Effects Of Intraocular Lenses With Shift On Coma And Visual Quality In Human Eye Models

ObjectiveTo compare the effects of coma aberration of intraocular lens in different pupil sizes,with different refractive diopters or with different-designed optic curves in eye models with or without decentration or tilt.To analyze the influence factors of the coma aberration and its effects on visual quality,and the effects of various refractive diopters and pupil sizes on coma as well as the other aberrations.For the first time ever to find a way to reduce coma via different designed optic curves,and do preliminary theory study of the adverse effects brought by coma in human eye model.MethodsComputer numerical simulation experiment was used in our study.IOL eye model based on Liou-Brennan eye model,substituting the IOL data for the lens data,was established via Zemax optic system design software.10D?20D?30D IOLs with aspherical balance curve(the spherical aberration is-0.18)and a 22 D ordinary aspherical IOL(the spherical aberration is-0.27)were implanted in this eye model.The coma aberration and the MTF curve of all these eye model was recorded respectively under the 3mm-pupil-size and 6mm-pupil-size after simulating the IOLs with 0.4mm-decentration or 7-degree-tilt,in order to analyze the effects of different designed curves,different pupil sizes and different refractive diopters on coma and visual quality.\ResultsThe coma values of 20 D IOL with ABC were less than that of 22 D ordinary aspherical IOL,except in the situation that the IOL eye models with tilt under 3mm pupil size,where the two groups had no significant difference.As for MTF value and curve,there was no significant difference between the two IOLs without shifting under 3mm pupil size,however,22 D ordinary aspherical IOL had a better MTF curve under 6mm pupil size.Moreover,ordinary aspherical IOL showed a more significant decrease in MTF values and became worse than IOL with ABC when decentration or tilt happening.In addition,the decrease in MTF values was more significant under 3mm pupil size than 6mm.The coma values of the eye model increased with the diopter after the implantation of 10 D,20D and 30 D ABC-IOLs.The MTF value of the 10 D IOL was the lowest and 30 D was the best when there was neither decentration nor tilt.There is a significant decrease in the MTF curves with the pupil size changing from 3mm to 6mm.In addition,when the 0.4mm decentration happened,all of the three IOL in different diopters had the similardescend range in MTF curves,and the descend range was more fierce after changing the pupil size to 6mm.Furthermore,when the 7 degree tilt happened,the MTF values of 30 D IOL sharply decreased,at length 30 D IOL was the last one and 10 D the best.Conclusions1.Using the aspherical balance curve(ABC)design could effectively reduce coma aberration after shifting,and ensure a better visual quality.2.The effects of decentration of IOL is more significant than tilt.3.After IOL shifting,the coma aberration value increased with the diopter.4.After IOL tilt,the smaller diopter could provide better visual quality.