From the Ein-Tal Eye Center, Tel Aviv, Israel (Ton, Kleinmann, Levy, Assia); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel (Ton, Kleinmann, Assia); The Lions Eye Institute, Nedlands, Western Australia, Australia (Barrett); Centre for Ophthalmology and Visual Science, University of Western Australia, West Australia, Australia (Barrett); Department of Ophthalmology, Wolfson Medical Center, Holon, Israel (Kleinmann); Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel (Assia).
J Cataract Refract Surg. 2021 Nov 1;47(11):1389-1397. doi: 10.1097/j.jcrs.0000000000000638.
Intraocular lens (IOL) power calculation in eyes with keratoconus typically results in hyperopic postoperative refractive error. The purpose of this study was to investigate the visual and refractive outcomes in patients with keratoconus having cataract surgery with a toric IOL and compare IOL power calculation accuracy of conventional formulas and keratoconus-specific formulas.
Ein-Tal Eye Center, Tel-Aviv, Israel.
Retrospective case-series study.
Postoperative visual acuity and manifest refraction were examined. The error in predicted refraction and IOL power calculation accuracy within a range of 0.50 to 2.00 diopters (D) were compared between different IOL calculating formulas.
32 eyes with keratoconus were included. Visual acuity improved in all cases, and subjective astigmatism decreased from -2.95 ± 2.10 D to -0.95 ± 0.80 D (P < .001). The mean absolute errors were as follows: Barrett True-K formula for keratoconus with measured or predicted posterior corneal power, 0.34 D; Barrett Universal II formula, 0.64 D; Kane formula, 0.69 D; Kane formula for keratoconus, 0.49 D; SRK/T formula, 0.56 D; Haigis formula, 0.72 D; Holladay 1 formula, 0.71 D, and Hoffer Q formula, 0.87 D. Barrett True-K formula with measured posterior corneal power, SRK/T formula, and Kane formula for keratoconus resulted in a prediction error within ±0.50 D of 87.5%, 59.4%, and 53.1%, respectively.
Cataract removal with a toric IOL significantly improves visual acuity and decreases astigmatism in keratoconic eyes with a topographic central relatively regular astigmatic component. Keratoconus-specific formulas resulted in lower mean error in predicted refraction compared with conventional calculating formulas. Using the posterior corneal power within the Barrett True-K formula for keratoconus improved IOL power prediction accuracy.
在圆锥角膜患者中，进行人工晶状体（IOL）的屈光力计算通常会导致术后远视屈光不正。本研究的目的是探讨在伴有白内障的圆锥角膜患者中使用散光 IOL 进行手术的视觉和屈光效果，并比较常规公式和圆锥角膜专用公式在 IOL 屈光力计算中的准确性。
以色列特拉维夫的 Ein-Tal 眼科中心。
回顾性病例系列研究。
检查术后视力和主观验光。比较了不同 IOL 计算公式在 0.50 至 2.00 屈光度（D）范围内预测屈光度的误差和 IOL 屈光力计算的准确性。
共纳入 32 只圆锥角膜眼。所有病例的视力均有提高，主观散光从 -2.95 ± 2.10 D 降至 -0.95 ± 0.80 D（P <.001）。平均绝对误差如下：测量或预测后角膜曲率的 Barrett True-K 公式用于圆锥角膜，为 0.34 D；Barrett Universal II 公式，0.64 D；Kane 公式，0.69 D；Kane 公式用于圆锥角膜，0.49 D；SRK/T 公式，0.56 D；Haigis 公式，0.72 D；Holladay 1 公式，0.71 D，和 Hoffer Q 公式，0.87 D。Barrett True-K 公式测量后角膜曲率、SRK/T 公式和用于圆锥角膜的 Kane 公式的预测误差在±0.50 D 以内的比例分别为 87.5%、59.4%和 53.1%。
在伴有角膜地形图中央相对规则散光成分的圆锥角膜眼中，通过散光 IOL 去除白内障可显著提高视力并减少散光。与常规计算公式相比，圆锥角膜专用公式可降低预测屈光度的平均误差。在用于圆锥角膜的 Barrett True-K 公式中使用后角膜曲率可提高 IOL 屈光力预测的准确性。
