Connell Benjamin J, Kane Jack X
Eye Surgery Associates, Melbourne, Victoria, Australia.
Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia.
BMJ Open Ophthalmol. 2019 Apr 1;4(1):e000251. doi: 10.1136/bmjophth-2018-000251. eCollection 2019.
To compare the accuracy of a new intraocular lens (IOL) power formula (Kane formula) with existing formulas using IOLMaster, predominantly model 3, biometry (measures variables axial length, keratometry and anterior chamber depth) and optimised lens constants. To compare the accuracy of three new or updated IOL power formulas (Kane, Hill-RBF V.2.0 and Holladay 2 with new axial length adjustment) compared with existing formulas (Olsen, Barrett Universal 2, Haigis, Holladay 1, Hoffer Q, SRK/T).
A single surgeon retrospective case review was performed from patients having uneventful cataract surgery with Acrysof IQ SN60WF IOL implantation over 11 years in a Melbourne private practice. Using optimised lens constants, the predicted refractive outcome for each formula was calculated for each patient. This was compared with the actual refractive outcome to give the prediction error. Eyes were separated into subgroups based on axial length as follows: short (≤22.0 mm), medium (>22.0 to <26.0 mm) and long (≥26.0 mm).
The study included 846 patients. Over the entire axial length range, the Kane formula had the lowest mean absolute prediction error (p<0.001, all formulas). The mean postoperative difference from intended outcome for the Kane formula was -0.14+0.27×1 (95% LCL -1.52+0.93×43; 95% UCL +0.54+1.03×149). The formula demonstrated the lowest absolute error in the medium axial length range (p<0.001). In the short and long axial length groups, no formula demonstrated a significantly lower absolute mean prediction error.
Using three variables (AL, K, ACD), the Kane formula was a more accurate predictor of actual postoperative refraction than the other formulae under investigation. There were not enough eyes of short or long axial length to adequately power statistical comparisons within axial length subgroups.
使用IOLMaster（主要是3型）、生物测量法（测量变量包括眼轴长度、角膜曲率和前房深度）以及优化的人工晶状体常数，比较一种新的人工晶状体（IOL）屈光度计算公式（凯恩公式）与现有公式的准确性。比较三种新的或更新的IOL屈光度计算公式（凯恩公式、希尔 - 径向基函数V.2.0公式和带新眼轴长度调整的霍拉迪2公式）与现有公式（奥尔森公式、巴雷特通用2公式、海吉斯公式、霍拉迪1公式、霍弗Q公式、SRK/T公式）的准确性。
对墨尔本一家私人诊所11年间接受平稳白内障手术并植入Acrysof IQ SN60WF IOL的患者进行了单名外科医生的回顾性病例审查。使用优化的人工晶状体常数，为每位患者计算每个公式的预测屈光结果。将其与实际屈光结果进行比较，得出预测误差。根据眼轴长度将眼睛分为以下亚组：短眼轴（≤22.0毫米）、中等眼轴（>22.0至<26.0毫米）和长眼轴（≥26.0毫米）。
该研究纳入了846名患者。在整个眼轴长度范围内，凯恩公式的平均绝对预测误差最低（p<0.001，所有公式）。凯恩公式术后与预期结果的平均差异为-0.14 + 0.27×1（95%下限-1.52 + 0.93×43；95%上限+0.54 + 1.03×149）。该公式在中等眼轴长度范围内显示出最低的绝对误差（p<0.001）。在短眼轴和长眼轴组中，没有公式显示出明显更低的绝对平均预测误差。
使用三个变量（眼轴长度、角膜曲率、前房深度），凯恩公式比其他所研究的公式更能准确预测实际术后屈光情况。短眼轴或长眼轴的眼睛数量不足，无法在眼轴长度亚组内进行充分有力的统计比较。
