IRCCS Fondazione Bietti, Rome, Italy.
Eye Clinic, Department of Neurosciences, and Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy.
J Cataract Refract Surg. 2019 May;45(5):576-581. doi: 10.1016/j.jcrs.2018.11.029. Epub 2019 Feb 21.
To assess the refractive accuracy of different formulas for intraocular lens (IOL) power calculation in eyes with keratoconus.
IRCCS Fondazione Bietti, Rome, Italy.
Multicenter retrospective interventional study.
A consecutive series of eyes with keratoconus that had cataract surgery were evaluated. Keratometry, anterior chamber depth, and axial length were measured preoperatively with optical biometry; IOL power was calculated with the Barrett Universal II, Haigis, Hoffer Q, Holladay 1, and SRK/T formulas. Subjective refraction was assessed at 1 month. The mean prediction error (PE), median absolute error (MedAE) and percentage of eyes with a PE within ±0.50 diopters (D), ±0.75 D, and ±1.00 D were calculated.
The final spherical equivalent was -0.52 D ±1.61 (SD). In the whole sample (41 eyes), the mean PE was positive (hyperopic surprise) with all formulas; the lowest PE (0.91 D) and MedAE (0.62 D) were obtained with the SRK/T formula. In stage I eyes (n = 21), the MedAE ranged between 0.43 and 0.91 D; the SRK/T formula achieved the lowest MedAE and the highest rate of eyes with a PE within ±0.50 (61.9%). In stage II eyes (n = 13), the MedAE ranged between 0.75 D and 1.50 D; the SRK/T formula achieved the lowest MedAE and the highest rate of eyes with a PE within ±0.50 (30.8%). In stage III eyes (n = 7), the MedAE was higher than 2.50 D with all formulas.
In keratoconus eyes, all formulas led to a hyperopic refractive outcome. The SRK/T was the most accurate formula. The results were worse in advanced stages of the disease.
评估不同公式在计算圆锥角膜眼人工晶状体（IOL）屈光力时的准确性。
意大利罗马 Bietti 基金会 IRCCS。
多中心回顾性干预研究。
评估了一系列连续患有圆锥角膜且接受白内障手术的患者。在术前使用光学生物测量仪测量角膜曲率、前房深度和眼轴长度；使用 Barrett Universal II、Haigis、Hoffer Q、Holladay 1 和 SRK/T 公式计算 IOL 屈光力。在术后 1 个月评估主观屈光度。计算平均预测误差（PE）、中位数绝对误差（MedAE）以及预测误差在±0.50 屈光度（D）、±0.75 D 和±1.00 D 范围内的眼的百分比。
最终的等效球镜为-0.52 D ±1.61（SD）。在整个样本（41 只眼）中，所有公式的平均 PE 均为正（远视惊喜）；SRK/T 公式的 PE 最低（0.91 D），MedAE 最低（0.62 D）。在 I 期眼（n = 21）中，MedAE 范围在 0.43 至 0.91 D 之间；SRK/T 公式的 MedAE 最低，预测误差在±0.50 范围内的眼的比例最高（61.9%）。在 II 期眼（n = 13）中，MedAE 范围在 0.75 D 和 1.50 D 之间；SRK/T 公式的 MedAE 最低，预测误差在±0.50 范围内的眼的比例最高（30.8%）。在 III 期眼（n = 7）中，所有公式的 MedAE 均高于 2.50 D。
在圆锥角膜眼中，所有公式均导致远视屈光结果。SRK/T 是最准确的公式。在疾病的晚期，结果更差。
