From the The Queen Elizabeth Hospital (Sheen Ophir, LaHood, Goggin), Adelaide, The University of Adelaide (LaHood, Goggin), Adelaide, The South Australian Institute of Ophthalmology (LaHood, Goggin), Adelaide, and Ashford Advanced Eye Care (Goggin), Adelaide, Australia.
J Cataract Refract Surg. 2020 May;46(5):688-693. doi: 10.1097/j.jcrs.0000000000000162.
To establish whether toric intraocular lens (IOL) calculation on the basis of anterior corneal measurements alone, in corneas with oblique anterior astigmatism, will result in a systematic overcorrection or undercorrection of postoperative refractive astigmatism, and to establish whether adjustment of oblique anterior corneal astigmatism to allow for the likely effect of posterior corneal astigmatism is needed in such eyes.
The Queen Elizabeth Hospital, Department of Ophthalmology, Adelaide, South Australia.
Retrospective case series.
Data were collected from consecutive eyes with oblique anterior corneal astigmatism undergoing cataract surgery or refractive lens exchange. Toric IOL calculations were made using unadjusted anterior corneal astigmatism measurements and an astigmatically neutral technique. By comparison of targeted vs achieved astigmatic correction using vector analysis, the astigmatic power prediction error and angle of error were derived.
In 50 eyes, the mean postoperatively measured refractive astigmatism was 0.42 diopters (D) (SD 0.33 D), the mean targeted refractive astigmatism was 0.15 (SD 0.18), and the vector-derived mean absolute prediction error was 0.23 D (SD 0.21). All 50 eyes (100%) fell at or within ±1.00 D of the target and 45 eyes (90%) at or within ±0.50 D. The geometric mean astigmatism correction index was 0.98, and the mean absolute angle of error was 8.63 degrees (SD 8.55).
There is no systematic error attributable to posterior corneal astigmatism in toric IOL calculation and no need for adjustment of anteriorly measured corneal keratometric values for toric IOL calculation in eyes with oblique anterior corneal astigmatism. To do so may introduce an error in astigmatic outcome.
确定在具有斜向角膜前散光的角膜中，仅基于前角膜测量值进行的 toric 人工晶状体（IOL）计算是否会导致术后屈光性散光的系统过矫或欠矫，并确定在这些眼中是否需要调整斜向角膜前散光以考虑到后角膜散光的可能影响。
南澳大利亚阿德莱德伊丽莎白女王医院眼科。
回顾性病例系列。
从接受白内障手术或屈光性晶状体置换的具有斜向角膜前散光的连续眼中收集数据。使用未经调整的前角膜散光测量值和具有散光中和技术的 toric IOL 计算。通过向量分析比较目标与实现的散光矫正，得出散光力预测误差和误差角度。
在 50 只眼中，术后测量的屈光性散光平均值为 0.42 屈光度（D）（标准差 0.33 D），目标屈光性散光平均值为 0.15（标准差 0.18），向量分析得出的平均绝对预测误差为 0.23 D（标准差 0.21）。所有 50 只眼（100%）均在目标值的±1.00 D 以内，45 只眼（90%）在目标值的±0.50 D 以内。几何平均散光矫正指数为 0.98，平均绝对误差角度为 8.63 度（标准差 8.55）。
在 toric IOL 计算中，不存在归因于后角膜散光的系统误差，也无需为斜向角膜前散光的 toric IOL 计算调整前角膜角膜曲率计测量值。这样做可能会导致散光结果出现误差。
