Stem Cells and the Ocular Lens: Implications for Cataract Research and Therapy

A transparent and pliable lens is critical for good quality vision, effective motor and social development, life-long education and employment, and high quality of life. As individuals live beyond the age of 40 they experience progressive lens hardening, called presbyopia, that results in impaired vision due to a reduced ability to accommodate (i.e. to change focus between near and far objects). Due to its age of onset most people, at least in the developed world, will live roughly half their lives dealing with the vision-impairing consequences of presbyopia. Additionally, tens of millions of people have low vision or blindness due to the formation of lenticular opacities, called cataracts, that reduce lens transparency. Due to population ageing, age-related cataracts are becoming an increasing problem worldwide. Thus presbyopia and age-related cataracts are causing, and will increasingly cause, large social and economic hardship across the globe. While decades of research have provided some understanding of the molecular mechanisms that underpin these blinding conditions, new research and clinical therapies are needed to better treat these extensive, costly and life-altering conditions. Advances in stem cell research and technology provide a real opportunity to identify and develop these much-needed new therapies.