Comparison of the cytokines levels in aqueous humor in vitrectomized eyes versus non-vitrectomized eyes with diabetic macular edema

Abstract

Abstract Background To compare concentrations of VEGF family growth factors, inflammation-related factors, and adhesion molecules in the aqueous humor of eyes with diabetic macular edema (DME), with and without prior vitrectomy Methods A total of 31 eyes were included, 11 with DME that had undergone vitrectomy, 9 with DME but without vitrectomy, and 11 from age-related cataract patients as controls. The concentrations of cytokines including TNF-α, IL-6, IL-8, IP-10,MCP-1, IFN-γ, MIP-1 α, MIP-1 β, PECAM-1, MIF, VCAM-1, ICAM-1, PIGF were quantified using Luminex Human Discovery Assay. The relationship between cytokine levels and central macular thickness was evaluated using OCT. Results (1) The concentrations of VEGF, PlGF, IP-10, MCP-1, MIP-1α, MIP-1β, MIF, IFN-γ, TNF-α, PECAM-1, ICAM-1, and VCAM-1 in the aqueous humor of diabetic macular edema (DME) patients with and without vitrectomy were similar. Vitrectomized DME eyes exhibited significantly higher levels of IL-6 and IL-8 compared to non-vitrectomized eyes (P < 0.05). (2) In vitrectomized group, after Benjamini-Hochberg correction, there was a significant positive correlation between the levels of VEGF and PlGF (rs = 0.855, P < 0.05), the levels of TNF-α and IFN-γ were also significantly positively correlated (rs = 0.858, P < 0.05). In non-vitrectomized group, significant positive correlations were found between VEGF and PlGF levels after correcting for multiple comparisons (rs = 0.9, P < 0.05). (3) In non-vitrectomized group, the concentrations of VEGF and PlGF in aqueous humor were significantly positively correlated with CMT (rs = 0.95, P < 0.05; rs = 0.9, P < 0.05, respectively). Conclusions The concentrations of IL-6 and IL-8 in the aqueous humor were significantly higher in DME patients who underwent vitrectomy compared to those without vitrectomy, while the levels of VEGF were similar between the two groups which indicating that inflammation after vitrectomy may be a key factor in the occurrence and development of DME.