Abstract
Purpose: :
There is an increasing emphasis on inflammatory processes in the aetiology of diabetic retinopathy (DR). Eales’ Disease (ED) is an overt inflammatory eye disease that can result in pre-retinal neovascuarisation, however, the connection between this disease and the proliferative stage of DR (PDR) remains uncertain. In patients with PDR or ED, this study has compared pro-inflammatory cytokines occurring in vitreous from both groups and explored the role that they play in angiogenesis ex vivo.
Methods: :
PDR (n=9), ED (n=5) vitreous samples were quantified for various cytokines by Cytokine Biochip Array (Randox, UK) and ELISA. Vitreous from patients with Macular Hole (MH) was used as a control (n=5). Tubulogenesis assay was performed using Human Dermal Microvascular Endothelial cells (HDMECs) and tube length was quantified using Nikon-NIS-Elements software
Results: :
PDR and ED vitreous had elevated levels of many cytokines, but especially IL6, MCP-1 and VEGF. PDR and ED vitreous showed greater ability to induce tube formation compared with the untreated controls (p<0.05; p<0.01) and there was a significant correlation between angiogenic capacity and the quantified levels of cytokines. Angiogenic capacity of vitreous samples, when mixed with Lucentis (0.5mg/ml) and/or anti-IL6 (0.1ug/ml) were neutralized, (mean fold decrease ranging from 0.2 to 1.2).
Conclusions: :
In addition to VEGF, inflammatory cytokines (IL6 and MCP-1) also play a central role in inducing retinal neovascularization in PDR and ED. The present result also indicates the possibility of interaction between cytokines and vascular growth factor.
Keywords: cytokines/chemokines • diabetic retinopathy • vitreous