The Decentration And Tilt Related Studies Of Crystalline Lens And Intraocular Lens Using New Swept-Source Ocular Coherence Tomography

Part Ⅰ Repeatability of Swept-Source Ocular Coherence Tomography CASIA2 Measurement of Decentration and Tilt of Crystalline Lens and Intraocular Lens in Cataract PatientsObjective:To evaluate the repeatability of measurement of decentration and tilt of crystalline lens and intraocular lens(IOL)in cataract patients by a new anterior segment OCT CASIA2.Methods:The diagnostic test was carried out in this study.109 cataract patients with 157 eyes(including 80 right eyes and 77 left eyes)received cataract surgery in the Affiliated Hospital of North Sichuan Medical College from March to July in 2020.CASIA2(Tomey,Japan)was used by the same examiner to measure the decentration and tilt of crystalline lens before and after pupil dilation for three consecutive times,and the decentration and tilt of IOL were measured again one week later after phacoemulsification combined with aspheric IOL(SN60WF,Alcon,USA)implantation.The device can obtain the measurement data directly.Within-standard deviation(Sw),test-retest repeatability(TRT),coefficient of variation(CoV)and intraclass correlation coefficient(ICC)were used to evaluate the repeatability of CASIA2 in measuring the decentration and tilt of crystalline lens and IOL in cataract patients.At the same time,Pearson correlation coefficient was used to test the correlation between decentration and tilt of lens and IOL before and after pupil dilation.Results:The repeatability of CASIA2 in measuring crystalline lens decentration of cataract patients before and after mydriasis was poor,in which the ICC values were 0.817 and 0.777 respectively,the TRT percentages were both more than 50%,and the CoV values were 23.023%and 25.100%respectively.The repeatability of measuring the decentration of IOL before and after mydriasis was good,in which the ICC values were 0.937 and 0.984 respectively,the TRT percentage were both less than 50%,and the CoV values were 14.840%and 7.331%respectively.Under the condition of non-mydriatic and mydriatic,the repeatability of measuring crystalline lens tilt is good,and the ICC values are both 0.815 and the percentages of TRT are less than 50%.The CoV are 13.029%and 12.054%respectively.The repeatability of measuring the decentration and tilt of IOL before and after mydriasis was good,the ICC values were both greater than 0.815,the percentages of TRT were both less than 50%,and the CoV values range from 12.054 to 13.721.The repeatability of CASIA2 in measuring the tilt of right and left eye lenses before and after mydriasis was good.ICC values range from 0.757 to 0.845,TRT percentages were both less than 50%,and CoV values range from 11.464%to 14.494%.By analyzing the right and left eye separately,it was found that the ICC range of measuring the crystalline lens decentration of the right eye and the left eye was 0.737 to 0.856,the percentage of TRT were both greater than 50%,and the CoV values were between 20.061%-26.824%,so the repeatability is poor.The repeatability of measuring the decentration,decentration axis,tilt and tilt axis of right-eye and left-eye IOLs was good,in which the ICC values ranged from 0.929 to 0.998,the percentage of TRT were both less than 50%,and the CoV values ranged from 0.977%to 17.763%.The repeatability of CASIA2 in measuring the decentralized axial and tilted axial of the crystalline lens in the right and left eyes was good,with the percentage of ICC values ranging from 0.917 to 0.997,TRT less than 50%and the CoV values ranging from 1.939%to 4.977%.At the same time,there was a good correlation between crystalline lens and IOL before and after pupil dilation(r≥0.678,P<0.01).Conclusion:The repeatability of CASIA2 in measuring the tilt of cataract patients before and after mydriasis was good,but the repeatability of measuring decentration was poor,and the repeatability of decentration and tilt of IOL was good.According to the separate analysis of the right eye and the left eye,except for the decentration,the CASIA2 measurement of the axis of decentration,tilt and the axis of tilt of cataract patients had good repeatability under non-mydriatic conditions and mydriatic conditions.The repeatability of decentration,the axis of decentration,tilt,and the axis of tilt of IOL measured by CASIA2 under non-mydriatic conditions and mydriatic conditions were both good.At the same time,there was a good correlation between crystalline lens and IOL measured by CASIA2 under non-mydriatic conditions and mydriatic conditions.Part Ⅱ Correlation of Decentration and Tilt of Crystalline Lens and Intraocular Lens Measured by SS-OCT CASIA2Objective:To explore the correlation between the pre-operative crystalline lens and the post-operative IOL position by using a new type of anterior segment OCT CASIA2 to measure the decentration and tilt of preoperative crystalline lens and early postoperative IOL in cataract patients.Methods:A self-control test was carried out in this study.109 cataract patients with 157 eyes(including 80 right eyes and 77 left eyes)received cataract surgery in the Affiliated Hospital of North Sichuan Medical College from March to July in 2020.CASIA2(Tomey,Japan)was used by the same examiner to measure the decentration and tilt of crystalline lens for three consecutive times under non-mydriatic conditions and mydriatic conditions,and the decentration and tilt of IOL were measured three times again one week later after phacoemulsification combined with aspheric IOL(SN60WF,Alcon,USA)implantation.Pearson correlation coefficient was used to detect the correlation between preoperative cataract lens and postoperative IOL.Results:There was no correlation of the decentration of preoperative crystalline lens and postoperative IOL in the right eye under non-mydriatic conditions(r=-0.031 P>0.05),and there was a positive correlation of the axis of decentration(r=0.482,P<0.01),tilt(r=0.54,P<0.01)and the axis of tilt(r=0.356,P<0.01).Under the condition of mydriasis,the decentration of crystalline lens and IOL showed weak correlation(r=0.263,P<0.05),and the axis of decentration r=0.337,P<0.01),tilt(r=0.562,P<0.01)and the axis of tilt(r=0.355,P<0.01)were positively correlated.At the same time,there was no correlation of decentration of preoperative crystalline lens and postoperative IOL in the left eye under non-mydriatic conditions(r=0.177,P<0.05),there was a medium correlation in tilt(r=0.444,P<0.01),and there was a good correlation of the axis of decentration(r=0.624,P<0.01)and the axis of tilt(r=0.906,P<0.01).There was no correlation of decentration of preoperative crystalline lens and postoperative IOL under mydriatic conditions.There was a strong positive correlation among the axis of decentration(r=0.645,P<0.01),tilt(r=0.553,P<0.01)and axis of tilt(r=0.927,P<0.01).Conclusion:Except for the decentration,there was a positive correlation of the the axis of decentration,tilt and the axis of tilt of preoperative crystalline lens and postoperative IOL measured by CASIA2.And the correlation of the axis of tilt was the best.Therefore,clinicians can estimate the position of postoperative IOL implantation to some extent according to the decentration and crystalline tilt of lens before cataract surgery,and choose a more suitable IOL for patients.Part Ⅲ The Relationship Between Visual Quality and Intraocular Lens Decentration and Tilt Measured by SS-OCT CASIA2Objective:To investigate the relationship between the visual quality and the measurement of IOL decentration and tilt after cataract surgery by a new swept-source anterior segment OCT CASIA2.Methods:An observational test was carried out in this study.A total of 90 eyes of 62 patients(43 right eyes and 47 left eyes)who underwent cataract surgery in the Affiliated Hospital of North Sichuan Medical College from March to July 2020 were included.One month after operation,the same skilled examiner used CASIA2 to measure the patients three consecutive times before and after mydriasis and the vector mean values were taken.Dual-channel optical quality analysis system(OQAS)and wavefront aberration instrument KR-1W were then used for the measurements.The Pearson correlation coefficient was used to test the correlation between the IOL decentration and tilt when the pupil was not dilated and the total high-order aberration(tHOA),spherical aberration(SA),coma,objective scatter index(OSI),modulation transfer function cutoff frequency(MTF cut off)and Strehl ratio(SR)in 4mm pupil diameter as well as the correlation between the IOL decentration and tilt when the pupil was dilated and tHOA,SA,coma,OSI,MTF cutoff,SR were also tested with a pupil diameter of 6mm.Results:There was no significant difference in the correlation of decentration and tilt of IOL,so the cross effect of decentration and tilt of IOL on visual quality could be ignored.When the pupil diameter was 4mm,IOL decentration was positively correlated with SA(r=0.347,P=0.001),OSI(r=0.343,P=0.002),and negatively correlated with MTF cut off(r=-0.244,P=0.032).There was no significant correlation between IOL decentration and tHOA,coma and SR.IOL tilt was negatively correlated with MTF cut off(r=0.-345,P=0.002)and SR(r=-0.256,P=0.023),but not with tHOA,SA,coma and OSI.When the pupil diameter was 6mm,there was no significant correlation between the decentration and tilt of IOL and tHOA,SA,coma,MTF cut off and SR.△OSI had a high positive correlation with OSI and a high negative correlation with MTF cut off.Conclusion:IOL decentration was positively correlated with SA and OSI,and negatively correlated with MTF cut off under the pupil diameter of 4mm.Although there was no statistical significance between IOL decentration and tHOA and SR.IOL tilt was negatively correlated with MTF cut off and SR,but was not correlated with tHOA,SA,coma and OSI.When the pupil diameter was 6mm,the decentration and tilt of IOL were not correlated with any of the above parameters.