Micro-RNAs and their roles in eye disorders.

Micro-RNAs (miRNAs) are members of the family of noncoding RNA molecules that regulate gene expression by translational repression and mRNA degradation. Initial identification of miRNAs revealed them only as developmental regulators; later, their radiated roles in various cellular processes have been established. They regulate several pathways, including developmental timing, hematopoiesis, organogenesis, apoptosis, cell differentiation and proliferation. Their roles in eye disorders are being explored by biologists around the world. Eye physiology requires the perfect orchestration of all the regulatory networks; any defect in any of the networks leads to eye disorders. The dysregulation of miRNA expression has been reported in many eye disorders, which paves the way for new therapeutics. This review summarizes the biogenesis of miRNAs and their role in eye disorders. miRNA studies also have implications for the understanding of various complex metabolic pathways leading to disorders of the eye. The ultimate understanding leads to potential opportunities in evaluating miRNAs as molecular biomarkers, prognostic tools, diagnostic tools and therapeutic agents for eye disorders.