School of Medicine, Department of Ophthalmology and the Kittner Eye Center, University of North Carolina at Chapel Hill, Chapel Hill, NC.
Cornea. 2024 Aug 1;43(8):999-1007. doi: 10.1097/ICO.0000000000003482. Epub 2024 Jan 30.
The aim of this study was to evaluate outcomes using total corneal astigmatism (TCA) to calculate arcuate keratotomy(ies) (AK) parameters performed with femtosecond laser-assisted cataract surgery to reduce low corneal astigmatism.
Patients who had femtosecond laser-assisted cataract surgery and AK with 0.50 diopter (D) to 1.30 D of TCA were included. Exclusion criteria were intraoperative complications, preexisting corneal surgery, and comorbidities that might adversely affect outcomes. Corneal tomography (Galilei G4, Zeimer Ophthalmic Systems AG) was performed preoperatively and 1 month postoperatively. TCA was input into the Donnenfeld limbal relaxing incisions nomogram to calculate the AK parameters. Preoperative and postoperative tomographic and subjective refractive measurements were compared. The Alpins method for vector analysis evaluated results.
Eighty-two eyes of 82 patients were included. Mean preoperative TCA was significantly reduced from 0.80 ± 0.19 D to 0.51 D ± 0.26 D ( P < 0.001). Preoperative posterior corneal astigmatism, -0.28 ± 0.13 D, was unchanged, postoperative posterior corneal astigmatism, -0.28 ± 0.14 D ( P = 0.653). Target-induced astigmatism arithmetic mean (0.82 ± 0.21 D) was greater than that of the surgically induced astigmatism (0.70 ± 0.40 D), resulting in an arithmetic mean difference vector of 0.51 ± 0.27 D with a summated mean at 0.16 D at 20 degrees. The correction index was 0.87, indicating undercorrection. Angle of error arithmetic mean, -1.27 ± 23.27 degrees, indicated good alignment.
Inputting TCA for calculation of femtosecond laser AK parameters can reduce low amounts of preoperative corneal astigmatism, thereby improving uncorrected vision.
本研究旨在评估使用飞秒激光辅助白内障手术计算总角膜散光（TCA）以降低低角膜散光的弧形角膜切开术（AK）参数的结果。
纳入接受飞秒激光辅助白内障手术和 TCA 为 0.50 屈光度（D）至 1.30 D 的 AK 的患者。排除标准为术中并发症、预先存在的角膜手术和可能对结果产生不利影响的合并症。术前和术后 1 个月行角膜断层扫描（Galilei G4，Zeimer Ophthalmic Systems AG）。将 TCA 输入 Donnenfeld 缘松解切口诺模图以计算 AK 参数。比较术前和术后的断层扫描和主观屈光测量值。Alpins 方法进行向量分析评估结果。
82 例患者的 82 只眼被纳入研究。平均术前 TCA 从 0.80 ± 0.19 D 显著降低至 0.51 ± 0.26 D（P < 0.001）。术前后角膜散光分别为-0.28 ± 0.13 D 和-0.28 ± 0.14 D（P = 0.653）。目标诱导散光的平均值（0.82 ± 0.21 D）大于手术诱导散光（0.70 ± 0.40 D），导致平均差向量为 0.51 ± 0.27 D，总和平均为 0.16 D，在 20 度时有 51 度的矢量角。校正指数为 0.87，表明存在欠矫。误差角平均值为-1.27 ± 23.27 度，表明对准良好。
输入 TCA 以计算飞秒激光 AK 参数可降低低术前角膜散光量，从而提高未矫正视力。
