Epigenetics in Ocular Medicine

Many eye diseases have complex etiologies. Though numerous risk alleles and biological pathways have been implicated in the development of such diseases, they cannot be fully explained by known genetic factors. It is now known that epigenetic factors contribute to the development and progression of many eye diseases. These epigenetic modifications are dynamic, work via diverse mechanisms, and some components of our epigenome can be affected by the environments we have been exposed to during our lifetime. Epigenetic modifications can be used medically as biomarkers for predicting disease status or progression, and some may be potential targets for future therapeutic strategies. The epigenetic mechanisms implicated in ocular disease include DNA methylation, histone modification, and microRNA regulation. In this chapter we will describe how epigenetic modifiers affect key elements of ocular disease, such as cell proliferation, oxidative stress, angiogenesis, and inflammation. We have grouped ocular diseases into three general areas for discussion: proliferative (including cancer), complex, and age-related disease. The impact of the epigenome on inherited retinal diseases will also be briefly discussed.