Study On The Changes Of Ocular Biological Parameters Before And After Cycloplegia And Effective Intraocular Lens Position In Patients With High Myopia Cataract

Objective:1.To observe the effects of cycloplegia on ocular biological parameters and IOL degree calculation in patients with high myopia cataract（HMC）.2.To explore the changes of effective intraocular lens position（ELP）in patients with HMC after surgery.Methods:Part I:Ninety-one eyes of axial HMC patients with nuclear gradingⅢ-Ⅳand fifty-nine eyes of age-related cataract（ARC）patients diagnosed in the First Affiliated Hospital of Bengbu Medical College from October 2020 to December 2022were selected.IOLMaster-700 was used to measure axial length（AL）,mean corneal curvature（Km）,anterior chamber depth（ACD）,lens thickness（LT）,white to white（WTW）and central corneal thickness（CCT）before and after cycloplegic.The IOL degree was calculated by SRK/T,Haigis and Barrett Universal II formula.The changes of eye parameters and IOL degree before and after cycloplegia were compared.Part Ⅱ:Fifty-one eyes of axial HMC patients and forty-six eyes of ARC patients who underwent phacoemulsification combined with intraocular lens implantation in the first part were selected.Uncorrected visual acuity（UCVA）and best corrected visual acuity（BCVA）were followed up 1 day,1 week,1 month and 3 months after surgery.At the same time,IOLMaster-700 was used to obtain the axial scan of the eye after surgery,and Image J image analysis software was used to manually measure the ELPs at each time point after surgery.The actual axial position change of IOL was calculated.Statistical methods:Statistical software SPSS 26.0 was used for analysis,the count data were expressed as example（%）,the intra-group and inter-group comparisons were performed by Chi-square test or Fisher’s exact test,the measurement data were expressed by mean±standard deviation,the comparison between the two groups was consistent with normal distribution and homogeneity of variance was performed by t test,and the comparison between multiple groups was performed by one-way analysis of variance.LSD was compared pairwise,and the test level wasα=0.05.Results:There were no significant differences in AL,Km,WTW and IOL degree calculated by three formulas before and after cycloplegia in HMC group（all P>0.05）.There were statistically significant differences in ACD,LT and CCT（all P<0.05）.There were no significant differences in AL,Km and IOL degree calculated by three formulas before and after cycloplegia in ARC group（all P>0.05）.There were statistically significant differences in ACD,LT,CCT and WTW（all P<0.05）.Before and after cycloplegia,there were no statistical significance in AL,Km,WTW,ACD,LT,CCT and the difference of IOL degree calculated by the three formulas between the two groups（all P>0.05）.Between SRK/T and Haigis,SRK/T and Barrett Universal II formulas,there were statistically significant differences in the number of patients in HMC group with IOL degree≥0.5D before and after cycloplegia（P<0.05）.Haigis compared with Barrett Universal II formula,there was no significant difference in the number of people with IOL degree≥0.5D before and after cycloplegia（P>0.05）.Pairwise comparison of the three formulas in ARC group showed no significant difference in the number of patients with IOL degree≥0.5D before and after cycloplegia（all P>0.05）.There were no significant difference in the number of people with IOL degree≥0.5D calculated by the three formulas before and after cycloplegia between the two groups（P>0.05）.Part Ⅱ:There were statistically significant differences in UCVA and BCVA at each follow-up time point between the two groups（all P<0.05）.There were no significant difference in UCVA and BCVA in the two groups at each follow-up time point（P>0.05）.There were significant differences in ELP and ELP_RMSbetween the two groups at each follow-up time point（P<0.05）.There were no statistically significant differences in ELP in the two groups at each follow-up time point（all P>0.05）,but ELP in both groups showed a slight advance from 1 day to 1 week after surgery and shifted slightly from 1 week to 1 month after surgery.Three months after surgery,it was basically stable.There were no significant difference in ELP before and after cycloplegia at each follow-up time point in the two groups（P>0.05）.Conclusion:Part I:Cycloplegia can affect the results of some biological parameters in patients with cataract.Compared with ARC patients,the proportion of large degree difference in HMC patients was larger.Cycloplegia is more likely to affect the Haigis and Barrett Universal II formulas.Part Ⅱ:Axial movement of ELPs and dioptric drift occurred in cataract patients after surgery.It was stable 3 months after surgery,and finally showed far-sighted drift.The influence of postoperative hyperopic drift should be considered in the selection of target diopter.HMC patients had more significant IOL axial movement and increased instability after surgery.