Kim Seung Mo, Choi Joohyun, Choi Sangkyung
Department of Ophthalmology, Seoul Veterans Hospital, Seoul, Korea.
Korean J Ophthalmol. 2009 Mar;23(1):6-12. doi: 10.3341/kjo.2009.23.1.6. Epub 2009 Mar 9.
To evaluate the refractive predictability of a partial coherence interferometry (PCI) biometry device (IOL Master) for cataract surgery and to investigate factors that may affect it.
Retrospective review of 209 eyes from 151 patients that had undergone preoperative PCI biometry and an uneventful phacoemulsification cataract surgery with posterior chamber intraocular lens (IOL) implantation was conducted. Prediction error defined as the intended refraction minus the postoperative refraction in spherical equivalent (SE) and the absolute error were analyzed according to IOL calculation formulas, patient characteristics, preoperative visual acuity (VA) and refraction, posterior subcapsular cataract (PSC), signal-to-noise ratio (SNR), and axial length (AL).
The overall refractive predictability of the PCI device was good. Generally, the SRK/T formula performed better than the SRK-II formula. Refractive predictability was slightly worse in eyes with >or=+2.0 diopters (D) of preoperative SE (with both SRK-II and SRK/T) and in eyes with an AL<or=23.0 mm (only with SRK-II. No other factors significantly affected the refractive predictability of the PCI, although poor VA, dense PSC, and poor SNR were closely interrelated.
The SRK/T formula performed significantly better than the SRK-II formula. Eyes with an AL<or=23.0 mm were associated with significantly greater hyperopic shifts in postoperative refraction with the SRK-II formula, but not with the SRK/T formula. A preoperative SE>or=+2.0D was related to a significantly greater hyperopic shift in postoperative refraction. With proper verification of measured data and a suitable IOL calculation formula, good refractive predictability is expected from PCI biometry regardless of patient characteristics, preoperative VA, SNR, PSC, and AL.
评估用于白内障手术的部分相干干涉测量法（PCI）生物测量设备（IOL Master）的屈光预测性，并研究可能影响其的因素。
回顾性分析151例患者的209只眼睛，这些患者均接受了术前PCI生物测量，并顺利进行了超声乳化白内障吸除术及后房型人工晶状体（IOL）植入术。根据IOL计算公式、患者特征、术前视力（VA）和屈光状态、后囊下白内障（PSC）、信噪比（SNR）以及眼轴长度（AL），分析预测误差（定义为预期屈光度减去术后等效球镜度（SE）的屈光度）和绝对误差。
PCI设备的整体屈光预测性良好。一般来说，SRK/T公式的表现优于SRK-II公式。术前SE≥+2.0屈光度（D）的眼睛（使用SRK-II和SRK/T公式时）以及AL≤23.0 mm的眼睛（仅使用SRK-II公式时），其屈光预测性稍差。尽管视力差、PSC致密和SNR差密切相关，但没有其他因素显著影响PCI的屈光预测性。
SRK/T公式的表现明显优于SRK-II公式。使用SRK-II公式时，AL≤23.0 mm的眼睛术后屈光的远视偏移明显更大，但使用SRK/T公式时并非如此。术前SE≥+2.0 D与术后屈光的远视偏移明显更大有关。通过对测量数据进行适当验证并使用合适的IOL计算公式，无论患者特征、术前VA、SNR、PSC和AL如何，PCI生物测量法都有望实现良好的屈光预测性。
