Ophthalmology Department, Naval Medical Center, Naval Medical Center San Diego, San Diego, San Diego, California 92134-2202, USA.
J Cataract Refract Surg. 2012 Jul;38(7):1187-91. doi: 10.1016/j.jcrs.2012.02.037. Epub 2012 May 18.
To determine whether the correlation between corneal power (K) and axial length (AL) can be used for intraocular lens (IOL) power calculation when biometric data are incomplete.
Developing regions served by United States Navy humanitarian assistance missions.
Case series.
Measurements of K and AL were collected from all adult cataract surgery charts and used to calculate emmetropic IOL powers. A formula for estimating K or AL was derived by Deming regression analysis. The emmetropic IOL powers were calculated by hypothetical scenarios as follows: (1) K estimated from the formula and measured AL, (2) mean population K and measured AL, (3) measured K and estimated AL, and (4) measured K and mean population AL. The mean absolute refractive error (MAE) was calculated for each hypothetical scenario and an additional scenario (scenario 5) using single IOL power for all eyes. The MAEs were compared with a paired t test.
The formula derived from Deming regression analysis was K = 74.56 - 1.317 × AL. The MAE for the scenarios were (1) 0.90 diopters (D), (2) 1.11 D, (3) 1.91 D, (4) 1.55 D, and (5) 1.22 D. The MAE for scenario 1 was significantly less (P<.01) than that for scenarios 2 and 5. The MAE for scenario 5 was significantly less than that for scenarios 3 and 4.
The correlation between K and AL can be used to improve accuracy of IOL calculation when K is unavailable. When the AL is unavailable, the mean population IOL power is most accurate.
No author has a financial or proprietary interest in any material or method mentioned.
确定在生物测量数据不完整的情况下，角膜曲率（K）与眼轴（AL）之间的相关性是否可用于计算人工晶状体（IOL）的屈光力。
美国海军人道主义援助任务服务的发展中地区。
病例系列。
从所有成人白内障手术图表中收集 K 和 AL 的测量值，并用于计算正视 IOL 屈光力。通过 Deming 回归分析得出估计 K 或 AL 的公式。根据以下假设情况计算出正视 IOL 屈光力：（1）公式估计的 K 和测量的 AL，（2）平均人群 K 和测量的 AL，（3）测量的 K 和估计的 AL，以及（4）测量的 K 和平均人群 AL。为每个假设情况和使用所有眼睛的单一 IOL 屈光力的附加情况（情况 5）计算平均绝对屈光误差（MAE）。用配对 t 检验比较 MAE。
从 Deming 回归分析得出的公式为 K = 74.56 - 1.317 × AL。各假设情况的 MAE 分别为（1）0.90 屈光度（D），（2）1.11 D，（3）1.91 D，（4）1.55 D 和（5）1.22 D。情况 1 的 MAE 明显小于（P<.01）情况 2 和 5。情况 5 的 MAE 明显小于情况 3 和 4。
当 K 不可用时，K 与 AL 之间的相关性可用于提高 IOL 计算的准确性。当 AL 不可用时，平均人群 IOL 屈光力最准确。
没有作者在任何提到的材料或方法上有财务或专有利益。
