Circular and long non-coding RNAs and their role in ophthalmologic diseases

Long non-coding RNAs are 200 nucleotide long RNA molecules which lack or have limited protein-coding potential. They can regulate protein formation through several different mechanisms. Similarly, circular RNAs are reported to play a critical role in post-transcriptional gene regulation. Changes in the expression pattern of these molecules are established to underline various diseases, including cancer, cardiovascular, neurological and immunological disorders. Recent studies suggest that they are differentially expressed both in healthy ocular tissues as well as in eye pathologies, such as neovascularization, proliferative vitreoretinopathy, glaucoma, cataract, ocular malignancy or even strabismus. Aetiology of ocular diseases is multifactorial and combines genetic and environmental factors, including epigenetic and non-coding RNAs. In addition, disorders like diabetic retinopathy or age-related macular degeneration lack biomarkers for early detection as well as effective treatment methods that will allow controlling the disease progression at its early stages. The newly discovered non-coding RNAs seem to be the ideal candidate for novel molecular markers and therapeutic strategies. In this review, we summarize current knowledge about gene expression regulators - long non-coding and circular RNA molecules in eye diseases.