Relationship between distribution and severity of non-perfusion and cytokine levels and macular thickness in branch retinal vein occlusion

Abstract

We aimed to investigate the relationship between non-perfusion on ultra-widefield angiography (UWF FA) and aqueous cytokine levels and central macular thickness (CMT) in eyes with branch retinal vein occlusion (BRVO). Thirty-five eyes with treatment-naïve BRVO were included. Non-perfusion area (NPA) for partial and complete ischemia was manually segmented and the ischemic index (ISI) for each was calculated using stereographically projected UWF FA for four different retinal zones. Partial and complete ischemia had different regional predominance. Partial ischemia was predominant in the posterior regions, while complete ischemia was predominant in the periphery. And partial ischemic area, located posterior to far periphery, showed significant correlation with central macular thickness and concentrations of angiogenic and inflammatory cytokines, while complete ischemic area showed no correlation with any of the parameters. Taken together, partial but not complete ischemia, particularly in the more posterior retina, was associated with higher cytokine levels and more severe macular edema in eyes with BRVO. These findings would help us to better understand the different clinical significance of ischemia in BRVO depending on the severity and regional distribution.

Analysis of the Cytokine Expression in the Aqueous Humor of Individuals with BRVO-Associated Macular Edema

“…Based on the data obtained ( P > 0.05), no significant association was identified between BCVA and the degree of ME in patients. However, Ryu et al [ 26 ] demonstrated a strong correlation between baseline BCVA and CMT, in contrast to our findings. The finding of our study indicates that the degree of BCVA and ME are not significantly associated, which is similar to the findings of Fujino et al [ 27 ].…”

“…This could be because the level of cytokines expressed in aqueous humor does not correctly reflect the real state of the retina, as the level of cytokines expressed in the aqueous humor is modified by their diffusion rate and interaction with the extracellular matrix. The damage of cytokines and their cascades to photoreceptors and neurons in the inner layer of the retina cannot be synchronized [ 26 ]. Therefore, there is no apparent correlation between BCVA and the expression levels of VEGF, IL-6, ICAM-1, and VCAM-1 in the aqueous humor.…”

“…e damage of cytokines and their cascades to photoreceptors and neurons in the inner layer of the retina cannot be synchronized [26]. erefore, there is no apparent correlation between BCVA and the expression levels of VEGF, IL-6, ICAM-1, and VCAM-1 in the aqueous humor.…”

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

“…In the retina, IL-6 is related to ischemia and vessel injury. In BRVO, IL-6 is significantly related to NPA ( 166 ) and caused macular edema secondary to BRVO ( 146 ). During inflammation, IL-6 binds with IL-6R forming a compound which then combines with gp130 and activates the downstream STAT3 and JAK-MAPK pathways.…”

Deep Capillary Plexus as Biomarker of Peripheral Capillary Nonperfusion in Central Retinal Vein Occlusion

“… 16 Moreover, the regions of peripheral CNP detected on UWFFA were further subclassified as partial CNP, complete CNP, and total CNP. 17 Partial CNP was characterized by the presence of a cluster of small fragmented areas of hypofluorescence, with dilation and irregular patterns in the capillary network; complete CNP was defined as a contiguous area of hypofluorescence due to retinal capillary loss and the obstruction of the precapillary arterioles and postcapillary venules, with the remaining precapillary arterioles and postcapillary venules being dilated and tortuous. 17 Total CNP was the sum of the 2 previous categories.…”