Abstract:AIM: To study the characteristics of new corneal biomechanical parameters in different degrees of myopia and analyze the correlation of the new parameter stress-strain index(SSI).
METHODS: A cross-sectional study was conducted on 366 adult patients(718 eyes)with different degrees of myopia who received treatment at the First Affiliated Hospital of Dali University from October 2021 to November 2021, aged 18-50 years, and the spherical equivalent(SE)was -0.50～-16.75D. The axial length(AL)of the eye was measured by IOL master, and the new corneal biomechanical parameters, central corneal thickness(CCT)and intraocular pressure(IOP)were measured by corneal visualization Scheimpflug technology(Corvis ST). The subjects were categorized into low myopia, moderate myopia and high myopia groups according to SE. The data were analyzed by ANOVA and Pearson correlation.
RESULTS: The ratio of the thinnest corneal thickness to horizontal thickness change rate(ARTh)and SSI were statistically significant(P<0.001), while the remaining parameters were not statistically significant(P>0.05). SSI was positively correlated with age(r=0.102, P=0.006), SE(r=0.361, P<0.001), IOP(r=0.175, P<0.001), CCT(r=0.098, P=0.009), SPA1(r=0.182, P<0.001), negatively correlated with AL(r=-0.331, P<0.001), IR(r=-0.545, P<0.001)and had no correlation with other corneal biomechanical parameters(P>0.05).
CONCLUSION: With the increase of myopia degree and the elongation of the axial length, the SSI value becomes smaller and the corneal hardness decreases. SSI may be a helpful corneal biomechanical indicator for future research on myopia.
