Objective. To prospectively evaluate the effect of intravitreal
bevacizumab on aqueous levels of
interleukin-6 (IL-6) and
vascular endothelial growth factor (
VEGF) in patients with exudative
age-related macular degeneration (AMD) and correlate clinical outcomes with
cytokine levels. Methods. 30 eyes of 30 patients with exudative AMD underwent
intravitreal injection of
bevacizumab three times at monthly intervals. The aqueous samples prior to the 1st injection (baseline) and 3rd injection were analyzed for
VEGF and
IL-6 levels. Subjects were subgrouped based upon change in the central subfield (CSF) macular thickness on SD-OCT at 8 weeks. Group 1 included patients (n = 14) with a decrease in CSF thickness greater than 10% from the baseline (improved group). Group 2 included patients (n = 16) who had a decrease in CSF thickness 10% or less (treatment-resistant). Results. In subgroup analysis, in both groups 1 and 2 patients, compared to aqueous
VEGF, aqueous
IL-6 levels showed a better correlation with CSF thickness on SD-OCT (r = 0.72 and 0.71, resp.). Conclusions. Aqueous
IL-6 may be an important marker of treatment response or resistance in
wet macular degeneration. Future therapeutic strategies may include targeted treatment against both
VEGF and
IL-6, in patients who do not respond to anti-
VEGF treatment alone.