Characterization of Corneal Indentation Hysteresis

Abstract

The aim of this study is to design and develop a noninvasive corneal indentation method to measure the corneal hysteresis behavior under dynamic corneal indentation. Corneal indentation method is adapted for the design and development of a measurement method for the characterization of Corneal Indentation Hysteresis (CIH). Fourteen porcine eyes were tested using the corneal indentation method. The CIH measured in enucleated porcine eyes showed indentation rate and intraocular pressure dependences. The CIH increased with the indentation rate at lower IOP (< 25 mmHg) and the CIH decreased with the indentation rate at higher IOP (> 25 mmHg). The CIH was linear proportional to the IOP within an individual eye. The CIH was positively correlated with the IOP, corneal in-plane tensile stress and corneal tangent modulus (E). A new method based on corneal indentation for the measurement of Corneal Indentation Hysteresis in vivo is developed. To our knowledge, this is the first study to introduce the corneal indentation hysteresis and correlate the corneal indentation hysteresis and the corneal tangent modulus