Effect of IOL's aspheric aberration on the quality of Vision after cataract surgery

Objective To evaluate whether the Tecnis Z9003 intraocular lens (IOL) (AMO) with a modified prolate anterior surface provides better quality of vision than a conventional spherical IOL (Aerosof Natural,Alcon)Methods In an intraindividual randomized study of 8 patients with bilateral cataract,in I eye the Z9003 IOL was implanted and in the other the Acrysof Natural SN60AT IOL.After 1 week and I month,the following investigations were performed: assessment of contrast sensitivity,C-Qnant straylight and Tracey aberration of each eye.Results The differences in the mean preoperative and postoperative spherical and astigmatic refractive errors and best corrected visual acuity between two groups were not statistically significant.Contrast sensitivity testing (at photopic condition) showed no apparent difference after surgery 1 week.At postoperative 1 month the eyes with Tecnis Z9003 IOL had better contrast sensitivity at all spatial frequencies,especially there were significantly better at 3,6 clad.Glaring test showed no more apparent between two IOLs.Wavefront measurements revealed spherical aberration in the Tecnis Z9003 IOL was less than Acrysof Natural IOL after surgery 1 week,significantly difference between two groups at 1 month.Conclusions The clinical results confirm the theory that spherical aberration of the eye after cataract surgery can be eliminated by modifying the anterior surface of the IOL.This leads to a significant impvoremant in contrast sensitivity and functional vision. Key words: Intraocular lens;  Contrast sensitivity;  Straylight;  Aberration;  Aspheric IOL