Razmjoo H, Peyman A, Kashfi A, Peyman M, Dehghani A
Isfahan University of Medical Sciences and Health Services, Feiz Eye Hospital, Isfahan, Iran.
Eur J Ophthalmol. 2006 Jul-Aug;16(4):525-9. doi: 10.1177/112067210601600404.
To find a method of calculating intraocular lens (IOL) power that may be independent of preoperative data in eyes that have previously undergone myopic laser in situ keratomileusis (LASIK).
In 148 eyes of 75 patients, before and 6 months after LASIK, IOL power was calculated with SRK/T formula utilizing the spherical equivalent as the desired target refraction. Assuming that LASIK does not alter the crystalline lens refractive properties, IOL calculation error (CER) was estimated with this formula: CER = [pre-LASIK IOL power]/[post-LASIK IOL power]. Then the authors used postoperative biometry and Orbscan II corneal topography data in multiple regression models to find the best variables to predict the CER. Predicted amount of error which is calculated independent of preoperative data could be used to correct the post-LASIK calculated IOL: [corrected post-LASIK IOL power] = CER x [post-LASIK IOL power].
A regression model with these predictors was found: axial length in millimeters (L), radius of the anterior corneal surface best fitted sphere in millimeters divided by radius of the posterior corneal surface best fitted sphere in millimeters (AntBFS/PostBFS), corneal central 5 millimeters mean power in diopters divided by corneal central 3 millimeters mean power in diopters (mean 5 mm/mean 3 mm), the post-LASIK IOL power, and the post-LASIK simulated K reading. The model R square was 0.88.
There is correlation between post-LASIK biometry values and IOL power correction factor. This study presents a new model for further investigation.
寻找一种计算人工晶状体（IOL）度数的方法，该方法可能独立于先前接受过近视激光原位角膜磨镶术（LASIK）的眼睛的术前数据。
在75例患者的148只眼中，在LASIK术前和术后6个月，使用SRK/T公式以等效球镜度作为期望的目标屈光不正来计算IOL度数。假设LASIK不改变晶状体的屈光特性，用此公式估计IOL计算误差（CER）：CER = [LASIK术前IOL度数]/[LASIK术后IOL度数]。然后作者在多元回归模型中使用术后生物测量和Orbscan II角膜地形图数据来寻找预测CER的最佳变量。独立于术前数据计算出的预测误差量可用于校正LASIK术后计算的IOL：[校正后的LASIK术后IOL度数] = CER×[LASIK术后IOL度数]。
发现了一个具有以下预测因素的回归模型：以毫米为单位的眼轴长度（L）、前角膜表面最佳拟合球的半径（毫米）除以后角膜表面最佳拟合球的半径（毫米）（AntBFS/PostBFS）、角膜中央5毫米平均屈光力（屈光度）除角膜中央3毫米平均屈光力（屈光度）（平均5毫米/平均3毫米）、LASIK术后IOL度数以及LASIK术后模拟角膜曲率读数。该模型的决定系数R²为0.88。
LASIK术后生物测量值与IOL度数校正因子之间存在相关性。本研究提出了一个新的模型以供进一步研究。
