| ObjectiveTo discuss the change of contrast sensitivity (CS) after implantation of different kinds of intraocular lens (IOL) and compare three techniques to measure the optical aberrations of IOL eye: laser ray tracing (LRT), the Hartmann-Shack (H-S), and the spatially resolved refractometer (SRR).MethodsThe first part: 126 eyes undergone phacoemulsification with IOL implantation. Visual acuity all were over 0.8. Age of all the people were 29～76 years old. Based on different IOL, we divided them into 2 groups. One group was monofocal IOL group, containing 3 groups, which were conventional spherical IOL group, yellow IOL group, and aspherical IOL group. Another group was multifocal IOL group ,which contains 3 groups that they are refractive multifocal IOL group, the second-generation refractive multifocal IOL group, and diffractive multifocal IOL group. The distance visual acuity, near visual acuity and contrast sensitivity were observed 1 month later after operation. The CS was measured using OPTEC 6500.The second part: 34 eyes after phacoemulsification with IOL implantation were involved in this study. Age of all the people were 50～80 years old. Uncorrected or corrected visual acuity all were over 0.8. The pupil diameter was 5mm in the dark room. All eyes were measured with all three techniques three months after cataract surgery at random order. We record Zernike coefficients, total RMS, and RMS of total high order aberration (HOA), coma, trefoil, and spherical aberration.ResultsThe first part: (1) The uncorrected distance visual acuity of the conventional spherical IOL group, the yellow IOL group, and the aspherical IOL group were respectively 1.01±0.18, 0.99±0.16 and 1.00±0.16. There were no statistically significant differences among groups (P>0.05). The uncorrected near visual acuity of them were 0.32±0.12, 0.34±0.11 and 0.36±0.11, which was also no statistically significant difference (P>0.05). (2) There were statistically significant difference in CS at distance between the aspherical IOL group and the conventional spherical IOL group in the daytime at 6, 12, 18cpd and in the day glare time at 3, 6, 12cpd (P<0.05). At night CS at distance in the aspherical IOL group was statistically different from that in the conventional spherical IOL group at 1.5, 6, 12cpd (P<0.05). There were no statistically significant difference between them it night glare time and and at near at any spatial frequency (P>0.05). There wre no statistically significant difference between the yellow IOL group and the conventional spherical IOL group (P>0.05), except for in night glare time at 1.5cpd (P<0.05). (3) The uncorrected distance visual acuity refractive MIOL group, the second-generation refractive MIOL group, and diffractive MIOL group were1.03±0.15, 1.02±0.20 and 1.03±0.13. The uncorrected near visual acuity of them were 0.71±0.23, 0.73±0.25 and 0.86±0.25; The distance-corrected near visual acuity of them were 0.58±0.20, 0.63±0.27 and 0.77±0.29. There were no statistically significant difference among three groups (P>0.05). (4) At distance or near, there were no statistically significant difference in CS among three MIOL groups in day or night at any spatial frequency(P>0.05). (5) There were statistically significant difference in the uncorrected near visual acuity between SIOL group and MIOL group(P<0.05), but no statistically significant difference in the uncorrected distance visual acuity (P>0.05). (6) The CS of MIOL group differed from SIOL group at 18cpd in the day with glare and at near and at 1.5, 12cpd in night with glare (P<0.05).The second part: (1) There were no statistically significant difference among three techniques in the RMS of total wave aberration, HOA, coma, trefoil and from 2 order to 6 order (P>0.05). The RMS of spherical aberration showed statistically significant difference between LRT and SRR (P<0.05), but no statistically significant difference both between LRT and H-S and between H-S and SRR (P>0.05). (2) There were statistically significant difference both between LRT and H-S and between H-S and SRR in Z3 (P<0.05). There were statistically significant difference among three techniques in Z4 (P<0.05). H-S significantly differed with SRR in Z6 and Z12 (P<0.05). LRT significantly differed with SRR in Z11 and Z20. The other else Zernike coefficients showed no statistically significant difference among them (P>0.05).Conclusion: (1) The aspherical IOL can improve contrast sensitivity compared with the conventional spherical IOL. The CS of the yellow IOL was similar with the conventional spherical IOL. (2) The distance visual acuity, near visual acuity and CS were similar after refractive and diffractive MIOL implantation. (3) MIOL can provide good distance and near visual acuity, however, the CS of MIOL group is inferior to SIOL group. (4) There were part difference of Zernike coefficients obtained by LRT, H-S and SRR. Thus, all three techniques provided information of wavefront aberration when applied IOL eye. However, the three methods are operationally different, and each has advantages and disadvantages depending on particular application. |
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