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Updated: May 3, 2026

Characterization of a Novel Human Organotypic Retinal Culture Technique
Published on: June 9, 2021
Increased intravitreous interleukin-18 correlated to vascular endothelial growth factor in patients with active
Zongming Song1, Min Sun, Fen Zhou
1Eye Hospital, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, China, 325027.
Purpose:
To determine the intravitreous levels of interleukin-18 (IL-18) and vascular endothelial growth factor (VEGF) in patients with proliferative diabetic retinopathy (PDR) and to ascertain their association with PDR activity.
Methods:
Thirty eyes of 30 diabetic patients with PDR were divided into two groups (active PDR, n = 17; quiescent PDR, n = 13). Fifteen eyes of 15 non-diabetic patients (macular hole, n = 9; epiretinal membrane, n = 6) served as controls. All vitreous fluid samples were obtained during vitrectomy. IL-18 and VEGF were measured by enzyme-linked immunosorbent assay. Serum glycosylated hemoglobin as well as the basic demographic data was documented.
Results:
Both IL-18 and VEGF levels were higher in patients with PDR than control (P < 0 .01 and P < 0 .01, respectively). Both IL-18 and VEGF in active PDR were higher than those in quiescent PDR (P = 0.048 and P = 0.03, respectively). A significant positive correlation (Spearman rank correlation coefficient (r s) = 0.502, P = 0.005) between IL-18 and VEGF was observed in all PDR patients but not in the control. The correlation between VEGF and IL-18 was even stronger in the subgroup of active PDR (r s = 0.684; P = 0.002), whereas no significant correlation was found in the subgroup of quiescent PDR (r s = 0.049; P = 0.873).
Conclusions:
Both intravitreous IL-18 and VEGF were elevated in patients with PDR, which were closely correlated in active PDR. IL-18 may contribute to retinal angiogenesis by acting together with or via VEGF, and become the potential therapeutic target for treatment of PDR.

