Nabil Karim Mahmoud
Department of Ophthalmology, Faculty of Medicine, University of Alexandria, 19 Amin Fekry Street, Raml station, Alexandria, 21523, Egypt.
Int Ophthalmol. 2019 Aug;39(8):1803-1808. doi: 10.1007/s10792-018-1007-y. Epub 2018 Aug 23.
The purpose of this retrospective study was to assess the accuracy of minus power intraocular lens calculation using partial coherence interferometry and OKULIX ray tracing software.
We included 25 consecutive, myopic eyes with axial length ≥ 30 mm (25 patients, 13 males and 12 females, and 57.6 ± 10.3 years old), which underwent phacoemulsification and implantation of a minus power intraocular lens in the capsular bag. Axial length measurement and corneal topography were performed using the OA-1000 optical biometer and Topographic Modeling System TMS-5, respectively. The IOL power was calculated using SRK/T formula and OKULIX ray tracing software. The implanted IOL power was chosen based on OKULIX ray tracing software calculation aiming for - 2 diopters (D) of myopia.
SRK/T calculated IOL power (- 6.3 ± 2.8 D) showed statistically significant difference compared to OKULIX calculated IOL power (- 4.7 ± 2.6 D), r 0.994 p < 0.001. The expected refraction with implanted IOL was - 1.7 ± 0.9 D based on OKULIX ray tracing software calculation. A statistically significant difference was reported between implanted IOL and OKULIX calculated IOL power (2.7 ± 1.4 D), r 0.981 p < 0.001. A statistically significant difference was reported between the expected refraction with implanted IOL and the achieved spherical refraction at 1 month postoperatively (1.4 ± 0.7 D), r 0.77 p < 0.001. The achieved spherical refraction at 1 month postoperatively was 0.2 ± 0.2 D.
Although OKULIX ray tracing software yielded more accurate minus power intraocular lens calculation in extreme myopia, compared to SRK/T formula, yet it still shows tendency toward hyperopia.
本回顾性研究的目的是评估使用部分相干干涉测量法和OKULIX光线追踪软件计算负屈光度人工晶状体的准确性。
我们纳入了25只连续的近视眼睛，眼轴长度≥30mm（25例患者，13例男性和12例女性，年龄57.6±10.3岁），这些眼睛接受了白内障超声乳化吸除术并在囊袋内植入了负屈光度人工晶状体。分别使用OA - 1000光学生物测量仪和地形建模系统TMS - 5进行眼轴长度测量和角膜地形图检查。使用SRK/T公式和OKULIX光线追踪软件计算人工晶状体的屈光度。根据OKULIX光线追踪软件计算结果选择植入的人工晶状体屈光度，目标是达到-2屈光度（D）的近视。
SRK/T公式计算的人工晶状体屈光度（-6.3±2.8D）与OKULIX软件计算的人工晶状体屈光度（-4.7±2.6D）相比，差异有统计学意义，r = 0.994，p < 0.001。根据OKULIX光线追踪软件计算，植入人工晶状体后的预期屈光度为-1.7±0.9D。植入的人工晶状体与OKULIX软件计算的人工晶状体屈光度之间差异有统计学意义（2.7±1.4D），r = 0.981，p < 0.001。植入人工晶状体后的预期屈光度与术后1个月实际获得的球镜屈光度之间差异有统计学意义（1.4±0.7D），r = 0.77，p < 0.001。术后1个月实际获得的球镜屈光度为0.2±0.2D。
虽然与SRK/T公式相比，OKULIX光线追踪软件在极端近视中计算负屈光度人工晶状体时更准确，但仍显示出远视倾向。
