Correlation Between Intraocular Pressure And Myopia Diopter,Axial Length And Choroidal Thickness

Objective:Through the analysis of intraocular pressure,diopter,axial length and the choroidal thickness at nine sites in the posterior pole,exploring the effects of different intraocular pressure levels on myopic refraction,axial length and choroidal thickness in myopic children,as well as the correlation between intraocular pressure and the other three,and understanding differences in intraocular pressure and choroidal thickness between myopic and non-myopic children.Methods:A total of 95 children who visited the Children’s Eye Clinic of our hospital from April 2021 to February 2022 and volunteered to participate in this study were included in 190 eyes.Non-myopic patients with normal vision were included in the control group(49 eyes of 34 cases)and myopic patients in the experimental group(141 eyes of 80 cases)according to diopter.According to the corrected intraocular pressure value,the experimental group was divided into group A: 15 mm Hg ≤IOPCorrected ≤ 18 mm Hg(17 cases,21 eyes);group B: 18 mm Hg < IOPCorrected ≤ 21 mm Hg(51 cases,72 eyes);Group C: 21 mm Hg < IOPCorrected ≤ 25 mm Hg(31 cases,48 eyes).Collecting eye parameters,including spherical equivalent(SE),intraocular pressure(IOP),central corneal thickness(CCT),axial length(AL),and choroidal thickness(CT)at nine sites.The IOP was corrected with reference to the IOPCorrected= IOP+(544-CCT)/37.03 corrected intraocular pressure formula.SPSS 26.0 software was used to analyze all the data,and the measurement data were expressed as mean standard deviation(`x±s).The data were in line with normal distribution and the homogeneity of variance was compared by one-way an OVA,but not by non-parametric test.The comparison between groups was in accordance with normal distribution and homogeneity of variance was tested by multiple LSD test,but not by multiple original rank sum test.Correlation analysis was consistent with the normal distribution using Pearson correlation analysis,but inconsistent with Spearman correlation analysis.P < 0.05 was statistically significant,P < 0.01 was notably,statistically significant.Results:(1)The IOPCorrected in experimental and control group were 20.74±2.52,19.55±2.57(mm Hg),the difference was statistically significant(P=0.011).In experimental group,T3,T1,SFCT,N1,N3,S3,S1,I1,I3 were 251.79 ±55.96,239.16±58.14,230.24±58.34,197.91±57.51,128.62±48.58,239.50 ±61.41,246.68±152.16,227.66±55.31,208.23±53.16(um).In control group,T3,T1,SFCT,N1,N3,S3,S1,I1,I3 were 287.61±61.77,281.53±55.92,271.47±61.17,233.98±55.19,152.47±43.08,277.24±63.30,269.71±62.72,263.94±53.75,251.31±54.16(um),The choroidal thickness of each point in the experimental group was significantly thinner,and the difference was statistically significant(P < 0.01).(2)IOPCorrected of group A,B,C were 17.25±0.63,19.7±0.89 and 23.82±0.88(mm Hg),with statistically significant differences among groups(P < 0.01).(3)The absolute value of SE in group A,B and C were 2.13±1.26,2.50±1.66 and3.21±1.72(D).The absolute value of SE in group C was significantly higher than that in group A and B,with statistical significance(P < 0.05).The absolute value of SE in group B was slightly higher than that in group A,but the difference was not statistically significant(P > 0.05).(4)The AL in group A,B and C were 24.57±0.74,24.49±0.88 and 24.77±0.90(mm)respectively,with no statistical significance(P > 0.05).(5)Choroidal thickness:1 In group B,T1,SFCT,S3,I3 were 256.76±50.23,249.00±55.51,257.33±61.39 and 222.43±45.54(um).In group B,T1,SFCT,S3,I3 were 246.13±50.37,236.86±49.85,249.60±61.37 and 214.92±46.01(um).T1,SFCT,S3,I3 in group C were 221.02±67.94,212.10±67.19,216.56±55.72 and 191.98±62.52(um).The choroidal thickness at four sites in group C was significantly thinner than that in group A and B,and the difference was statistically significant(P< 0.05).The choroidal thickness at four sites in group B was thinner than that in group A,but the difference was not statistically significant(P> 0.05).2 In group A,T3,N1,N3,S1,I1 were 254.00±60.50,213.71±57.07,139.05±47.53,241.48±53.95,235.00±55.11(um);In group B,T3,N1,N3,S1,I1 were257.86±53.90,200.94±54.26,132.49±47.44,242.36±59.64,232.85±49.89(um);In group C,T3,N1,N3,S1,I1 were 241.73±56.73,186.46±61.29,118.25±49.86,219.81±59.01,216.67±62.22(um).The choroidal thickness in group C was significantly thinner than in group A and B,but it was not significant(P> 0.05),and the choroidal thickness in group B was slightly thinner than in group A,but not significant(P> 0.05).(6)Correlation analysis between IOPCorrected and the absolute value of SE,AL,CT in experimental group: IOPCorrected was positively correlated with the absolute value of SE(r=0.218,P<0.01);There was no significant correlation with AL,N1,N3,S3,(P > 0.05);Negatively correlated with T3,T1,SFCT,S3,S1,I1,I3(r=-0.177,-0.260,-0.240,-0.258,-0.168,-0.166,-0.237,P < 0.05).Conclusion:(1)Compared with non-myopic children,the IOP of myopic children was higher,and the CT within 3mm of macular fovea was significantly thinner;(2)Higher intraocular pressure in myopic children indicated higher degree of myopia,and there was a positive correlation between IOP and the absolute value of SE;(3)With the increase of IOP,the CT within 3 mm of macular fovea and its surrounding area became thinner to varying degrees,and the thinning was more obvious in T1,SFCT,S3 and I3;(4)The IOP of myopic children was negatively correlated with the CT within 3 mm of macular fovea,outside the nose,but not with the axial length.