方法：前瞻性研究。选取梅尔辛大学医学院诊断为白内障需接受白内障超声乳化联合人工晶状体植入术的患者45例52眼作为研究对象。散瞳前后，所有患者均接受术前角膜地形图测量，自动角膜曲率测量和生物特征测定。

结果：与散瞳前数值相比，散瞳后，自动角膜曲率计测得的水平曲率(K_h)明显更大，且生物超声波测定的前房深度明显更深。使用散瞳后测量计算得出的屈光度数植入人工晶状体屈光正常的几率明显较高。比较正视眼和屈光不正眼发现正视眼的前房深度明显更深。

结论：在人工晶状体屈光度计算中，角膜曲率测量与生物特征测量比公式计算更重要。如果采用接触技术进行生物超声波测定，须注意避免角膜压迫。在检测时，注意前房深度应随访，且可通过利用人工晶状体屈光度计算中的最大值将误差最小化。

METHODS: This prospective study included 52 eyes of 45 patients diagnosed with cataract and indicated for phacoemulsification with intraocular lens(IOL)implantation at the Faculty of Medicine of Mersin University. For each patient, preoperative corneal topography, autokeratometric measurements and biometric measurements were performed before and after pupil dilation.

RESULTS: K_h(horizontal)values obtained through autokeratometry and anterior chamber depth measured by biometric ultrasonography were significantly greater when pupils were dilated compared with values obtained when pupils were undilated. Implanting IOLs with power calculated using measurements taken during pupillary dilation resulted in a significantly higher rate of emmetropia. Comparison of emmetropic eyes and ametropic eyes showed significantly larger anterior chamber depth in emmetropic eyes.

CONCLUSION: Keratometric and biometric measurements are more important in IOL power calculation than the formula used. If biometric ultrasonography is performed using contact technique, care must be taken to avoid corneal compression. Anterior chamber depth should be followed during measurement, and the margin of error can be minimized by using the highest value obtained in IOL power calculation.