Effect of intravitreal dexamethasone implant on intraocular cytokines and chemokines in eyes with branch and central retinal vein occlusion

Abstract

Purpose : To investigate the influence of intravitreal dexamethasone implant on inflammatory and angiogenic cytokine levels in the aqueous of patients with branch and central retinal vein occlusion (BRVO/ CRVO).

Methods : In this prospective clinical trial, 40 eyes of 40 consecutive patients with macular edema (ME) due to BRVO/CRVO (25/15 patients) were treated with dexamethasone intravitreal implant (Ozurdex®) at baseline and evaluated until month 6. After 4 months re-treatment was allowed in case of recurrent ME. Aqueous humor samples were taken at baseline, month 1, month 3, month 6 and at each time of re-treatment. Concentrations of 29 different inflammatory and angiogenic cytokines were measured in the aqueous of BRVO/CRVO patients by Luminex® bead assays. A control group consisting of patients undergoing cataract surgery was included.

Results : At baseline levels of interleukin (IL)-8, angiopoietin (ANG)-2 and intercellular adhesion molecule (ICAM)-1 were highly elevated in patients with CRVO compared to healthy controls (p=0.002; p=0.007; p=0.001). VEGF levels were significantly upregulated in both BRVO and CRVO patients (p=0.003; p=0.001). Re-treatment with dexamethasone implant was necessary after 4 months in 14/8 (BRVO/CRVO) patients, in 5/3 after 5 months and in 1 patient (BRVO) after 6 months due to recurrence of ME. Significant reduction of macrophage chemoattractant protein (MCP)-1 and IL17-E in BRVO (p<0.001; p=0.01) and MCP-1 and IL1-α concentrations in CRVO (p=0.01; p=0.003) occurred after initial dexamethasone treatment. VEGF levels did not significantly change during treatment in either group (p=0.3). A mixed effect model showed cytokine levels to be positively correlated with central retinal thickness changes.

Conclusions : Several inflammatory cytokines were correlated with disease activity in BRVO and CRVO patients. Intravitreal dexamethasone treatment resulted in significant alterations of the pro-inflammatory cytokines MCP-1 and IL17-E in patients with BRVO and MCP-1 and IL1-α in patients with CRVO.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.