Comparison of visual quality between zero spherical aberration intraocular lens and spherical intraocular lens implanted eyes

Background Zero spherical aberration intraocular lenses(IOL)is designed to prevent the addition of positive spherical aberration after surgery.Research indicated that some positive spherical aberration can provide better depth distance of focus and pseudoaccommodation.Objective The present study was to compare the visual function and wavefront aberrations in pseudophakic eyes with zero spherical aberration IOL and spherical IOL.Methods A prespective case-controlled study was designed.Eighty eyes of 52 patients with age-related cataract were enrolled and divided into two matched groups based on random number table method.The regular phacoemulsification was performed on the eyes,and a zero spherical aberration IOL(Akreos AO)was implanted in the test group and a spherical IOL was used in the control group(Akreos Adapt IOL).The corrected distance visual acuity(CDVA),contrast sensitivity,depth of focus and wavefront aberrations were recorded and compared at 3 months after cataract surgery between these two groups.The trail was approved by the Ethic Committee of Eye Hospital of Wenzhou Medical College,and written informed consent was obtained from each patient prior to the program.Results The clinical demography from the two groups was matched(P ＞ 0.05).There were no significant difference in the CDVA (LogM AR)(-0.03 ±0.08 versus-0.02+0.10)(t =-0.50,P =0.61)and in depth of focus(3.48± 1.07 DS versus 3.20±0.77 DS)(t =1.15,P=0.25)between the zero spherical aberration IOL group and the spherical IOL group.The contrast sensitivities under the mesopic condition at 12.0 c/d and mesopic with glare at 3.0,6.0,18.0 c/d were 12.42 ± 13.16,42.58 ±24.96,30.19± 25.64 and 3.03 ± 5.49 in the zero spherical aberration IOL group,and those in the spherical IOL group were 5.59 ± 8.11,28.74 ± 18.69,17.07 ± 19.35 and 0.22 ± 1.15 without significant differences between these two groups(P＜0.05).Under the 5.0 mm pupil analyzing zone,the spherical aberration in zero spherical aberration IOL group was(0.13 ±0.07)μm,showing a significant reduction in comparison with spherical IOL group(0.21 + 0.07 μm)(P ＜ 0.05).No evidently differences were found in total high-order aberration,coma aberration and trefoil aberration(P＞0.05),but the sphere aberration was considerably lower in the zero spherical aberration IOL group compared with spherical IOL group(t=-4.19,P＝0.00).Conclusions The visual quality of the eyes implanted zero spherical aberration IOL is significantly better than ones implanted with spherical IOL. Key words: Lens/intraocular;  Aspheric ;  Wavefront aberration ;  Constrast sensitivity ;  Visual acuity