Purpose
To investigate the influence of intravitreal dexamethasone implant on inflammatory and angiogenic cytokine levels in the aqueous of patients with retinal vein occlusion (RVO).
Methods
Forty eyes of 40 consecutive patients with macular oedema (ME) due to branch and central retinal vein occlusion (BRVO/CRVO) were treated with an intravitreal dexamethasone implant (Ozurdex®) at baseline and evaluated until month 6. Retreatment was performed in case of recurrent ME earliest 4 months after the baseline treatment. Aqueous humour samples were taken at baseline, months 1, 3, 6 and at the time of each retreatment. Concentrations of 29 different cytokines were measured by Luminex® bead assays. The control group comprised healthy patients undergoing cataract surgery.
Results
At baseline concentrations of interleukin (IL)‐8, angiopoietin (ANG)‐2 and intercellular adhesion molecule (ICAM)‐1 were highly elevated in patients with CRVO compared with controls (p = 0.006; p = 0.02; p = 0.03). Vascular endothelial growth factor (VEGF) concentrations were upregulated in patients with BRVO and CRVO (p = 0.003; p = 0.001). Retreatment with a dexamethasone implant was necessary after 4 months in 14/8 (BRVO/CRVO) patients, 5 months in 5/3 patients and 6 months in one patient (BRVO). After the initial treatment, macrophage chemo‐attractant protein (MCP)‐1 and IL17‐E concentrations decreased in BRVO (p < 0.001; p = 0.01) and MCP‐1 and IL1‐α in CRVO (p = 0.01; p = 0.003). Vascular endothelial growth factor (VEGF) concentrations did not change during treatment in either group (p = 0.3). A mixed‐effect model showed that cytokine concentrations positively correlated with central retinal thickness changes.
Conclusions
Intravitreal dexamethasone treatment resulted in alterations in the concentrations of pro‐inflammatory cytokines MCP‐1 and IL17‐E in patients with BRVO and MCP‐1 and IL1‐α in patients with CRVO. These data highlight the important role of inflammatory mediators involved in ME due to RVO.