Association of Aqueous Humor Cytokines With the Development of Retinal Ischemia and Recurrent Macular Edema in Retinal Vein Occlusion

Abstract

We evaluated the association of angiogenic and inflammatory cytokine levels in the aqueous humor with development of retinal ischemia and recurrent macular edema in retinal vein occlusion (RVO) patients. This was a retrospective cross-sectional study, and patients with RVO (n = 41) and age-matched control subjects (n = 25) were included. The concentrations of angiogenic and inflammatory cytokines, including VEGF, PDGF-AA, IL-1a, IL-6, IL-8, MCP-1, TNF-α, and IP-10, in the aqueous humor were measured before intravitreal injection of bevacizumab using suspension array technology. After retinal hemorrhage disappeared, fluorescein angiography (FA) images were obtained. Based on FA data, RVO patients were divided into a nonischemic group and an ischemic group. We investigated the presence of recurrent macular edema using optical coherent tomography (OCT) during the follow-up period. We compared the levels of cytokines between RVO patients and control subjects, between nonischemic and ischemic groups, and between patients with and without recurrent macular edema. The levels of VEGF, PDGF-AA, IL-1a, IL-6, IL-8, MCP-1, TNF-α, and IP-10 in the aqueous humor were higher in the RVO group than in the control group. The levels of IL-8, PDFGF-AA, TNF-α, and VEGF in the aqueous humor were significantly higher in the ischemic RVO group than in the nonischemic RVO group. We did not observe any association between cytokine levels and recurrent macular edema. Angiogenic and inflammatory cytokines were overexpressed in RVO patients. Additionally, increased levels of IL-8, PDFGF-AA, TNF-α, and VEGF in the aqueous humor at the onset of RVO were associated with the development of future retinal ischemia in RVO patients.