Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
Chin Med J (Engl). 2011 Dec;124(24):4260-3.
Corneal curvatures measured by conventional instruments after refractive surgeries were greater than the real values. This study on the instruments and methods for measuring corneal curvature was carried out with the aim of determining an accurate, simple and effective method to evaluate corneal refractive power after radial keratotomy (RK).
A retrospective study was carried out on 52 eyes of 42 patients with a history of RK. The postoperative measurements after RK were performed with a manual keratometer (Rodenstock, Munchen-Hamburg, Germany), a corneal topographer (Tomey TMS-1) and an automated IOLMaster keratometer (Carl Zeiss GmbH, USA). The results obtained from analyzing clinical histories (clinical history method, CHM) were compared to the postoperative measurements with a two-way analysis of variance. Adjusted keratometry was used to correct the corneal central refractive power (K) values of the three keratometers. The CHM results were also compared to the corrected K values obtained with the three keratometers using the same statistical method.
The smallest mean value was found for the CHM ((36.61 ± 2.23) diopters). The K values obtained with the CHM were very different from the results obtained with the three different instruments. The corrected K values obtained with the IOLMaster were the closest to the K values from the CHM.
It was shown that K values from measurements with the three instruments were higher. When the power of the intraocular lens of the patients after RK was calculated, the errors of the K values measured with the instruments should be taken into consideration.
屈光手术后，传统仪器测量的角膜曲率大于真实值。本研究旨在探讨角膜曲率测量仪器和方法，以确定一种准确、简单、有效的方法，用于评估放射状角膜切开术（RK）后角膜的屈光力。
对 42 例（52 只眼）RK 术后患者的临床资料进行回顾性研究。采用手动角膜曲率计（德国罗敦斯德公司，慕尼黑-汉堡）、角膜地形图仪（日本拓普康 Tomey TMS-1）和全自动 IOLMaster 角膜曲率计（德国卡尔蔡司公司）分别对 RK 术后患者进行测量。通过对临床病历（临床病历法，CHM）的分析结果与两种方差分析的术后测量结果进行比较。采用调整角膜曲率的方法对三种角膜曲率计的角膜中央屈光力（K）值进行校正。采用相同的统计学方法比较 CHM 结果与三种角膜曲率计校正后的 K 值。
CHM 的平均测量值最小（（36.61±2.23）D）。CHM 测量的 K 值与三种不同仪器的结果有很大差异。IOLMaster 得到的校正 K 值与 CHM 的 K 值最接近。
三种仪器的测量 K 值均偏高。在计算 RK 术后患者人工晶状体的屈光力时，应考虑仪器测量 K 值的误差。
