The role of microRNAs in the pathophysiology of the aging eye

The human eye is a complex organ integral to visual perception, comprising multiple structures, including the retina, cornea, and lens. Vision loss affects over 2.2 billion individuals globally, with conditions, such as age-related macular degeneration, cataracts, glaucoma, and diabetic retinopathy, recognized as responsible for a majority of visual-impairing conditions. Recent research highlights the critical roles of microRNAs (miRNAs)-small non-coding RNAs involved in post-transcriptional gene regulation-in ocular physiology and pathophysiology. miRNAs regulate gene expression by binding to target mRNA, modulating multiple processes like cell growth, apoptosis, and differentiation. Dysregulation of miRNAs has been implicated in various age-related ocular disorders like retinopathy, glaucoma and age-related macular degeneration, thereby disrupting cellular homeostasis and promoting disease progression. Experimental evidence, primarily from murine models, reveals that miRNAs regulate photoreceptor differentiation, retinal development, and the survival of postmitotic retinal cells. Additionally, miRNA dysregulation offers potential diagnostic and therapeutic insights. This study explores the roles of miRNAs in ocular pathophysiology, emphasizing their involvement in the maintenance of retinal cell integrity and visual system homeostasis. Furthermore, the significance of miRNAs in the pathogenesis of various human ophthalmic diseases associated with advancing age is reviewed.