Research On The Effects Of Different Factors For The Chromatic Aberration Of Intraocular Lenses

Objective:Compare the effect of chromatic aberration of intraocular lenses with different Abbe numbers, different refractive indices and different incident light waveband in IOL eye models. Investigate the IOL’s effect on chromatic aberration of different refrction of human eye, comparing the effect of chromatic aberration of central thickness of different diopter intraocular lenses. Do preliminary theory research for influence factors of chromatic aberration of the human eye.Methods:Computer numerical simulation experiment was used in our study. IOL eye model based on Liou-Brennan eye model was constructed by using ZEMAX optical design software. A+22D traditional typical spherical AR40e IOL(AMO company of America) was implanted in this eye model, and changing the Abbe number and refractive index respectively to construct different eye models. Monochromatic and polychromatic through focus modulation transfer function(MTF) values and curves with3mm pupil were recorded respectively, analyzing the effect on chromatic aberration IOLs’Abbe number and refractive index. Changing the incident light waveband, recording the MTF values and curves with3mm pupil for different diopter IOLs to analyze the effect of the incident light waveband on chromatic aberration of IOLs.IOL eye model based on Liou-Brennan eye model was constructed by using ZEMAX optical design software. Different diopter IOLs (traditional typical spherical IOL AR40e, AMO company of America) were implanted in this eye model. Monochromatic and polychromatic through focus modulation transfer function(MTF) values and curves with3mm pupil were recorded. The difference for chromatic aberration among different diopter IOL eyes was analyzed.Results:(1) When the other parameters were the same, the difference of the MTF values between the555nm monochromatic light and470-650nm polychromatic light reduced gradually with the Abbe number increasing under3mm pupil. The MTF values of IOL eye models changed a little under the555nm monochromatic light, however, the MTF values of IOL eye models increased with the Abbe number increasing with the difference between every two MTF curves obvious.(2) When the other parameters were the same, the difference of the MTF values between the555nm monochromatic light and470-650nm polychromatic light reduced gradually with the refractive index increasing under3mm pupil. The MTF values of IOL eye models increased with the refractive index increasing under the555nm monochromatic light. The MTF values of IOL eye models increased with the refractive index increasing, with the MTF value increasing, however, the increased MTF value gradually decreasing.(3) When all the parameters were the same, the MTF curves of the Liou-Brennan eye model under the incident light waveband510-650nm and470-650nm were all most the same. The MTF value of IOL eye models under the incident light waveband510-650nm was higher than that under the incident light waveband470-650nm, with only a little difference.(4) MTF values for555nm monochromatic light were higher than470-650nm polychromatic light under any spatial frequency at the range of0-60c/d when well focused at3mm pupil. The difference between the two MTF values increased with the increasing diopter. The a value decreased with the increasing diopter of the IOLs (the central thickness increasing, the axial length decreasing) when the spatial frequency was<12c/d, which means the effect of chromatic aberration on MTF decreases. However, the result was reverse when the spatial frequency was>15c/d. The a value increased with the increasing spatial frequency, which means the effect of chromatic aberration on MTF increases (a%=△MTF/MTF1,△MTF=MTF1-MTF2, MTF1was the MTF value for555nm monochromatic light, MTF2was the MTF value for470-650nm poluchromatic light).(5) MTF values for different diopter IOL eye models under555nm monochromatic light were lower than that of Liou-Brennan eye model under any spatial frequency at the range of0-60c/d when well focused at3mm pupil (with MTF value of the30D IOL eye model higher than that of Liou-Brennan eye model under the spatial frequency≥50c/d). The difference between every two MTF curves was obvious. The MTF values showed a increase trend with the increasing diopter of the IOLs. MTF values for different diopter IOL eye models under470-650nm polychromatic light were lower than that of Liou-Brennan eye model under any spatial frequency at the range of0-60c/d when well focused at3mm pupil. Compared with the555nm monochromatic light, the difference between every two MTF curves became smaller. The MTF values also showed a increase trend with the increasing diopter of the IOLs.Conclusion:The greater of the Abbe number and the smaller of the refractive index of the IOL was, the smaller of the chromatic aberration would be, which affected the visual quality less. The blue-light filtering IOL was equal to the non-blue-light filtering IOL of the effect on chromatic aberration of human eye.With the increasing of the IOLs’diopter, that was the increasing of the central thickness, the chromatic aberration of the IOL eye model, which was based on Liou-Brennan eye model, increased. The increased chromatic aberration decreased visual quality of human eye. The one who has a shorter axial length needs an IOL with smaller chromatic aberration to improve the postoperative visual quality.