Circulating MicroRNAs as Biomarker for Vessel-Associated Retinal Diseases

Vessel-associated retinal diseases are a major cause of blindness and severe visual impairment. The identification of appropriate biomarkers is of great importance to better anticipate disease progression and establish more targeted treatment options. MicroRNAs (miRNAs) are short, single-stranded, non-coding ribonucleic acids that are involved in the post-transcriptional regulation of gene expression through hybridization with messenger RNA. The expression of certain miRNAs can be different in patients with pathological processes and can be used for the detection and differentiation of various diseases. In this study, we investigate to what extent previously in vitro identified miRNAs are present as cell-free circulating miRNAs in serum and vitreous of human patients with and without vessel-associated retinal diseases.Relative quantification by qRT-PCR was used to analyze miRNA expression in patients with vessel-associated retinal diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR) and retinal vein occlusion (RVO) compared with control patients.In serum samples, miR-29a-3p and miR-192-5p showed increased expression in patients with neovascular AMD relative to control patients. Similarly, miR-335-5p, miR-192-5p, and miR-194-5p showed increased expression in serum from patients with proliferative DR. In vitreous samples, miR-100-5p was decreased in patients with proliferative DR. Differentially expressed miRNAs showed good diagnostic accuracy in Receiver Operating Characteristic (ROC) and Area under the ROC Curve (AUC) analysis.The miRNAs investigated in this study may have the potential to serve as biomarkers for vessel-associated retinal diseases. Combining multiple miRNAs may enhance the predictive power of the analysis.