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Chen L, Huang Y, Zhang X, Shi Y, Gao Z, Sun B, Shen Y, Sun L, Cao Y, Zhang Q, Guo J, Li F, Chen W, Li X, Zhou X. Corneal Biomechanical Properties Demonstrate Anisotropy and Correlate With Axial Length in Myopic Eyes. Invest Ophthalmol Vis Sci 2023; 64:27. [PMID: 37477932 PMCID: PMC10365135 DOI: 10.1167/iovs.64.10.27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 06/12/2023] [Indexed: 07/22/2023] Open
Abstract
Purpose The purpose of this study was to investigate the ex vivo and in vivo biomechanical characteristic of cornea in myopic eyes. Methods Fifty-one corneal stromal lenticules were obtained from myopic eyes during the SMILE procedure and were tested by a biaxial tensile system within 24 hours postoperatively. The material properties of the lenticules were described using stress-strain curves and were compared among axial length (AL) <26 mm and AL ≥ 26 mm group. Pre-operative stress-strain index (SSI) parameters were used to evaluate the biomechanical properties of the cornea in vivo. Results Compared with AL < 26 mm, the tangent modulus significantly decreased in horizontal and vertical directions when AL ≥ 26 mm (P < 0.05); SSI also significantly decreased when AL ≥ 26 mm (P < 0.05). Anisotropic parameter is positively correlated with AL (r = 0.307, P < 0.05). Compared with AL < 26 mm, anisotropic parameter significantly increased when AL ≥ 26 mm (P < 0.05). SSI was negatively correlated with AL (r = -0.380, P < 0.05) in the AL < 26 mm group but not in the AL ≥ 26 mm group (P > 0.05). Compared with 26 mm ≤ AL < 27 mm group, the tangent modulus significantly decreased in the horizontal direction (P < 0.05) but not in the vertical direction when 27 mm ≤ AL < 28 mm (P > 0.05). Conclusions The biomechanical properties of cornea decreased with the increase of AL. Tangent modulus significantly decreased in the horizontal direction compared with vertical direction. AL should be taken into account during calculation of corneal biomechanical parameters in order to improve validity.
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Affiliation(s)
- Lingfeng Chen
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China
| | - Yangyi Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Xiaoyu Zhang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yike Shi
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China
| | - Zhipeng Gao
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China
| | - Bingqing Sun
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yang Shen
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Ling Sun
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yifan Cao
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China
| | - Qianqian Zhang
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China
- Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, China
- School of Automation and Software Engineering, Shanxi University, Taiyuan, Shanxi, China
| | - Jiqiang Guo
- Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, China
| | - Fen Li
- College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan, China
- Institute of Applied Mechanics, Taiyuan University of Technology, Taiyuan, China
| | - Weiyi Chen
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China
| | - Xiaona Li
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, China
| | - Xingtao Zhou
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
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Association of Iris Structural Measurements with Corneal Biomechanics in Myopic Eyes. DISEASE MARKERS 2022; 2021:2080962. [PMID: 35003388 PMCID: PMC8741339 DOI: 10.1155/2021/2080962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/07/2021] [Indexed: 11/25/2022]
Abstract
Purpose To evaluate the relationship between iris sectional parameters on swept-source optical coherence tomography (SS-OCT) with corneal biomechanics measured by Corneal Visualization Scheimpflug Technology (Corvis ST) in young adults with myopia. Methods 117 patients with myopia aged ≥18 years were recruited from the Eye Hospital of Wenzhou Medical University, who had complete SS-OCT and Corvis ST data. Only the left eye of each participant was selected for analysis. Iris sectional parameters included iris thickness at 750 μm from the scleral spur (IT750), iris sectional area (I-area), and iris curvature (I-curv) measured from four quadrants. Associations between the iris parameters and corneal biomechanics were analyzed using linear regression models. Results The mean age of the included young adults was 26.26 ± 6.62 years old with 44 males and 73 females. The iris parameters were different among the four quadrants. The nasal, temporal, and inferior quadrants of IT750, together with nasal and temporal quadrants of I-area, were correlated with corneal biomechanical parameters after being adjusted for age, gender, pupil diameter, and axial length. Thicker IT750 and larger I-area were related to a softer cornea. However, no association was found between I-curv and corneal biomechanics. Conclusions Iris sectional parameters measured from SS-OCT images were associated with corneal biomechanical properties in myopic eyes. Thicker IT750 and larger I-area indicate a softer cornea. IT750 and I-area may provide useful information on corneal biomechanical properties in myopic eyes.
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