The comparison of visual quality following cataract surgery with aspheric and spherical intraocular lens implantation

Objective To assess the visual quality in eyes having cataract surgery and implantation of aspheric negative-aberration intraocular lens （IOL）. Methods This randomized prospective clinical study included 152 eyes of 112 patients having phacoemulsification and implantation of foldable intraocular lens. Patients were randomly divided into three groups depending on the type of the IOL implanted： Tecnis Z9003,Acrysof IQ or HQ. Visual acuity including uncorrected visual acuity （UCVA） and best-corrected visual acuity （BCVA）, contrast sensitivity and ocular wavefront aberration were evaluated 1 week, 1 month, and 3 months postoperatively. Contrast sensitivity testing was determined under photopic （85 cd/m2） and mesopic （3 cd/m2） conditions with no glare and with glare. Wavefront analysis of spherical aberration （SA）, root mean square （RMS） of Zernike orders （3rd-, 4th-, 5th-order RMS）, total higher-order aberration （HOA） RMS and total ocular aberration （TOA） RMS were performed. Results The two aspheric IOL groups and the spherical IOL group did not differ in UCVA and BCVA at three follow-up visits. At 1 week and 1 month postoperatively, there was no evidence of a statistically significant improvement resulting in photopic contrast sensitivity from implantation of these two aspheric IOLs. However, these two aspheric IOLs groups showed better results at low and intermediate spatial frequencies in mesopic contrast sensitivity at 1 month and 3 months postoperatively, and they also present statistically significant differences under photopic conditions with no glare and with glare at 3 months postoperatively. In addition, patients with one of the two aspheric IOLs had less SA, 4th-order RMS at the 3 follow-up visits, less HOA RMS at 1, 3 month postoperatively, and less TOA RMS at 6mm pupil diameter, when compared to those patients with spherical IOL. Conclusions In our study, aspheric IOLs （Tecnis Z9003 and AcrySof IQ） implantation led to improved contrast sensitivity and significant reduction of postoperative ocular SE and HOA. Negative aberration aspheric IOL may apply better quality of vision than conventional spherical IOL. Key words: Cataract;  Negative aberration;  Aspheric intraocular lens;  Contrast sensitivity;  Wavefrontaberration