Jin Haiying, Rabsilber Tanja, Ehmer Angela, Borkenstein Andreas F, Limberger Il-Joo, Guo Haike, Auffarth Gerd U
International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Germany.
J Cataract Refract Surg. 2009 Apr;35(4):650-62. doi: 10.1016/j.jcrs.2008.12.015.
To compare the accuracy of the thin-lens and ray-tracing methods in intraocular lens (IOL) power calculations in normal eyes and eyes after corneal refractive surgery.
International Vision Correction Research Centre, University of Heidelberg, Heidelberg, Germany.
Pseudophakic eye models were constructed using Zemax optical software, importing corneal radii (normal ray tracing) and corneal surface elevation data (individual ray tracing) measured by Pentacam Scheimpflug photography. Algorithms to predict IOL position (effective lens position [ELP]) or postoperative anterior chamber depth [ACD(post)]) (Haigis, Hoffer Q, Norrby, Olsen 2) were used in the thin-lens and ray-tracing methods. Intraocular lens power was calculated in 25 eyes after corneal refractive surgery using normal and double-K modified thin-lens and ray-tracing methods.
Back-calculation of ELP and ACD(post) were well correlated. Using algorithms of Haigis, Hoffer Q, Norrby, and Olsen 2 to predict IOL position, mean absolute prediction errors (MAEs) of the thin-lens formula were 0.64 diopters (D) +/- 0.52 (SD), 0.57 +/- 0.46 D, 0.59 +/- 0.42 D, and 0.61 +/- 0.47 D, respectively; MAEs of normal ray-tracing method were 0.64 +/- 0.50 D, 0.58 +/- 0.44 D, 0.59 +/- 0.41 D, and 0.62 +/- 0.45 D, respectively; MAEs of individual ray-tracing method were 0.66 +/- 0.52 D, 0.59 +/- 0.45 D, 0.59 +/- 0.43 D, and 0.62 +/- 0.50 D, respectively. No statistical differences were found between the thin-lens and ray-tracing methods.
Theoretical thin-lens formulas were as accurate as the ray-tracing method in IOL power calculations in normal eyes and eyes after refractive surgery.
比较薄透镜法和光线追踪法在正常眼及角膜屈光手术后眼的人工晶状体（IOL）屈光度计算中的准确性。
德国海德堡大学国际视力矫正研究中心。
使用Zemax光学软件构建假晶状体眼模型，输入通过Pentacam Scheimpflug摄影测量的角膜半径（正常光线追踪）和角膜表面高度数据（个体光线追踪）。在薄透镜法和光线追踪法中使用预测IOL位置（有效晶状体位置[ELP]）或术后前房深度[ACD（术后）]）的算法（Haigis、Hoffer Q、Norrby、Olsen 2）。使用正常和双K修正的薄透镜法及光线追踪法计算25只角膜屈光手术后眼的IOL屈光度。
ELP和ACD（术后）的反向计算相关性良好。使用Haigis、Hoffer Q、Norrby和Olsen 2算法预测IOL位置时，薄透镜公式的平均绝对预测误差（MAE）分别为0.64屈光度（D）±0.52（标准差）、0.57±0.46 D、0.59±0.42 D和0.61±0.47 D；正常光线追踪法的MAE分别为0.64±0.50 D、0.58±0.44 D、0.59±0.41 D和0.62±0.45 D；个体光线追踪法的MAE分别为0.66±0.52 D、0.59±0.45 D、0.59±0.43 D和0.62±0.50 D。薄透镜法和光线追踪法之间未发现统计学差异。
在正常眼及屈光手术后眼的IOL屈光度计算中，理论薄透镜公式与光线追踪法一样准确。
