Keratoconus

Keratoconus is classically considered a bilateral, asymmetric, noninflammatory corneal ectasia that is characterised by progressive thinning and steepening of the central cornea. These pathological changes lead to a relative reduction in vision, primarily as a result of the induction of irregular astigmatism. Contact lenses are the mainstay of vision correction for people with keratoconus. This chapter provides a comprehensive overview of the range of contemporary contact lens modalities, including soft, rigid (i.e. corneal, corneo-scleral and scleral lenses), hybrid and piggyback designs, that are available for the optical management of keratoconus. The application of anterior segment imaging technologies, including corneal topography and optical coherence tomography, to assist with contact lens fitting is also considered. Furthermore, the importance of monitoring for disease progression in people with keratoconus, particularly children, in the context of considering a patient’s potential suitability for corneal collagen cross-linking treatment, is discussed.