高度远视白内障患者人工晶状体屈光度数计算公式的选择

Selection of accurate IOL formula in patients with cataract and high hyperopia

目的比较Haigis、SRKⅡ、Hoffer Q、Hollady、SRK／T公式的准确性，以期为高度远视白内障患者植入的人工晶状体（IOL）屈光度数计算提供参考。方法比较性研究。分析了24例（31只眼）行超声乳化白内障吸除联合后房型人工晶状体植入术的高度远视白内障患者，术前分别应用A超和IOLMaster测量眼轴长度，计算人工晶状体度数，术后验光获得实测屈光度数。比较应用IOLMaster测量时Haigis、SRKⅡ、Hoffer Q、Hollady、SRK／T公式预测植入人工晶状体屈光度数的准确性，以及两种生物测量方法对各公式预测误差的影响。两种测量方法间的比较采用配对t检验。结果（1）应用IOLMaster测量时，Haigis公式的平均预测误差最小（0．37±0．14），随后依次为HofferQ、Hollday、SRK／T、SRKⅡ公式，分别为-0．70±0．12，-0．97±0．15，-1．25±0．14，-1．464-0．13。Haigis公式引起轻度的过矫，而其他公式则产生不同程度的欠矫。（2）A超的预测误差偏向正值，而IOL Master的预测误差却偏向负值。在A超测量眼轴时，HofferQ公式较为精确（-0．39±0．16），而在使用IOL Master时，Haigis更为精确（0．37±0．1d）。结论高度远视白内障患者选择IOL屈光度数的计算公式，使用IOL Master测量时，建议选择Haigis公式，而采用A超测量时，选择Hoffer Q公式则能获得较为准确的IOL屈光度数。

Objective To audit intraocular lens （IOL） power predictions for cataract surgery in high hyperopia by comparing the accuracy of different formulae of Haigis, SRK Ⅱ , Hoffer Q, Hollady, and SRK/T. Methods A comparative study was used in 31 eyes with cataract and high hyperopia underwent phacoemulsification and posterior chamber IOL implantation. Eyes were examined with A-scan and IOL Master before the operation. Postoperative refraction was examined 3 months after surgery. We compared the accuracy of prediction between these different formulae using IOL Master, and then compared the errors using the two different methods for axial length measurement. Results （ 1 ） Using IOL Master, the Haigis formula showed the smallest mean prediction errors （0. 37± 0. 14 ）, followed by the Hoffer Q, Holladay, SRK/T, and SRK Ⅱ formulae（ - 0.70 ± 0. 12, - 0.97 ± 0.15, - 1.25 ± 0. 14, - 1.46 ± 0.13 ）. The Haigis formula generated a slightly myopic result, but the other formulae generated hyperopic result at different degrees. （2） The A-scan led to a prediction error that was toward positive values （ equivalent to underestimating axial length） ,whereas the IOL Master error was towards the negative. Hoffer Q formula appeared to be more accurate when measuring axial lengths with A-Scan, whereas Haigis formula was more accurate when combined with IOL Master（0. 37 ± 0.14）. Conclusions For selection of IOL formula in cataract patients with high hyperopia,the Haigis would be the most accurate in IOL Master analysis,but the Hoffer Q was better when using A-scan.