05 February 2019
Purpose: To investigate retinal and choroidal microvascular changes and structural choroidal involvement in retinal vein occlusion (RVO). Methods: Retrospective analysis of treatment-naïve macular edema secondary to RVO, studied by optical coherence tomography (OCT) and OCT angiography (OCTA), before and after the loading phase of intravitreal injections of ranibizumab (IVR-LP). OCTA was performed using two different devices: AngioVue RTVue XR Avanti (spectral-domain OCTA) and Zeiss PLEX® Elite 9000 (swept-source OCTA). Results: 30 eyes of 30 consecutive patients (17 branch and 13 central RVO) were included. Central macular thickness and subfoveal choroidal thickness (SCT) were significantly reduced after IVR-LP ( p < 0.001 and p = 0.046, respectively). 23 eyes were eligible for OCTA analysis. Baseline vessel density (VD) in deep capillary plexus (DCP) was significantly reduced in RVO eyes compared with fellow eyes ( p = 0.03 and p = 0.002 for PLEX® Elite and AngioVue, respectively). After IVR-LP, no significant VD changes in any vascular layer was found. PLEX® Elite VD analysis showed significant differences in DCP between ischemic versus non-ischemic eyes ( p = 0.011). Conclusion: OCTA suggests a retinal vascular impairment of DCP but no involvement of choroid in RVO eyes. A greater baseline SCT could be due to a choroidal exudation. OCTA imaged with PLEX® Elite allowed to differentiate ischemic and non-ischemic patients at baseline.