Helaly Hany Ahmed, Ibrahim Tamer Moussa, Hassan Mohamed Sobhy, El-Mansy Mohamed Sobhy
Ophthalmology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
BMC Ophthalmol. 2025 Apr 17;25(1):219. doi: 10.1186/s12886-025-04040-9.
to study the effect of keratoconus severity on the accuracy of intraocular lens power calculation using newer keratoconus (KC) specific formulas.
This was a retrospective case series that included 99 eyes from 99 patients. The included patients were further subdivided into 3 groups according to keratoconus severity. The results of various IOL power calculation formulas were analyzed in this study. Two KC specific formulas were employed: Barrett True K KC and Kane KC. Additionally, the following formulas were utilized: Barrett Universal II (BUII), EVO 2.0, Hoffer QST, Kane, and PEARL-DGS.
The Kane KC was the only formula to show a myopic mean prediction error (- 0.76 ± 1.06 D). BUII and Barrett True K KC formulas showed the least mean and median absolute errors. The median absolute error (MedAE) for BUII and Barrett True K KC was 0.34 and 0.35 D respectively. BUII and Barrett True K KC formulas had the highest cases within ± 0.25 D of the intended refraction (42.42% and 39.39%, respectively). In severe KC eyes, the MedAE for Barrett True K KC and BUII formulas was 0.56 and 0.46 D respectively. In severe KC eyes, Barrett True K KC and BUII formulas showed the highest cases within ± 0.25 D of the intended refraction (27.27% and 27.27%, respectively).
most non KC specific IOL power calculation formulas perform in an acceptable way in mild KC eyes. In moderate and severe KC eyes, the KC specific formulas perform better than the standard formulas. Barrett True K KC formula performed better than Kane KC in moderate and severe KC eyes. BUII formula was the best performing non KC specific formula in moderate and severe KC eyes.
研究圆锥角膜严重程度对使用更新的圆锥角膜（KC）特定公式计算人工晶状体屈光力准确性的影响。
这是一项回顾性病例系列研究，纳入了99例患者的99只眼。根据圆锥角膜严重程度，将纳入的患者进一步分为3组。本研究分析了各种人工晶状体屈光力计算公式的结果。采用了两个圆锥角膜特定公式：Barrett True K KC和Kane KC。此外，还使用了以下公式：Barrett Universal II（BUII）、EVO 2.0、Hoffer QST、Kane和PEARL-DGS。
Kane KC是唯一显示近视平均预测误差（-0.76±1.06 D）的公式。BUII和Barrett True K KC公式显示的平均和中位数绝对误差最小。BUII和Barrett True K KC的中位数绝对误差（MedAE）分别为0.34 D和0.35 D。BUII和Barrett True K KC公式在预期屈光度±0.25 D范围内的病例数最多（分别为42.42%和39.39%）。在严重圆锥角膜眼中，Barrett True K KC和BUII公式的MedAE分别为0.56 D和0.46 D。在严重圆锥角膜眼中，Barrett True K KC和BUII公式在预期屈光度±0.25 D范围内的病例数最多（分别为27.27%和27.27%）。
大多数非圆锥角膜特定的人工晶状体屈光力计算公式在轻度圆锥角膜眼中的表现尚可。在中度和重度圆锥角膜眼中，圆锥角膜特定公式的表现优于标准公式。在中度和重度圆锥角膜眼中，Barrett True K KC公式的表现优于Kane KC。BUII公式是中度和重度圆锥角膜眼中表现最佳的非圆锥角膜特定公式。
