Correlation Analysis Of Anterior Segment Biometric Values In High Myopia

Objective: The choice of phakic intraocular lens model is very clinically important.This article aims to explore the correlation among the biometric values related to lens selection in the anterior segment of high myopia at different anterior chamber depths,that is,the horizontal corneal diameter,anterior chamber angle diameter and ciliary sulcus diameter,to analyze whether it is possible to determine the type of intraocular lens with external measurement.Methods: A total of 73 eyes of 39 patients with high myopia who underwent the preoperative examination in the Ophthalmology Department of the second Hospital of Anhui Medical University from July 2017 to December 2017 were collected.The horizontal corneal diameter(White-to-White,WTW)and the depth of anterior chamber(Anterior Chamber Depth,ACD)were measured by Pentacam,and the horizontal diameter of anterior chamber angle(Angle-to-Angle,ATA)was measured by anterior segment coherence tomography(AS-OCT).The horizontal diameter of ciliary sulcus(Sulcus-to-Sulcus,STS)was measured by ultrasound biomicroscopy(Compact Touch STS UBM).According to the ACD,all the eyes were divided into three groups: shallow anterior chamber(2.8 mm ≤ ACD < 3.2 mm)(30 eyes),median anterior chamber(3.2 mm ≤ ACD ≤ 3.4 mm)(20 eyes),and deep anterior chamber(ACD > 3.4 mm)(23 eyes).Pearson linear correlation analysis and linear regression equation analysis were performed among WTW,ATA and STS in the three groups.WTW,ATA and STS among the three groups were analyzed by one-way ANOVA and SNK test.Results: In the shallow anterior chamber group,there was a significant linear correlation between WTW and ATA(p<0.001,r=0.759).There was a significant linear correlation between ATA and STS(p=0.002,r=0.538),a weak correlation between WTW and STS(p=0.041,r=0.375).In the middle anterior chamber group,in the correlation analysis,the correlation analysis between WTW and ATA was statistically significant(p=0.001,r=0.667),the difference between WTW and STS and between WTW and ATA were not statistically significant.There was a significant linear correlation between WTW and ATA in the deep anterior chamber group(p<0.001,r=0.839).There was a significant linear correlation between ATA and STS(p=0.001,r=0.638),and a weak correlation between WTW and STS(p=0.018,r=0.488).WTW,ATA and STS were homogeneity of variance among the three groups(p=0.177,0.059 and 0.563,respectively).In one-way ANOVA,there was no significant difference in WTW among the three groups(F=1.911,p=0.156),but there was significant difference in ATA among the three groups(F=4.910,p=0.010),and there was significant difference in STS among the three groups in oneway ANOVA(F=7.157,p=0.001).In SNK test,there was no significant difference in WTW among the three groups.There was significant difference in ATA between shallow anterior chamber and middle anterior chamber and deep anterior chamber,but there was no significant difference between middle anterior chamber and deep anterior chamber.There were significant differences in STS between shallow anterior chamber and middle anterior chamber and deep anterior chamber among the three groups,but there was no significant difference between middle anterior chamber and deep anterior chamber.Conclusion:1.Through Pearson linear correlation analysis and linear regression equation analysis among WTW,ATA and STS under different anterior chamber depth,the results show that it is not accurate to use external measurement data to predict the internal anatomical data of the eye to select the crystal mode,which will increases the incidence of complications due to the unsuitable intraocular lens model.It is safer to measure intraocular structural parameters directly by using intraocular data measuring instruments such as UBM and AS-OCT.2.One-way ANOVA and SNK test were used to analyze the pairwise differences of WTW,ATA and STS among the three groups.It was found that there was no significant difference in horizontal WTW under different anterior chamber depth,but ATA and STS increased gradually with the increase of anterior chamber depth.