A study of the relationship between corneal Q value and selection of aspheric intraocular lens / 中华实验眼科杂志

ABSTRACT

Background Aspheric intraocular lens (IOL) is designed to reduce the spherical aberration of the eye after cataract surgery and to obtain better visual quality.However,the selection of a personalized aspheric IOL is a problem to be solved.Objective This study was to compare the wavefront aberration and quality of vision of patients between the implantation of negative spherical aberration IOL and non-aberration IOL,and to investigate the relationship between corneal Q values and postoperative spherical aberration.Methods One hundred and four eyes of 90 patients with age-related cataract were randomized into two groups.Fifty-two eyes of 46 patients who received a Tecnis Z9001 IOL implantation were assigned as the negative spherical aberration IOL group and 52 eyes of 44 patients who received Akreos AO IOL without aberration were assigned as the non-aberration IOL group.The preoperative corneal Q values were measured and the mean Q value(Q)was computed.Then the patients in the two groups were further divided into 2 subgroups,respectively,based on their Q values were over or below (Q）.The corneal Q values,root mean square(RMS) of ocular spherical aberration,coma and total higher-order aberrations(HOAs) for 5 mm diameter pupil,scotopic contrast sensitivity with or without glare at 6 mm pupil diameter were measured 3 months after surgery.Results The pre-and post-operative corneal Q values were insignificantly changed (t =1.447,P =0.151).The spherical aberration in the negative spherical aberration IOL group was(0.059-±0.047)μm,and that in the non-aberration IOL group was(0.110±0.066)μm,with a statistically significant difference between them (t =-4.567,P=0.000).Scotopic contrast sensitivities at intermediate and high frequencies were significantly better in the negative spherical aberration IOL group than in the non-aberration IOL group (t =2.495,t =2.359,P ＜ 0.05).There was no significant difference in coma and HOAs between the two groups after operation (P ＞ 0.05).Weak positive correlations were seen between the pre-and post-operative corneal Q values and spherical aberration in the two groups(r=0.277,0.292,0.285,0.325,all at P＜0.05).However,no significant differences were found in spherical aberration,contrast sensitivity and scotopic contrast sensitivity between the different subgroups (P ＞ 0.05).Conclusions Negative spherical aberration IOL has lower spherical aberration and better scotopic contrast sensitivity than non-aberration IOL.The results suggest that it may be not enough to choose the corneal Q value only as the single reference criterion for selection of aspheric IOL.