All patients underwent BCVA, IOP, color fundus photography, UWFFA and OCTA. The following parameters were measured: (1) Vessel density (VD): superficial and deep whole VD (SVD, DVD), superficial and deep central fovea VD (SFVD, DFVD), superficial and deep parafoveal VD (SPFVD, DPFVD); (2) Central foveal retinal thickness (CRT); (3) Area of foveal avascular zone (FAZ), perimeter of FAZ (PERIM), avascular index of FAZ (AI) and VD within a width of 300 microns around the FAZ region (FD-300). Comparison between ischemic and non-ischemic group was performed by two independent sample t-tests. Receiver operating characteristic (ROC) curve analysis was used to measure the area under the curve (AUC) of VD for predicting ischemic CRVO. Results: There were no significant differences in IOP, SFVD, DFVD and CRT between ischemic and non-ischemic group, and significant differences in age, BCVA, SVD, SPFVD, DVD, DPFVD, FAZ area, PERIM, AI and FD-300 between ischemic and non-ischemic group. ROC curve analysis showed AUC of DVD and DPFVD in predicting ischemic CRVO was highest (0.962). the threshold was 38.40%, and the sensitivity was 100%, but the specificity of DVD (92.3%) was significantly higher than that of DPFVD (84.6%). Therefore, DVD ≤ 38.40% can be used as the best threshold for determining ischemic CRVO. Conclusion: OCTA can quantitatively evaluate the macular microvascular structure of CRVO, which is helpful to distinguish ischemic from non-ischemic CRVO.

Central and Peripheral Changes in Retinal Vein Occlusion and Fellow Eyes in Ultra-Widefield Optical Coherence Tomography Angiography

“…CRVO eyes exhibiting a deep capillary plexus (DCP) vessel density of ≤38.4% or retinal non-perfusion involving ≥10 disc areas in the acquired UWF-SS-OCTA images were categorized as ischemic CRVO. 18 , 19 The unaffected CRVO fellow and BRVO fellow eyes were also included. In addition, the healthy control group was comprised of 15 age-matched individuals without any ocular diseases (except for cataracts or non-pathologic myopia), with one eye randomly enrolled.…”

Role of optical coherence tomography angiography in the evaluation of peripheral ischemia in retinal vein occlusion

“…Nevertheless, a similar formula could be useful as a screening of patients at risk for ischemic CRVO while FA is of a high enough quality to allow objective assessment of the extension of ischemia. In a cross-sectional study from An et al .,[ 31 ] 50 eyes affected by acute CRVO and macular edema were evaluated with macular 3 mm × 3 mm OCTA and ultra-wide field FA (UWF FA) for ischemic areas assessment after 3 monthly injections of anti-vascular endothelial growth factor. Ischemic type was defined by the presence of ≥30 disk areas of retinal capillary nonperfusion on ultra-wide-angle fundus FA as per Central Vein Occlusion Study indications.…”

Clinical utility of ultra-widefield fluorescein angiography and optical coherence tomography angiography for retinal vein occlusions

“…Similar to how the definition of an “ischemic” RVO needs to be re-examined in UWF FA, some groups have attempted to try and re-define “ischemic” RVOs using OCTA, though this work is still in its initial stages. An et al performed a cross-sectional study on eyes with CRVO, where they classified them into ischemic or non-ischemic based on areas of non-perfusion on FA ( 78 ). They then showed that ischemic CRVOs had lower SCP and DCP vessel densities and larger FAZ area on 3 × 3 mm OCTA scans.…”