Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstraße 8, 80336, Munich, Germany.
Institute of Experimental Ophthalmology, Saarland University, Saarbrücken, Germany.
Graefes Arch Clin Exp Ophthalmol. 2020 Feb;258(2):345-350. doi: 10.1007/s00417-019-04570-1. Epub 2019 Dec 20.
To evaluate refractive outcomes for a standard industry calculator using anterior corneal astigmatism or total corneal refractive power.
This prospective interventional study evaluated the refractive outcomes of 56 eyes using a standard industry calculator (Zeiss ZCalc) and a digital IOL alignment software. After A-constant optimisation the ZCalc was recalculated with two different keratometry values using appropriate refractive indices: anterior corneal astigmatism (ACA) by IOLMaster 700 and total corneal refractive power (TCRP) by Pentacam. The Barrett toric calculator was used as a reference.
Undercorrection of 0.04 ± 0.42 D after 1 week and 0.13 ± 0.48 D after 3 months was achieved for the spherical equivalent by using a standard industry calculator. IOL misalignment was 2.8° ± 3.4° using a digital alignment system. For the ZCalc, the mean absolute error could be reduced from 0.19 ± 0.40 D using ACA to 0.04 ± 0.48 D when considering total corneal refractive power (p = 0.06). The Barrett calculator delivered better refractive outcomes than using a standard industry calculator with ACA measurements only (- 0.06 ± 0.43 D; p < 0.01).
Reliable and accurate refractive outcomes in toric IOL calculation were achieved by using the ZCalc calculator. The prediction error for a widely used standard industry toric IOL calculator could be reduced by using measured total corneal refractive power.
评估使用前角膜散光或总角膜屈光力的标准行业计算器的屈光结果。
这项前瞻性干预研究使用标准行业计算器（蔡司 ZCalc）和数字人工晶状体对准软件评估了 56 只眼的屈光结果。在 A-常数优化后，使用适当的折射率，通过 IOLMaster 700 测量前角膜散光（ACA）和 Pentacam 测量总角膜屈光力（TCRP），重新计算 ZCalc 的两个不同角膜曲率值。使用 Barrett toric 计算器作为参考。
使用标准行业计算器，在 1 周时获得 0.04±0.42 D 的欠矫，在 3 个月时获得 0.13±0.48 D 的欠矫。使用数字对准系统，人工晶状体的不对准为 2.8°±3.4°。对于 ZCalc，使用 ACA 时平均绝对误差可从 0.19±0.40 D 降低到考虑总角膜屈光力时的 0.04±0.48 D（p=0.06）。与仅使用 ACA 测量值的标准行业计算器相比，Barrett 计算器提供了更好的屈光结果（-0.06±0.43 D；p<0.01）。
使用 ZCalc 计算器可以实现可靠和准确的 toric IOL 计算屈光结果。通过使用测量的总角膜屈光力，可以降低广泛使用的标准行业 toric IOL 计算器的预测误差。
