Gargallo Diana, Remón Laura, Ares Jorge, Castro-Alonso Francisco J
Department of Applied Physics, University of Zaragoza, Zaragoza, Spain.
UFR, Department of Ophthalmology, University Hospital Miguel Servet, Zaragoza, Spain.
PLoS One. 2024 Dec 5;19(12):e0311566. doi: 10.1371/journal.pone.0311566. eCollection 2024.
Accurate alignment of Toric Intraocular Lens (T-IOLs) in cataract surgery is crucial for good visual outcomes. The purpose of this study was to evaluate the influence of rotation, axial shift and their combined effects on the refractive error and image quality of a wide range of T-IOL powers (from +1.50 D to +6.00 D cylinder) and two pupil diameters (3.34 and 4.44 mm).
Numerical ray tracing was utilized to quantify the residual error. Simulated retinal images and Visual Strehl (VS) ratios were calculated to evaluate image quality.
First, T-IOL rotation showed better agreement with Holladay's formula than 3.33% rule. Second, axial displacement resulted in acceptable residual cylinder (<0.50 D) across all examined cylinder powers. Third, concerning the combined effects, the influence of axial shift on residual cylinder becomes negligible when rotation errors exceed 2.5°. Fourth, a pupil-dependent nonlinear relationship was noted for image quality caused by both types of misalignment factors.
The 3.33% rule was confirmed as a reasonable approximation for the residual astigmatism caused by rotation of T-IOLs. The influence of axial shift on residual astigmatism becomes insignificant when there is also rotation. Image quality studies confirm that 30° of rotation are enough invalidate the compensation benefits of a T-IOLs in comparison with a Spherical Intraocular lens.
在白内障手术中，复曲面人工晶状体（T-IOL）的精确对准对于良好的视觉效果至关重要。本研究的目的是评估旋转、轴向移位及其联合效应对多种T-IOL屈光度（从+1.50 D到+6.00 D柱镜）和两种瞳孔直径（3.34和4.44 mm）的屈光不正和图像质量的影响。
采用数值光线追迹来量化残余误差。计算模拟视网膜图像和视觉斯特列尔（VS）比率以评估图像质量。
首先，T-IOL旋转与霍拉迪公式的一致性比3.33%规则更好。其次，轴向位移在所有检查的柱镜屈光度范围内产生了可接受的残余柱镜（<0.50 D）。第三，关于联合效应，当旋转误差超过2.5°时，轴向移位对残余柱镜的影响可忽略不计。第四，对于由两种类型的对准误差因素引起的图像质量，发现了一种与瞳孔相关的非线性关系。
3.33%规则被确认为T-IOL旋转引起的残余散光的合理近似值。当存在旋转时，轴向移位对残余散光的影响变得微不足道。图像质量研究证实，与球面人工晶状体相比，30°的旋转足以使T-IOL的补偿益处无效。
