Kohnen T, Klaproth O K
Klinik für Augenheilkunde, Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, 60590, Frankfurt, Deutschland.
Ophthalmologe. 2008 Mar;105(3):234-40. doi: 10.1007/s00347-008-1718-y.
Over the last years, the implantation of intraocular lenses (IOLs) has become a safe, effective, stable, and well-predictable procedure of lens replacement surgery. Therefore, manufacturers and surgeons have given special attention to the optical quality these lenses can achieve. Because spherical aberration of the natural lens changes in life from negative to positive values and hence impairs optical quality, implanting an aspheric IOL based on the young natural lenses' asphericity parameters, inducing negative, neutral, or individual spherical aberration, should improve the optical quality. Parameters used to evaluate optical quality are visual acuity, contrast sensitivity, glare disability, night vision, higher-order aberrations, and subjective questionnaires.
This article provides a survey of different kinds and principles of aspheric IOLs, current trials, and criteria used to estimate lens benefits.
Benefits of aspheric lenses have been shown in several studies. However, adjustment of the cornea's positive spherical aberration by an aspheric IOL can be demonstrated only in larger pupils. For young patients with distinctly larger mesopic and scotopic pupils who undergo refractive lens exchange, aspheric IOLs should be implanted. As higher-order and lower-order aberrations of the eye interact with each other, this fact will have to be taken into consideration when correcting spherical aberration. Spherical aberrations differ interindividually; therefore, individualisation of asphericity may be useful, either by choosing different IOLs depending on the eye's spherical aberration or by individual IOL surface design.
The use of aspheric IOLs for lens replacement reduces spherical aberration and therefore improves the optical quality of the eye.
在过去几年中，人工晶状体（IOL）植入已成为一种安全、有效、稳定且可良好预测的晶状体置换手术。因此，制造商和外科医生特别关注这些晶状体所能达到的光学质量。由于天然晶状体的球差在生命过程中从负值变为正值，从而损害光学质量，基于年轻天然晶状体的非球面参数植入非球面IOL，诱导负、中性或个体球差，应可改善光学质量。用于评估光学质量的参数包括视力、对比敏感度、眩光残疾、夜间视力、高阶像差和主观问卷。
本文综述了不同类型和原理的非球面IOL、当前的试验以及用于评估晶状体益处的标准。
多项研究已显示非球面晶状体的益处。然而，非球面IOL对角膜正球差的调节仅在较大瞳孔时才能得到证实。对于接受屈光性晶状体置换且中视和暗视瞳孔明显较大的年轻患者，应植入非球面IOL。由于眼睛的高阶和低阶像差相互作用，在矫正球差时必须考虑这一事实。球差存在个体差异；因此，非球面个体化可能有用，可根据眼睛的球差选择不同的IOL或通过个性化的IOL表面设计来实现。
使用非球面IOL进行晶状体置换可减少球差，从而提高眼睛的光学质量。
