Karabela Yunus, Eliacik Mustafa, Kocabora Mehmet Selim, Erdur Sevil Karaman, Baybora Hakan
Department of Ophthalmology, Istanbul Medipol University, Esenler Hospital, Esenler.
Department of Ophthalmology, Istanbul Medipol University, Kadıkoy Medipol Hospital, Kadıkoy.
Clin Ophthalmol. 2017 Jun 15;11:1143-1149. doi: 10.2147/OPTH.S136882. eCollection 2017.
To evaluate the accuracy of the SRK/T formula using ultrasound (US) biometry in predicting a target postoperative refraction of ±1.00D in eyes with medium axial length (AL) that underwent phacoemulsification.
The present study was a retrospective analysis, which included 538 eyes with an AL from 22.0 to 24.60 mm that underwent phacoemulsification and foldable intraocular lens (IOL) implantation (six different IOLs) in the bag. Preoperative AL was measured by US biometry and IOL power (IOLp) was calculated with the SRK/T formula. Patients had a complete ophthalmic examination, preoperatively and 1, 7, and 30 days after surgery. The achieved spherical equivalent (SE) and the prediction error (PE) were calculated. The prediction error was defined as the difference between attempted predicted target refraction and the achieved postoperative SE refraction. Statistical analysis was performed with SPSS V21.
The mean age of the patients was 66.96±9.67 years, the mean AL was 23.29±0.62 mm, the mean K1 was 43.62±1.49D, the mean K2 was 43.69±1.53D, the mean IOL power was 21.066±1.464D, the mean attempted (predicted) SE was -0.178±0.266D, and the mean achieved SE was -0.252±0.562D. The mean PE (difference between predicted and achieved SE) showed a relatively hyperopic shift (mean ± standard deviation: 0.074±0.542D, ranging from -1.855 to 2.170D, =0.001). A total of 93.87% of eyes were within ±1.00D of the PE and 92.75% of eyes within ±1.00D of achieved postoperative refraction. A total of 39 eyes (7.25%) had a refractive surprise. A total of 32 of 39 eyes were more myopic than -1.00D and 7 of them were more hypermetropic than +1.00D. There was no correlation between the mean PE and IOL type, AL, K1, K2, and IOLp. There were a positive statistically significant correlation between PE and age (=0.095; =0.028) and a negative statistically significant correlation between achieved SE and AL (Spearman's =-0.125; =0.04), and age (=-0.141; =0.01).
The IOLp calculation using the SRK/T formula with US biometry may demonstrate very good postoperative refractive outcomes in medium eyes with a few refractive surprises.
评估在接受超声乳化手术的中等眼轴长度（AL）的眼中，使用超声（US）生物测量法的SRK/T公式预测目标术后屈光度±1.00D的准确性。
本研究为回顾性分析，纳入了538只AL为22.0至24.60mm的眼睛，这些眼睛接受了超声乳化和囊袋内折叠式人工晶状体（IOL）植入（六种不同的IOL）。术前通过US生物测量法测量AL，并使用SRK/T公式计算IOL度数（IOLp）。患者在术前以及术后1天、7天和30天进行了全面的眼科检查。计算获得的球镜等效度（SE）和预测误差（PE）。预测误差定义为预期预测目标屈光度与术后获得的SE屈光度之间的差值。使用SPSS V21进行统计分析。
患者的平均年龄为66.96±9.67岁，平均AL为23.29±0.62mm，平均K1为43.62±1.49D，平均K2为43.69±1.53D，平均IOL度数为21.066±1.464D，平均预期（预测）SE为-0.178±0.266D，平均获得的SE为-0.252±0.562D。平均PE（预测SE与获得SE之间的差值）显示出相对远视偏移（平均值±标准差：0.074±0.542D；范围为-1.855至2.170D；P=0.001）。93.87%的眼睛PE值在±1.00D以内，92.75%的眼睛术后获得的屈光度在±1.00D以内。共有39只眼睛（7.25%）出现屈光意外。39只眼睛中有32只近视度数超过-1.00D，其中7只远视度数超过+1.00D。平均PE与IOL类型、AL、K1、K2和IOLp之间无相关性。PE与年龄之间存在正的统计学显著相关性（P=0.095；r=0.028），获得的SE与AL之间存在负的统计学显著相关性（Spearman's r=-0.125；P=0.04），与年龄之间也存在负的统计学显著相关性（r=-0.141；P=0.01）。
使用SRK/T公式结合US生物测量法计算IOLp，在中等眼轴的眼中可能会有非常好的术后屈光结果，且屈光意外较少。
