Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, North Dongxia Road, Shantou, 515041, Guangdong, China.
Shantou University Medical College, Shantou, Guangdong, China.
Int Ophthalmol. 2022 Oct;42(10):3211-3219. doi: 10.1007/s10792-022-02322-5. Epub 2022 Sep 3.
Hyperopic surprises tend to occur in axial myopic eyes and other factors including corneal curvature have rarely been analyzed in cataract surgery, especially in eyes with long axial length (≥ 26.0 mm). Thus, the purpose of our study was to evaluate the influence of keratometry on four different formulas (SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for long eyes.
Retrospective case series. A total of 180 eyes with axial length (AL) ≥ 26.0 mm were divided into 3 keratometry (K) groups: K ≤ 42.0 D (Flat), K ≥ 46.0 D (Steep), 42.0 < K < 46.0 D (Average), and all the eyes were underwent phacoemulsification cataract surgery with Rayner (Hove, UK) 920H IOL implantation. Prediction errors (PE) were compared between different formulas to assess the accuracy of different formulas. Multiple regression analysis was performed to investigate factors associated with the PE.
The mean absolute error was higher for all evaluated formulas in Steep group (ranging from 0.66 D to 1.02 D) than the Flat (0.34 D to 0.67 D) and Average groups (0.40 D to 0.74D). The median absolute errors predicted by Olsen formula were significantly lower than that predicted by Haigis formula (0.42 D versus 0.85 D in Steep and 0.29 D versus 0.69 D in Average) in Steep and Average groups (P = 0.012, P < 0.001, respectively). And the Olsen formula demonstrated equal accuracy to the Barrett II formula in Flat and Average groups. The predictability of the SRK/T formula was affected by the AL and K, while the predictability of Olsen and Haigis formulas was affected by the AL only.
Steep cornea has more influence on the accuracy of IOL power calculation than the other corneal shape in long eyes. Overall, both the Olsen and Barrett Universal II formulas are recommended in long eyes with unusual keratometry.
远视离焦在轴性近视眼中较为常见，而角膜曲率等其他因素在白内障手术中很少被分析，尤其是在眼轴较长（≥26.0mm）的情况下。因此，本研究旨在评估角膜曲率对四种不同公式（SRK/T、Barrett Universal II、Haigis 和 Olsen）在长眼眼人工晶状体（IOL）屈光力计算中的影响。
回顾性病例系列研究。共纳入 180 例眼轴（AL）≥26.0mm 的患者，分为 3 个角膜曲率（K）组：K≤42.0D（平）、K≥46.0D（陡）、42.0＜K＜46.0D（平均），所有患者均行白内障超声乳化吸除术联合 Rayner（英国霍夫）920H IOL 植入术。比较不同公式的预测误差（PE），以评估不同公式的准确性。进行多元回归分析以探讨与 PE 相关的因素。
陡组所有评估公式的平均绝对误差均高于平组（0.34D-0.67D）和平均组（0.40D-0.74D）（0.66D-1.02D）。Olsen 公式预测的中位数绝对误差在陡组（0.42D 与 Haigis 公式的 0.85D 相比）和平均组（0.29D 与 Haigis 公式的 0.69D 相比）均显著低于 Haigis 公式，差异有统计学意义（P=0.012，P＜0.001）。Olsen 公式在平组和平均组的准确性与 Barrett II 公式相当。SRK/T 公式的预测能力受 AL 和 K 的影响，而 Olsen 和 Haigis 公式的预测能力仅受 AL 的影响。
在长眼患者中，陡角膜对 IOL 屈光力计算的准确性影响大于其他角膜形态。总体而言，在角膜曲率异常的长眼中，推荐使用 Olsen 和 Barrett Universal II 公式。
