Effect Of Phacoemulsification On High-order Aberrations Of Cornea And Study Of Visual Quality After Implantation Intraocular Lens

Objective:To study the effect of phacoemulsification surgery on the optical high order aberrations (HOAs) of the cornea measured with iTrace (Tracey Technologies Inc.USA). Compare the vision quality after implantation of aspherical intraocular lens (IOL):PY-60AD,Tecnis ZA9003,ADAPT-AO, in order to analysis how much spherical aberration retained for best visual quality.Methods:It was a prospective controlled clinical study. HOAs of the anterior surface of cornea were measured before and after phacoemulsification surgery on 50 eyes of 56 patients. Monofocal foldable IOLs were implanted after phacoemulsification through a clear-cornea,2.8mm incision without suture. Patients were seen 1day before surgery, and 7 days,1 and 3 months after surgery. HOAs include the total high order aberration (tHOA), spherical aberration (SA), coma, trefoil,3rd,4th,5th,6th order aberrations. Root-mean-square (RMS) values of HOAs were obtained with 3.0mm and 6.0mm aperture using iTrace pre- and postoperative, and were divided into 3.0mm and 6.0mm aperture groups. Aberrations were compared in each eye using repeated measures and the optical changes induced by surgery investigated.It was a retrospective clinical study.Select 107 patients 120 eyes that had cataract sugery with aspherical IOLs, according to IOL types,these patients were devided three groups:ZA9003 IOL group 35 patients 41 eyes, PY60AD IOL group 39 patients 43 eyes, ADAPT-AO IOL group 33 patients36 eyes. Uncorrected visual acuity, best corrected visual acuity(BCVA), total wavefront aberration and modulation transfer function(MTF) at six spatial frequencies were examined at 3 months postoperatively.Results:The SA of the anterior surface increased slightly from a mean of (0.027±0.037)μm preoperatively to (0.032±0.041)μm postoperatively with 3.0mm aperture, and (0.287±0.154)μm preoperatively to (0.298±0.224)μm postoperatively with 6.0mm aperture; the increase was not statistically significant (F=1.32, P=0.24), The changes of other HOAs and tHOA were similar to the SA pre- and postoperative.Three groups of uncorrected visual acuity, BCVA have not statistically significant differences (P>0.05)。Three groups of the high-order aberrations and MTF under six spatial frenquency of the eye have not statistically significant differences under 3.0mm aperture (P>0.05); Three groups of the high-order aberrations except spherical aberration of the eye have not statistically significant differences under 6.0mm aperture (P>0.05). Under 6.0mm aperture, the three groups of MTF have statistically significant differences when the spatial frenquency is 5cpd,lOcpd.,15cpd,20cpd (P<0.05); The differences are statistically significant when the spatial frenquency is 25cpd,30cpd,the values of MTF between PY-60AD and ZA9003,PY-60AD and ADAPT-AO(P<0.05); The differences are not statistically significant between ZA9003 and ADAPT-AO (P>0.05)Conclusion:Phacoemulsification cataract surgery does not systematically degrade the optical quality of the anterior corneal surface.Retaining 0.1um spherical aberration after implantation of aspherical IOL may improve the vision quality of patients.