Hwey-Lan Liou模型眼中Toric人工晶状体旋转对成像质量的影响

背景 目前关于Toric人工晶状体(IOL)旋转造成散光残留的研究较多,但其对成像质量和波前像差带来的影响尚不清楚. 目的 评价Toric IOL旋转对成像质量、波前像差及球镜和柱镜度残留的影响. 方法 将+22.0 D T3、T4、T5型Toric IOL分别植入Hwey-Lan Liou精密模型眼,IOL后表面平坦轴置于X轴,陡峭轴置于Y轴,在波长为550 nm的单色光和瞳孔直径4 mm条件下采用Zemax光学设计软件模拟带有Toric IOL的角膜散光模型眼.将Toric IOL分别旋转5°和10°,分别测定Toric IOL在居中位及旋转位的调制传递函数(MTF)及离焦、散光、彗差、三叶草像差和球差,计算该条件下模型眼出现的球镜和柱镜的屈光误差. 结果 Toric IOL居中时角膜散光可完全矫正,T3、T4、T5型Toric IOL的MTF非常接近,随着Toric IOL旋转度变大,40 ～ 60 c/d高空间频率下成像质量明显下降,3种晶状体MTF曲线均逐渐下降,以散光度大的T5型Toric IOL下降最为明显.Toric IOL旋转后彗差、三叶草像差和球差无明显变化,但散光度和离焦均增加.Toric IOL旋转后残留散光度增加,同时球镜度增大.结论 Toric IOL植入后位置的旋转导致眼的成像质量下降,散光度较大的Toric IOL旋转引起的MTF曲线降低更为明显.Toric IOL的旋转主要造成散光和球镜度的增加,但高阶像差不受影响.

Optical performance of Toric intraocular lens rotation in Hwey-Lan Liou model eye

Background The residual astigmatism following Toric intraocular lens (IOL) rotation have received much attention.However,the variation of the optical performance and the wavefront abrrveation with Toric IOL rotation are unclear.Objective The aim of this study was to evaluate the optical performance,wavefront abrrveation and residual diopter spherical and cylinder lens with Toric IOL rotation.Methods T3,T4 and T5 Toric IOLs of +22.0 D were placed in Hwey-Lan Liou model eye respectively,with the posterior surface flat on the X axis and steep on the Y axis.Corneal astigmatism model was established by mimicing the model eye with Toric IOL using Zemax optical software.Then the Toric IOLs were rotated 5° to 10° individually under the 4 mm pupil diameter and 550 nm monochromatic light,and the image performance and wavefront abrrveation were recorded with all conditions,including modulation transfer function (MTF),out-of-focus aberration,astigmatism aberration,coma,trefoil aberration and spherical aberration.The refractive error of spherical power and cylinder power were calculated.Results Corneal astigmatism was fully corrected when Toric IOLs in the middle,and the MTF curves were near in T3,T4,T5 Toric IOLs.The image performance was worse under the high spatial frequency with the increase of rotation degrees of Toric IOLs,showing the gradually low of MTF curves,especially T5 Toric IOL.No obvious changes was seen in coma,trefoil aberration and spherical aberration after rotation of Toric IOLs,while out-of-focus aberration,astigmatism aberration were obviously increased.In addition,residual astigmatism and spherical error increase with the rotation of Toric IOLs.Conclusions Toricl IOL rotation leads to increase of astigmatism and spherical refractive error but not high order aberration.