The ageing ocular surface:challenges for biomaterials design and function

Changing demographics and in particular an increasingly ageing population, in combination with improved longevity, will have a major impact on changing the face of human diseases and likewise the demand for appropriate biomaterials. The ocular surface is a multifaceted system that combines to create a unique mucosal surface, which includes the cornea, conjunctiva, sclera and lids of the eye. Physical parameters such as the eyelids and eyelashes, combined with the numerous secretory glands that produce the complex tear film, act together to protect and maintain the cornea. Unfortunately an ageing tear film and lacrimal functional unit can lead to impairment of this magnificently orchestrated structure. No single mechanism or modification is responsible but, whatever the cause, the consequence is a reduction in tear stability. An uncompromised tear film is fundamental to a healthy ocular surface. In the face of progressively changing demographics and consequent requirements for medical intervention and medical device developments, it is important to understand what effects the ageing process has on these anterior ocular structures.