J Refract Surg. 2020 Jul 1;36(7):449-458. doi: 10.3928/1081597X-20200609-01.
To characterize the preoperative vectorial difference between manifest refractive astigmatism and anterior corneal astigmatism, termed ocular residual astigmatism (ORA), and to investigate its influence on topography-guided laser in situ keratomileusis (LASIK) outcomes.
Comparative retrospective analysis of 21,581 consecutive eyes treated on the manifest refractive astigmatism. Standard outcomes of the 7,180 eyes with the lowest ORA (first tercile: 0.35 ± 0.13 diopters [D]) were compared to the 7,208 eyes with the highest ORA (last tercile: 1.13 ± 0.25 D).
The ORA followed a right-skewed normal distribution (R = 0.99) with a mean ± standard deviation of 0.73 ± 0.36 D. The efficacy index of eyes with low versus high ORA was identical (0.98 ± 0.07 vs 0.98 ± 0.08; P = .99), with a similar percentage having a spherical equivalent within ±0.50 D of the intended target (94.7% vs 94.1%; P = .11). The safety index (1.00 ± 0.04 vs 1.00 ± 0.04; P = .99) and Alpins correction index (1.01 ± 0.37 vs 1.00 ± 0.43; P = .10) were identical. A greater number of eyes with high versus low ORA had postoperative residual astigmatism of 0.75 D or greater (6.1% vs 3.9%). Eyes with very high ORA (ORA ⩾ 1.50 D; 2.5% of the population) marginally reduced the efficacy index from 0.98 to 0.97 (P < .001).
The contribution of ORA to topography-guided clinical outcomes in most virgin eyes is negligible, with excellent efficacy, accuracy, and safety in both low ORA and high ORA groups. Myopic eyes with high ORA treated on the manifest refraction should not be excluded from topography-guided LASIK. [J Refract Surg. 2020;36(7):449-458.].
描述眼前部屈光性散光与角膜前散光之间的术前向量差异，即眼残余散光（ORA），并探讨其对基于地形图引导的准分子激光原位角膜磨镶术（LASIK）结果的影响。
对 21581 例连续接受治疗的患者的眼前部屈光性散光进行了回顾性比较分析。比较了 ORA 最低的 7180 只眼（第一三分位数：0.35 ± 0.13 屈光度 [D]）和 ORA 最高的 7208 只眼（最后三分位数：1.13 ± 0.25 D）的标准结果。
ORA 呈右偏态正态分布（R = 0.99），平均值±标准差为 0.73 ± 0.36 D。低 ORA 眼与高 ORA 眼的有效性指数相同（0.98 ± 0.07 与 0.98 ± 0.08；P =.99），具有相同百分比的等效球镜值在目标值的±0.50 D 以内（94.7% 与 94.1%；P =.11）。安全性指数（1.00 ± 0.04 与 1.00 ± 0.04；P =.99）和 Alpins 校正指数（1.01 ± 0.37 与 1.00 ± 0.43；P =.10）相同。与低 ORA 眼相比，高 ORA 眼术后残余散光为 0.75 D 或更大的比例更高（6.1% 与 3.9%）。ORA ⩾ 1.50 D（人群的 2.5%）的高度 ORA 眼，其有效性指数从 0.98 略微降低至 0.97（P <.001）。
在大多数初次接受 LASIK 手术的患者中，ORA 对基于地形图的临床结果的贡献可以忽略不计，低 ORA 和高 ORA 组均具有良好的有效性、准确性和安全性。对于在眼前部屈光度上进行治疗的高度 ORA 近视眼，不应排除在基于地形图的 LASIK 之外。
