Evaluation of short-term visual quality following implantation of unsteady aberration aspheric intraocular lens / 中华实验眼科杂志

ABSTRACT

Background Cataract surgery with replacement of the natural lens with an artificial intraocular lens(IOL) has developed into refractive surgery.Visual acuity is not the only evaluation criterion,but more focus has been put into the visual quality postoperatively.Aspherical IOL could improve the visual quality by decreasing the aspherical aberration.Objective This study was to investigate the short-term visual acuity,aberration alteration and clinical application of unsteady aberration aspheric IOL.Methods A retrospective case-controlled study was designed.Forty-two eyes of 30 patients with age-related cataract were included and divided into two groups.Phacoemulsification combined with unsteady aberration aspheric IOL implantation was performed in 21 cataractous eyes of the ZO group,and phacoemulsification combined with spherical IOL implantation in the other 21 eyes of the ADAPT group.Visual acuity,best corrected visual acuity (BCVA),contrast visual acuity,spherical aberration of the whole eye,contrast sensitivity (CS),dare sensitivity,modulation transfer function (MTF) and apparent accommodation were measured three months after surgery.All the parameters were compared between the two groups.The correlation of CS with the root mean square of spherical aberration,root mean square of comatic aberration and age was analyzed by multiple linear regression analysis.Written informed consent was obtained from each patient prior to operation.Results No significant differences were found in unconnected visual acuity,BCVA and spherical degrees between the ZO group and ADAPT group 3 months after surgery(P＞0.05).The CS value in the ZO group was significantly higher than that of the ADAPT group under scotopic background condition with spatial frequencies of 6,12,18 cpd,low glare the spatial frequencies of 6,12 cpd,as well as high glare with 12,18 cpd(P＜0.05).Under a scotopic background with 100％ contrast or a photopic background with 5％ contrast,the contrast visual acuity of the ZO group was significantly higher than that of the ADAPT group (t =20.217,P =0.000 ; t =4.568,P =0.039).At pupil diameters of 3,4 and 5 mm,the Z4 value was significantly lower in the patients of the ZO group than that of the ADAPT group (U =63.000,P =0.000 ; U =52.000,P =0.000 ; U =36.000,P =0.000).However,no significant differences were seen in the Trefoil aberration (Z6)value at 3 mm and 4 mm of pupil diameter(U =204.000,P =0.678;U =215.000,P =0.890) and coma aberration (Z7,Z8) value at 3,4 and 5 mm of pupil diameter between ZO group and ADAPT group(Z7U=156.000,P =0.159 ; U =196.000,P =0.538 ; U =199.000,P =0.587 ; Z8U=163.000,P =0.148 ;U=214.000,P =0.870;U =143.000,P =0.061).When the pupil diameter was 5 mm,Z6 value was significantly lower in the patients of the ZO group than that of the ADAPT group (U =4.000,P =0.000).The higher-order aberration MTF was significantly elevated in the ZO group compared with the ADAPT group from 5 through 20 cpd at a pupil diameter of 4 mm (P＜0.05) and 10,20,25,30 cpd at a pupil diameter of 5 mm (P＜0.05).A slightly lower objective accommodation was found in the ZO group compared with the ADAPT group without statistically significant difference(t =0.003,P＞0.05).Multiple linear regression analysis showed that the change in CS was associated with the root mean square of the spherical aberration and IOL type(β=0.544,R2=0.519,P =0.000)rather than with the root mean square of the comatic aberration and age.Conclusions The postoperative visual quality in the unsteady aberration aspheric IOL implanted eye is superior to that in the spherical IOL implanted eye due to a reduction in spherical aberration.