Microvascular and functional changes according to the fundus location of the affected arteriovenous crossing in patients with branch retinal vein occlusion

Abstract

Purpose: The aim of this study was to evaluate the structural and functional changes occurring in patients with branch retinal vein occlusion (BRVO) according to the distance of the affected arteriovenous (AV) crossing to the centers of the fovea and optic disc by optic coherence tomography angiography (OCTA). Methods: Forty-five patients with unilateral BRVO and 45 age- and sex-matched healthy controls were included in this retrospective observational study. Images of the macula (3 mm × 3 mm) and affected AV crossing sites were obtained by OCTA. The fovea-AV crossing distance (FAVD), optic disc-AV crossing distance (DAVD), and optic disc-fovea distance (DFD) were measured. Results: The FAVD/DFD ratio was positively correlated with the vessel density in the superficial and deep affected hemifields ( r = 0.430, P < 0.05 and r = 0.308, P < 0.05, respectively) and negatively correlated with the superficial foveal avascular zone and logarithm of the minimum angle of resolution (logMAR) visual acuity ( r = –0.412, P < 0.05 and r = –0.356, P < 0.05, respectively). The DAVD/DFD ratio was not correlated with the logMAR visual acuity, superficial FAZ area or vessel densities in the affected hemifield (all P > 0.05). Conclusion: The affected AV crossing site that was further away from the fovea had better visual acuity and quantitative microvascular parameters in the affected hemifields. However, this correlation was not observed for the distance between the affected AV crossing site and the optic disc.

Linking Structure and Function: Image-Based Virtual Populations of the Retinal Vasculature

“…In particular, it was the sole parameter influencing VSD. This results confirms the hypothesis by 61 that branch geometry is correlated with VPI, which is twice VSD in Equation (8). The associations between structure and haemodynamics should be investigating further, perhaps with spatial metrics which can be compared with OCTA measurements 61 .…”

“…The pixel coordinates for each curve were extracted and translated so that the fovea is at the origin. This ensures that the model learns the distance between the optic disc and the fovea and between the arcades and the fovea, which may have importance in disease 8 . For images of right eyes, curves are reflected across the y-axis so that all shapes correspond to left eyes (i.e., the optic disc will be on the left-hand side of the image).…”

Linking Vascular Structure and Function: Image-Based Virtual Populations of the Retina

“…This ensures that the model learns the distance between the optic disc and the fovea and between the arcades and the fovea, which may have importance in disease. 39 For images of right eyes, curves are reflected across the y -axis so that all shapes correspond to left eyes (i.e., the optic disc will be on the left-hand side of the image). A simple principal component analysis–based statistical shape model learns the shape of all four temporal arcade vessels based on the location of inflexion points along the vessels (see Supplementary Material S1 ).…”

Potential Prognostic Indicators for Patients With Retinal Vein Occlusion

“…At baseline, the BCVA was negatively associated with the choriocapillaris flow area, the whole en face (3 mm × 3 mm) vessel density (VD), and the overall parafoveal VD in both the super capillary plexus (SCP) and deep capillary plexus (DCP) in the BRVO, but not in CRVO ( 82 , 83 ). A cross-sectional study combining OCT and OCTA images showed a significant negative correlation between logMAR VA and FAVD/DFD [the fovea–AV crossing distance (FAVD), optic disc–fovea distance (DFD)] values, but no correlation between logMAR VA and the DAVD/DFD [optic disc-AV crossing distance (DAVD)] in patients with BRVO ( 84 ).…”