Supplementary Material for: Comparison of Aphakic Refraction and Biometry-Based Formulae for Secondary In-The-Bag and Sulcus-Implanted Intraocular Lens Power Estimation in Children

<b><i>Purpose:</i></b> The aim of the study was to compare the accuracy of refractive outcomes in children undergoing secondary in-the-bag or cilliary sulcus intraocular lens (IOL) implantation, using aphakic refraction (AR)-based formulae (Hug and Khan) and biometry-based formulae (Holladay 1, Hoffer Q, SRK/T, and SRK II). <b><i>Methods:</i></b> In this retrospective study, a total of 65 eyes of 44 patients who underwent secondary in-the-bag or cilliary sulcus IOL implantation were included and divided into 2 groups: 39 eyes of the in-the-bag IOL group and the other 26 eyes of the sulcus-implanted IOL group. Holladay 1, Hoffer Q, SRK/T, and SRK II formulae were employed depending on the biometric data, while Hug and Khan formulae were used based on preoperative AR. The prediction error (PE) and the absolute value of predicted error (APE) were compared between the 2 groups and formulae. <b><i>Results:</i></b> In the in-the-bag IOL group, nonsignificant differences of APE were found among the 6 formulae, while the Holladay 1, Hoffer Q, SRK/T, and SRK II all demonstrated a significant hyperopic shift of median PE value compared to the Hug formula (<i>p</i> &lt; 0.05, all), and Holladay 1 and SRK II also showed a significant hyperopic shift of PE compared to the Khan formula (<i>p</i> &lt; 0.05, both). Higher percentages of eyes with PE &lt;1 D were found using Hoffer Q and SRK/T. In the sulcus-implanted group, the Holladay 1, Hoffer Q, and SRK/T had a significantly smaller median value of APE than the Hug and Khan formulae (<i>p</i> &lt; 0.05, all), and the SRK II had a significantly smaller median value of APE than the Hug formula (<i>p</i> &lt; 0.05), while Holladay 1 had the lowest value of APE. Higher percentages of eyes within PE &lt;1 D were found using Holladay 1, Hoffer Q, and SRK/T, while the highest one was SRK/T. Significantly larger hyperopic shifts of median PE value using all the 6 formulae were found in eyes with sulcus-implanted IOL than eyes with in-the-bag implanted IOL (<i>p</i> &lt; 0.05, all). In the eyes of with in-the-bag implanted IOL, the Hug and Khan formulae had significantly smaller APE values when compared with the eyes with sulcus-implanted IOL (<i>p</i> &lt; 0.05, both). <b><i>Conclusions:</i></b> Whether IOL was in the bag or implanted in the sulcus, almost all the formulae showed hyperopic shift, SRK/T showed the best accuracy. Biometry-based formulae were superior to AR-based formulae in accuracy of IOL power calculation, especially when IOL was implanted in the sulcus. In-the-bag IOL implantation should always be with higher priorities, especially when using AR-based formulae in IOL power calculation.

**研究目的**：本研究旨在对比接受二期囊袋内或睫状沟内人工晶状体（intraocular lens, IOL）植入术的儿童的屈光结局准确性，分别采用基于无晶状体屈光（aphakic refraction, AR）的计算公式（Hug与Khan公式）以及基于生物测量学的计算公式（Holladay 1、Hoffer Q、SRK/T及SRK II公式）。
**研究方法**：本研究为回顾性研究，共纳入44例患者的65只眼，均接受二期囊袋内或睫状沟内人工晶状体植入术，将其分为两组：囊袋内人工晶状体组共39只眼，睫状沟植入人工晶状体组共26只眼。根据生物测量数据选用Holladay 1、Hoffer Q、SRK/T及SRK II公式，基于术前无晶状体屈光数据选用Hug与Khan公式。比较两组间及不同计算公式间的预测误差（prediction error, PE）与预测误差绝对值（absolute value of prediction error, APE）。
**研究结果**：在囊袋内人工晶状体组中，6种计算公式的APE无显著差异；但与Hug公式相比，Holladay 1、Hoffer Q、SRK/T及SRK II公式的中位PE均表现出显著的远视偏移（所有*p*<0.05）；与Khan公式相比，Holladay 1与SRK II公式同样表现出显著的远视偏移（均*p*<0.05）。采用Hoffer Q与SRK/T公式时，PE<1屈光度（D）的患眼占比更高。在睫状沟植入人工晶状体组中，Holladay 1、Hoffer Q及SRK/T公式的APE中位数显著低于Hug与Khan公式（所有*p*<0.05）；SRK II公式的APE中位数显著低于Hug公式（*p*<0.05），其中Holladay 1公式的APE最低。采用Holladay 1、Hoffer Q及SRK/T公式时，PE<1 D的患眼占比更高，其中SRK/T公式占比最高。与囊袋内植入人工晶状体的患眼相比，睫状沟植入人工晶状体的患眼使用6种计算公式的中位PE均表现出显著更大的远视偏移（所有*p*<0.05）。在囊袋内植入人工晶状体的患眼中，使用Hug与Khan公式时的APE显著低于睫状沟植入人工晶状体的患眼（均*p*<0.05）。
**研究结论**：无论人工晶状体植入于囊袋内还是睫状沟内，几乎所有计算公式均表现出远视偏移；SRK/T公式的计算准确性最优。基于生物测量学的人工晶状体屈光度计算公式的准确性优于基于AR的计算公式，在人工晶状体植入于睫状沟内时这一优势尤为显著。临床应优先选择囊袋内人工晶状体植入术，在采用基于AR的计算公式进行人工晶状体屈光度计算时尤其如此。