Local Inflammatory Biomarkers and Potential Inflammation-Targeting Therapies in Diabetic Retinopathy

Abstract

Diabetic retinopathy (DR) is one of the most frequent microvascular complications of diabetes. A large body of evidence supports the role of inflammation in the development and progression of DR. Currently, DR is diagnosed based on the presence of morphological lesions detected on fundus examination. Yet, there are other laboratory or imaging biomarker whose alteration precede DR lesions. This chapter will first briefly explain the role of inflammation in DR pathogenesis and will analyze the molecules involved. Further, it will discuss significant and recent studies that analyzed local laboratory or imaging inflammatory biomarkers in different DR stages. It will then focus on several potential inflammation-targeting therapies which proved to be effective in animal or human studies. Validation of these reviewed biomarkers would allow the identification of patients who do not respond to the current available treatment and could benefit from an adjunctive therapy.

Aqueous Humor Cytokines in Non-Proliferative Diabetic Retinopathy

“…IL-6 is a potent pro-inflammatory cytokine up-regulated early in inflammation [ 19 ], and it is involved in inflammation and angiogenesis by VEGF induction [ 5 ]. IL-6 and VEGF AH concentrations are correlated [ 25 ].…”

“…Cytokines are small cell-signaling proteins whose identification may serve as inflammatory biomarkers or early indicators of progressive disease [ 2 , 3 ]. Cytokines can be harvested from serum, tears, aqueous humor (AH) or vitreous humor (VH) [ 4 , 5 ]. It has been shown that concentrations from AH and VH are comparable [ 6 , 7 ], while the serum quantifications might not directly reflect the intraocular changes.…”