Abstract
Purpose :
Retinal sheathed vessel (SV) was often observed in cases with branch retinal vein occlusion (BRVO) during the chronic phase. However, the clinical significance of SV is still unclear. The current study aimed to anatomically and functionally investigate retinal SV and characterize it in eyes with BRVO.
Methods :
One hundred nine cases with BRVO were reviewed retrospectively. The appearance of SV was evaluated based on fundus photograph on eyes with at least 1-year follow-up. Fluorescein angiography and optical coherence tomography (OCT) were used to examine the retinal status, (i.e., classification of ischemic and non-ischemic BRVO and major and macular BRVO). OCT angiography (OCTA) (AngioVue, RTVue XR, Optovue, USA) was used to detect blood flow in the lumen of SV and measure the vessel and flow diameter of SVs.
Results :
SV was detected in 45 (41%) of 109 eyes with a mean follow-up period of 26 months and often observed at the artery-vein (AV) crossing site (37 eyes, 82%). Multivariate analysis showed ischemic BRVO is a significant risk factor for the development of SV (80 % of eyes with SV and 25% of eyes without SV; odd ratio, 6.88; 95% confidence interval, 2.00-28.5; p=0.0018). From 28 of 45 eyes, 40 SVs were identified and analyzed by OCTA. Fifteen (35%) SVs had no flow. Twenty-five (65%) SVs had a flow, despite the lumen of vessels was attenuated (Fig 1). Average vessel diameter was 89.1 ± 5.8 μm and average flow diameter was 25.7 ± 4.1 μm. There was no difference in vessel diameter between with and without blood flow in all SVs. However, in SVs without AV crossing site, vessel diameter was significantly smaller in vessels without blood flow compared to the vessels with blood flow (41.5 ± 13.5 μm vs 86.0 ± 31.6 μm, p=0.0148) (Fig 2).
Conclusions :
Our results suggest that the SV was associated with retinal ischemia. SVs were often observed in AV crossing sites or small diameter vessels. SVs were usually observed can be fully or partially dysfunctional. SV might be a good indicator of ischemic BRVO in the chronic phase.
This is a 2020 ARVO Annual Meeting abstract.