角膜生物力学及校正眼压与青少年屈光状态的相关性

The Relationship between Corneal Biomechanics,Biomechanically Corrected Intraocular Pressure and Refractive Status in Chinese Juveniles

目的:探讨7~18岁青少年角膜生物力学及校正眼压与屈光状态的内在关系。方法:横断面研究。选择2017年11月至2018年2月于中山大学中山眼科中心屈光门诊就诊的中国青少年325例,年龄7~18岁,等效球镜度(SE)-10.25^+16.50 D。采用IOLMaster测量眼轴长度(AL),Corvis ST测量角膜生物力学参数及生物力学校正眼压(bIOP),Pentacam测量眼前节生物学参数。按照右眼SE将受检者分为高度近视、中低度近视、正视和远视组。采用Pearson或Spearman相关分析SE与角膜生物力学参数的相关性。用协方差分析比较4组的角膜生物力学参数差异,用方差分析比较4组间的bIOP差异。结果:SE越偏向近视,第二次压平速率(VA2,r=0.180,P=0.001)越快,峰值距离(PD,r=-0.273,P<0.001)和形变幅度(DA,r=-0.167,P=0.002)越大。AL越长,PD(r=0.355,P<0.001)越大,VA2(r=-0.138,P=0.021)越快。4组间PD(F=9.372,P<0.001)、DA(F=4.425,P=0.005)和VA2(F=4.961,P=0.002)的总体差异有统计学意义,进一步比较发现,PD、DA和VA2绝对值在高度近视、中低度近视、正视、远视组间依次下降,差异均有统计学意义(均P<0.05)。高度近视组(102.04±19.59)和中低度近视组(98.95±16.62)的角膜硬度参数(SP-A1)差异无统计学意义,但中低度近视组比正视组(107.49±18.66,P=0.010)和远视组(108.98±20.20,P=0.004)的SP-A1低,差异有统计学意义。眼压(IOP)和bIOP均与SE无相关性。结论:7~18岁青少年SE越偏向近视,角膜硬度越低。无论是否校正角膜生物力学因素的影响,眼压均与屈光度无关。

Objective:To explore the relationship between corneal biomechanics,biomechanically corrected intraocular pressure(bIOP)and refractive status in Chinese juveniles.Methods:This was a cross-sectional study conducted at the Zhongshan Ophthalmic Center between November 2017 and February 2018.A total of 325 Chinese juveniles,aged 7 to 18 years with a spherical equivalent(SE)refraction between-10.25 and+16.50 diopters(D)were included.Axial length(AL)was measured using an IOLMaster.Corneal biomechanical metrics and bIOP were measured using a Corvis ST,and corneal biological parameters were measured using a Pentacam.Participants were divided into 4 groups:high myopia,low-to-moderate myopia,emmetropia,and hyperopia based on the right eye SE.Differences in corneal biomechanical characteristics among the 4 groups were analyzed by covariance analysis,while differences in bIOP were analyzed by ANOVA.Results:Higher myopic SE was significantly correlated with faster corneal velocity during the second applanation moment(VA2,r=0.180,P=0.001),the longer peak distance(PD,r=-0.273,P<0.001)and larger deformation amplitude(DA,r=-0.167,P=0.002).A longer AL was significantly correlated with a faster VA2(r=-0.138,P=0.021)and longer PD(r=0.355,P<0.001).There were significant differences among the 4 groups in PD(F=9.372,P<0.001),DA(F=4.425,P=0.005),and VA2(F=4.961,P=0.002).Further study found that the PD,DA and absolute value of VA2 successively decreased in high myopia,low-to-moderate myopia,emmetropia,and hyperopia groups(all P<0.05).The differences in the stiffness parameter at the first applanation(SP-A1)in high myopia(102.04±19.59)and low-to-moderate myopia groups(98.95±16.62)were not significant(P>0.05),while the SP-A1 of the low-to-moderate myopia group was significantly greater than that of the emmetropia(107.49±18.66,P=0.010)and hyperopia groups(108.98±20.20,P=0.004).There was no significant correlation between intraocular pressure(IOP)/bIOP and SE.Conclusions:Corneal stiffness seems to decrease with a higher myopic SE in Chinese juveniles aged 7 to 18 years.IOP,whether it was corrected by corneal biomechanics or not,is not related to refractive status.