Aqueous humor inflammatory cytokine levels and choroidal thickness in patients with macular edema associated with branch retinal vein occlusion.

Abstract

We aimed to investigate the association between subfoveal choroidal thickness (SCT) and the level of aqueous humor (AH) inflammatory cytokines in patients with macular edema (ME) associated with branch retinal vein occlusion (BRVO). Twenty-eight eyes of 28 BRVO ME patients who underwent intravitreal injection treatment (ranibizumab, bevacizumab, or dexamethasone implant) were prospectively recruited. The concentrations of vascular endothelial growth factor (VEGF)-A and inflammatory cytokines were measured from AH samples. We analyzed clinical factors associated with visual gain or the degree of central macular thickness (CMT) decrease and the association between SCT and inflammatory cytokine levels. On multiple linear regression analysis, the AH interleukin (IL)-8 level was significantly associated with visual gain and CMT reduction at 6months. Age, systemic hypertension, and AH monocyte chemo-attractant protein 1 level showed a significant association with baseline SCT, and VEGF-A showed a significant association with baseline SCT ratio (BRVO eye SCT/fellow eye SCT). Those with thick SCT showed a higher level of AH soluble VEGF receptors 2 and IL-8 and showed better visual gain and greater CMT reduction at 2 and 6months compared to the thin SCT group. The level of AH inflammatory cytokines was significantly associated with the ischemic status of the retina, treatment outcomes, and SCT in BRVO ME patients. Thick baseline SCT might be a predictive sign for better treatment outcomes in BRVO ME patients which are thought to be related to a higher level of intraocular inflammatory cytokines in these patients.