Determination of corneal biomechanical properties in vivo: a review

Corneal biomechanical properties are essential for the early detection of corneal ectatic disease such as keratoconus, as well as for predicting and evaluating the visual outcome in corneal refractive surgery, the risk for corneal ectasia and the response to corneal collagen cross-linking. Advances in measurement of corneal biomechanical properties have the potential to enhance early keratoconus diagnosis, enable personalised, procedure specific ectasia risk assessment and optimise cross-linking treatment for stopping progression of corneal ectatic disease. Current corneal imaging technology provides an accurate anatomical and topographical analysis of the cornea, which is the ‘gold standard’ for the diagnosis of corneal ectatic disease and the preoperative screening in refractive surgery. Until recently, evaluation of corneal biomechanics was feasible only in vitro, since the technology required for in vivoanalysis was not available. However, in the recent years, there have been developed methods that enable an accurate in vivoanalysis of corneal biomechanics, thereby introducing a new era in corneal diagnostics and corneal refractive surgery.