Andrew K C Lam1, Ying Hon1, Leo K K Leung2, David C C Lam2. 1. School of Optometry, The Hong Kong Polytechnic University, Hong Kong. 2. Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong.
Abstract
PURPOSE: The aim of the study was to evaluate the repeatability of a new device for measuring corneal biomechanics. METHODS: Twenty-nine normal subjects aged 20-28 years (23.4 ± 1.7 years) underwent measurements of corneal stiffness and tangent elastic modulus using a novel corneal indentation device. Corneal topography, axial biometry and Goldmann applanation tonometry were also performed during the visit. Subjects returned after about 1 week, at approximately the same time, and with the corneal biomechanics, corneal topography and Goldmann applanation tonometry measured again. Both the intrasession and intersession repeatability was assessed. RESULTS: Both the corneal stiffness and tangent elastic modulus demonstrated good intrasession repeatability (corneal stiffness: coefficient of variation = 7.32%, intraclass correlation coefficient = 0.75; tangent elastic modulus: coefficient of variation = 7.34%, intraclass correlation coefficient = 0.84). The mean modulus after normalised to normal intraocular pressure of 15.5 mmHg was 0.755 ± 0.159 MPa. There was no significant difference between the two visits (paired t-tests: p > 0.05). The repeatability [1.96 times the standard deviation (S.D.) of the intersession difference] of the corneal stiffness and the tangent elastic modulus was 0.0022 N mm(-1) and 0.197 MPa, respectively. CONCLUSION: The corneal indentation device has good intrasession and intersession repeatability. It has good potential to measure corneal biomechanics clinically, even at different corneal regions.
PURPOSE: The aim of the study was to evaluate the repeatability of a new device for measuring corneal biomechanics. METHODS: Twenty-nine normal subjects aged 20-28 years (23.4 ± 1.7 years) underwent measurements of corneal stiffness and tangent elastic modulus using a novel corneal indentation device. Corneal topography, axial biometry and Goldmann applanation tonometry were also performed during the visit. Subjects returned after about 1 week, at approximately the same time, and with the corneal biomechanics, corneal topography and Goldmann applanation tonometry measured again. Both the intrasession and intersession repeatability was assessed. RESULTS: Both the corneal stiffness and tangent elastic modulus demonstrated good intrasession repeatability (corneal stiffness: coefficient of variation = 7.32%, intraclass correlation coefficient = 0.75; tangent elastic modulus: coefficient of variation = 7.34%, intraclass correlation coefficient = 0.84). The mean modulus after normalised to normal intraocular pressure of 15.5 mmHg was 0.755 ± 0.159 MPa. There was no significant difference between the two visits (paired t-tests: p > 0.05). The repeatability [1.96 times the standard deviation (S.D.) of the intersession difference] of the corneal stiffness and the tangent elastic modulus was 0.0022 N mm(-1) and 0.197 MPa, respectively. CONCLUSION: The corneal indentation device has good intrasession and intersession repeatability. It has good potential to measure corneal biomechanics clinically, even at different corneal regions.
Authors: Arthur J Sit; Shuai-Chun Lin; Arash Kazemi; Jay W McLaren; Christopher M Pruet; Xiaoming Zhang Journal: J Glaucoma Date: 2017-11 Impact factor: 2.503
Authors: Byung Soo Kang; Li-Ke Wang; Yong-Ping Zheng; Jeremy A Guggenheim; William K Stell; Chea-Su Kee Journal: PLoS One Date: 2018-11-12 Impact factor: 3.240