Objective and subjective performance of scleral lenses and new advances in scleral lens technologies

Scleral lenses are widely recognized for their ability to markedly improve quality of life and giving back patients their ability to perform daily activities, mainly as a result of restoring visual function and/or reduction of ocular discomfort and pain.Scleral lenses are an important front-line tool for managing many corneal disorders refractory to other treatment measures and that otherwise would require keratoplasty. These disorders include conditions in which the cornea requires suitable optical correction in irregular surface, as well as to relieve symptoms, provide mechanical correction and/or facilitate corneal healing in ocular surface disease. The fundaments for the research projects in this thesis started with the development of two key innovations (back-surface toric and tangential design) in scleral lenses by our team. These innovations are important steps towards maximizing patient comfort and optimizing scleral lens performance. The clinical and patient-oriented benefits of these internationally renowned breakthroughs are discussed in this thesis. This thesis starts with a general introduction of the fundamental properties, complications, and indications of scleral lenses. Subsequently the role of scleral lenses in the context of other contact lens types is examined and made accessible for practitioners, by supplying a lens selection algorithm. Furthermore the focus of the research is on the indications and performance of modern scleral lenses, including the recent advances in scleral lens technologies (i.e., back-surface toric and tangential scleral lenses). Lastly, the use of scleral lenses following a relatively new treatment option for keratoconus (corneal crosslinking, or CXL) is evaluated, and the effect of scleral lens use on corneal physiology is examined.