The Effect of Axial Length Elongation on Corneal Biomechanical Property

Guihua Liu; Hua Rong; Ping Zhang; Yu Xue; Bei Du; Biying Wang; Jiamei Hu; Zhi Chen; Ruihua Wei

doi:10.3389/fbioe.2021.777239

The Effect of Axial Length Elongation on Corneal Biomechanical Property

Front Bioeng Biotechnol. 2021 Dec 2:9:777239. doi: 10.3389/fbioe.2021.777239. eCollection 2021.

Authors

Guihua Liu¹, Hua Rong¹, Ping Zhang¹, Yu Xue^{2

3}, Bei Du¹, Biying Wang¹, Jiamei Hu¹, Zhi Chen^{2

3}, Ruihua Wei¹

Affiliations

¹ Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
² NHC Key Laboratory of Myopia, Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.
³ Key Laboratory of Myopia, Shanghai Research Center of Ophthalmology and Optometry, Chinese Academy of Medical Sciences, Shanghai, China.

Abstract

Background: To investigate the correlation between the corneal biomechanical parameter stress-strain index (SSI) and axial length (AL) in moderately elongated eye (MEE) and severely elongated eye (SEE). Methods: This study included 117 eyes from 117 participants. Among them, 59 (50.4%) had MEE (AL<26 mm) and 58 (49.6%) had SEE (AL≥26 mm). AL was measured using Lenstar LS-900, and central corneal thickness (CCT) and anterior chamber volume (ACV) were measured using Pentacam. SSI was measured via corneal visualisation Scheimpflug technology (Corvis ST). Kolmogorov-Smirnov test, Student's t-test, and Pearson and partial correlation analyses were used for statistical analyses. Results: The mean (±SD) SSI was 1.08 ± 0.15 in the MEE group and 0.92 ± 0.13 in the SEE group (p < 0.01). SSI was positively correlated with age (MEE: r = 0.326, p < 0.05; SEE: r = 0.298, p < 0.05) in both groups; it was negatively correlated with AL (r = -0.476, p < 0.001) in the MEE group but not in the SEE group (p > 0.05). CCT was negatively correlated with AL (r = -0.289, p < 0.05) and ACV positively correlated with AL (r = 0.444, p < 0.001) in the MEE group. Neither CCT nor ACV was correlated with AL (p > 0.05) in the SEE group. Conclusion: Corneal biomechanical parameter SSI, which represents the stiffness of corneal tissue, was lower in the SEE group than in the MEE group. When analyzed separately, SSI was negatively correlated with AL in the MEE group, but not in the SEE group, which may provide insight into different ocular growth patterns between lower myopia and higher myopia.

Keywords: CorVis ST; anterior segment; axial length; corneal biomechanics; myopia.