超声乳化白内障吸除术后角膜前后表面高阶像差的变化

目的 探讨利用Pentacam观察超声乳化白内障吸除术前后角膜前后表面高阶像差的变化.方法 前瞻性系列病例研究.对45例(51只眼)年龄相关性白内障患者行3.2 mm透明角膜切口的超声乳化白内障吸除联合折叠型人工晶状体植入术,分别于术前1 d,术后7 d、1个月及3个月利用Pentacam测量角膜前后表面的高阶像差(包括总的高阶像差、球差、彗差、三叶草以及3～6阶像差),将角膜前、后表面高阶像差按直径范围不同(3 mm直径和6 mm直径)分为两组,用具有一个重复测量的两因素设计定量资料方差分析方法对两组数据分别进行统计学分析.结果 角膜前表面总的高阶像差术前1 d为(0.289±0.171)μm,至术后3个月时轻度增加为(0.312±0.158)μm(3 mm直径);术前1 d为(0.980 ±0.215)μm,至术后3个月时轻度增加为(1.054±0.308)μm(6mm直径),但手术前后变化无统计学差异(F=1.55,P=0.22),且两组总的高阶像差随时间的变化趋势相同(F=0.95,P=0.42);其余各项高阶像差手术前后的变化与总的高阶像差的变化相似.角膜后表面总的高阶像差术前1 d为(0.548±0.220)μm,至术后3个月时明显增加为(0.661±0.275)μm(3 mm直径);术前1 d为(1.780±0.453)μm,至术后3个月时明显增加为(1.945±0.532)μm(6mm直径),手术前后变化差异有统计学意义(F=15.83,P=0.00),且两组总的高阶像差随时间的变化趋势不同(F=12.46,P=0.00);其余各项高阶像差手术前后的变化与总的高阶像差的变化相似.结论 超声乳化白内障吸除术后角膜前表面高阶像差的变化不影响术后患者的视觉质量.但是,手术前后角膜后表面高阶像差发生了显著的变化,可能影响术后患者的视觉质量.

Changes in high order aberrations of anterior and posterior surfaces of cornea before and after phacoemulsification

Objective To study the effects of phacoemulsification surgery on the optical high order aberrations(HOA)of the cornea measured with Pentacarm.Methods It was a prospective case series study.HOAs of the anterior and posterior surface of cornea were measured before and after phacoemulsification surgery on 51 eyes of 45 patients.Monofocal foldable IOLs were implanted afterphacoemulsification through a clear-cornea,3.2 mm incision without suture.Patients were observed 1 day before surgery,and at 7 days,1 month and 3 months after surgery.HOAs included the total high order aberration(tHOA),spherical aberration(SA),coma,trefoil,3rd,4th,5 th,6th order aberrations.Root-mean-square(RMS)values of HOAs were obtained with 3 mm and 6 mm aperture using corneal topography of Pentacam pre-and postoperatively,and were divided into 3 mm and 6 mm aperture groups.Aberrations were compared in each eye using repeated measures and the optical changes induced by surgery were investigated.Results The total HOA of the anterior surface increased slightly from a mean of(0.289±0.171)μm preoperatively to(0.312±0.158)μm postoperatively with 3 mm aperture;and(0.980±0.215)μm preoperatively to(1.054±0.308)μm postoperatively with 6 mm aperture,respectively.The increase was not statistically significant(F=1.55,P=0.22),and the changing trend of the total HOA was similar between the two groups of 3 mm and 6 mm aperture(F=0.95,P=0.42).The changes of other HOAs were similar to the total HOA pre-and postoperative.The total HOA of the posterior surface increased significantly from(0.548±0.220)μm preoperatively to(0.661±0.275)μm postoperatively with 3 mm aperture,and(1.780±0.453)μm preoperatively to(1.945±0.532)μm postoperatively with 6 mm aperture.The increase was statistically significant(F=15.83,P=0.00).The changing trend of the total HOA showed statistically difference between these two groups(F=12.46,P=0.00).The changes of other HOAs were similar to the total HOA pre-and postoperatively.Conclusions Phacoemulsification cataract surgery does not systematically degrade the optical quality of the anterior corneal surface.However,it introduces significant changes in most HOAs of the posterior surface of cornea,so the surgery may degrade the optical quality of the posterior corneal surface.