Estimation of the Corneal Young's Modulus In Vivo Based on a Fluid-Filled Spherical-Shell Model with Scheimpflug Imaging

Po-Jen Shih; Chun-Ju Huang; Tzu-Han Huang; Hung-Chou Lin; Jia-Yush Yen; I-Jong Wang; Hui-Jyun Cao; Wen-Pin Shih; Chi-An Dai

doi:10.1155/2017/5410143

Estimation of the Corneal Young's Modulus In Vivo Based on a Fluid-Filled Spherical-Shell Model with Scheimpflug Imaging

J Ophthalmol. 2017:2017:5410143. doi: 10.1155/2017/5410143. Epub 2017 Nov 8.

Authors

Po-Jen Shih¹, Chun-Ju Huang², Tzu-Han Huang², Hung-Chou Lin³, Jia-Yush Yen², I-Jong Wang⁴, Hui-Jyun Cao², Wen-Pin Shih², Chi-An Dai⁵

Affiliations

¹ Department of Civil and Environmental Engineering, National University of Kaohsiung, Kaohsiung, Taiwan.
² Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan.
³ Dr. Lin's Eye Clinic and Laser Vision Correction Center, Taoyuan City, Taiwan.
⁴ Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan.
⁵ Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan.

Abstract

Current intraocular pressure (IOP) measurement using air puff could be erroneous without applying proper corrections. Although noncontact tonometry is not considered to be accurate, it is still popularly used by eye clinics. It is thus necessary to extract the correct information from their results. This study proposes a practical approach to correctly measure IOP in vivo. By embedding a new model-based correction to the Corvis® ST, we can extract the corneal Young's modulus from the patient data. This Young's modulus can be used to correct the IOP readings. The tests were applied to 536 right eyes of 536 healthy subjects (228 male and 308 female) between March of 2012 and April of 2016. The tests were applied to patients at the Department of Ophthalmology, National Taiwan University Hospital and the Hung-Chuo Eye Clinics. The statistical analysis showed that the value for the Young's modulus was independent of all the other parameters collected from the Corvis ST, including the corneal thickness and the intraocular pressure. Therefore, it is important to independently measure the Young's modulus instead of depending on the correlation with the other parameters. This study adds the methodology of measuring corneal stiffness in vivo for ophthalmologists' reference in diagnosis.