Correlation Between Anterior Chamber Depth Change And Refractive Error After Cataract Surgery

Objective:In this study,we retrospectively analysed the relationship between changes in anterior chamber depth(ACD)and refractive error after cataract implantation with an intraocular lens(IOL)in order to improve the accuracy of preoperative calculation of IOL refraction.Methods:Eighty-one cataract patients who underwent cataract ultrasound emulsification combined with IOL implantation at Cangzhou People’s Hospital from March 2020 to October 2022 were selected for the study according to the inclusion criteria.The IOL Master was used to measure the ACD and calculate the IOL refraction,and the computerized automated optometry was used to measure the patients’ postoperative refraction.All patients used Barrett Universal II as the IOL degree calculation formula before surgery.All surgeries in this study were performed by the same specialist cataract surgeon in our hospital,and all IOLs were implanted in the lens capsule bag without incident.All ocular parameters and optometric data of the patients were collected preoperatively and at 1 day,1 month and 3months postoperatively.Cataract patients were divided into two groups,Group A(change in anterior chamber depth<0.11mm)and Group B(change in anterior chamber depth ≥ 0.11mm),according to the size of the change in anterior chamber depth after surgery(change in anterior chamber depth=0.11 mm was the median of the whole set of data).The relationship between postoperative anterior chamber depth change and postoperative refractive error in cataract patients was analysed by independent sample t-test;for preoperative anterior chamber depth,anterior chamber depth<2.95 mm was used as group a,i.e.shallow anterior chamber group,and anterior chamber depth ≥ 2.95 mm was used as group b,i.e.deep anterior chamber group(anterior chamber depth=2.95 mm was the median of the whole set of data).The relationship between preoperative anterior chamber depth and postoperative anterior chamber depth change and refractive error in cataract patients was analysed by independent samples t-test;the correlation between preoperative anterior chamber depth and postoperative anterior chamber depth change and refractive error was analysed by calculating Pearson’s correlation coefficient.All data were statistically analyzed using SPSS software 27.0.Results:1.The anterior chamber depths of cataract patients at 1 day,1 mont h and 3 months after surgery were 4.16±0.49 mm,4.29±0.47 mm and 4.30±0.49 mm,respectively,and a statistical difference(P<0.001)could be o btained by repeated-measures ANOVA for the first two comparisons an d no statistical significance(P=0.186)for the latter two comparisons,sugg esting that cataract ultrasound emulsification combined with IOL The a nterior chamber depth was basically stable 1 month after implantation;t he refractive error was-0.25(-0.50 to 0.00)D,+0.25(-0.13 to +0.50)D an d +0.25(-0.25 to +0.75)D at 1 day,1 month and 3 months after surgery,respectively,and there was a statistical difference between the data at 1day and 1 month,1 day and 3 month(P<0.001),and the comparison b-etween the data at 1 month and 3 months The data comparison was not statistically significant(P=0.647),suggesting that the refractive error was also basically stable at 1 month after cataract surgery.2.The refractive errors in Group A(ACD change<0.11mm)and Group B(ACD change ≥ 0.11mm)were +0.51 ± 0.44 D and-0.13 ± 0.73 D respectively,with a significant difference between Group A and Group B(P<0.001).This suggests that patients with small changes in anterior chamber depth after cataract surgery tend to experience hyperopic drift in refractive error,whereas patients with large changes in anterior chamber depth tend to experience myopic drift in refractive error.3.The postoperative ACD changes were 0.18 ± 0.11 mm and 0.09 ±0.07 mm in group a(preoperative ACD<2.95mm)and group b(preoperative ACD ≥ 2.95mm)respectively,with statistically significant differences between the two groups(p<0.001).The postoperative refractive errors were-0.37±0.46 D and +0.72±0.48 D,respectively,with a statistically significant difference between the two data sets(P<0.001).This indicates that the amount of postoperative anterior chamber depth change is greater in cataract patients with shallow preoperative anterior chamber,which tends to be myopic drift,while the amount of postoperative anterior chamber depth change is smaller in patients in the deep preoperative anterior chamber group,which tends to be hyperopic drift.4.The preoperative anterior chamber depth and postoperative anterior chamber depth change were negatively correlated(P<0.001)with a correlation coefficient of-0.385;the preoperative anterior chamber depth and postoperative refractive error were positively correlated(P<0.001)with a correlation coefficient of 0.742;the postoperative anterior chamber depth change and postoperative refractive error were negatively correlated(P<0.001)with a correlation coefficient of-0.488.This indicates that cataract patients the shallower the preoperative anterior chamber the greater the postoperative change in anterior chamber depth and the more the refractive error tends to drift towards myopia.Conclusion:1.The anterior chamber depth and refractive status are basically stable 1month after cataract surgery.2.Patients with shallow anterior chamber depth have a greater amount of change in anterior chamber depth postoperatively,tending towards a myopic drift of refractive error,while patients with deeper anterior chamber depth preoperatively have a smaller amount of change in anterior chamber depth postoperatively,tending towards a hyperopic drift of refractive error.