The Level of Cytokines in the Vitreous Body of Severe Proliferative Diabetic Retinopathy Patients Undergoing Posterior Vitrectomy

Objective: The objective of the study was to compare cytokine levels in the vitreous body of patients with proliferative diabetic retinopathy (PDR) undergoing posterior vitrectomy.

Patients and methods: The study included 39 patients (39 eyes) undergoing pars plana vitrectomy (PPV). Patients were divided into three groups: patients with proliferative diabetic retinopathy (PDR) without aflibercept injection prior to the surgery, PDR patients administered aflibercept injection prior to the surgery, and patients without diabetes mellitus (control group). All patients underwent a comprehensive eye examination one day before and 3 weeks after the surgery, including measurements of: best-corrected visual acuity (BVCA) and intraocular pressure (IOP), slit-lamp examination and spectral domain optical coherence tomography (SOCT). Concentrations of cytokines: IL-6, IL-8, IL-12p70, TNF, IL-10, IL-1β were measured in the vitreous body of patients with BD™ Cytometric Bead Array (CBA) Human Inflammatory Cytokines Kit.

Results: PDR patients who received pretreatment with aflibercept injection showed significantly lower concentrations of IL-12p70, TNF, IL-10 and IL-1β in the vitreous body compared to the control group. Meanwhile, patients without prior aflibercept injection had a significantly higher concentration of IL-8. There was also a significant positive correlation between IOP before PPV and IL-8 concentration in both PDR patients' groups.

Conclusion: Findings of our study suggest an important role of IL-8 in the development of severe PDR. Aflibercept administration on the day before elective vitrectomy facilitated the surgery.