目的：基于新一代Corvis^® ST分析成人近视患者经飞秒激光小切口角膜透镜取出术(small incision corneal lens extraction，SMILE)后角膜体(corneal volumn，CV)的变化与角膜生物力学变化的相关性，进一步证明C V对于评估SMILE术后角膜生物力学特性以及预测屈光手术结果的价值。方法：采用前瞻性病例观察研究方法，纳入2021年1月至8月在佛山市第二人民医院拟行SMILE的成人近视患者72例(72眼)。为避免双眼相关性，纳入患者的一个合适眼(右眼或者左眼)，根据术前中央角膜厚度，将厚度470~<530 μm分为低角膜厚度组，530~<560 μm为中角膜厚度组 ， ≥560μm为高角膜厚度组。应用新一代 Corvis^® ST 于术前和术后3个月测量非接触生物力学校正眼压(biomechanical intraocular pressure，bIOP)、2 mm处变形幅度的比值[DA ratiomax(2 mm)，DA2ratio]、综合半径(integrated inverse concave radius，IR)、水平方向Ambr?sio相关厚度，最薄点厚度/厚度变化率(Ambrósio’s relational thickness，ARTh)、第1次压平时角膜硬度参数(stiffness parameter applanation 1，SP-A1)、Corvis生物力学指数(Corvis biomechanical index，CBI)和应力和应变参数(stress-strain index，SSI)7项角膜生物力学参数。应用Pentacam眼前节分析系统测量中央角膜厚度(central corneal thickness，CCT)和不同区域的CV(CV_3mm、CV_5mm、CV_7mm和CV_10mm)。对比SMILE术前与术后3个月的CV、角膜生物力学参数的变化，并分析角膜生物力学参数与CV的相关性。数据采用配对、独立样本t检验分析差异性；单因素方差分析不同角膜厚度组的差异性；Spearman相关性分析和偏最小二乘回归(partial least squares linear regression，PLSLR)分析相关性。结果：SMILE术后3个月，CV_3mm、CV_5mm、CV_7mm和CV_10mm均较术前显著下降(均P<0.001)；bIOP、ARTh、SP-A1和SSI较术前明显下降(P<0.05)；DA2ratio、IR和CBI较术前明显升高(P<0.05)。术前和术后3个月不同角膜厚度组的ARTh、SP-A1DA2ratio、IR和CBI差异均有统计学意义(均P<0.05)，低中角膜厚度组SSI术前后变化不大(P>0.05)。术前DA2ratio与CV_3mm、CV_5mm呈负相关，与CV_10mm呈正相关；ARTh与CV_3mm、CV_5mm呈正相关，与CV_10mm呈负相关；bIOP与CV_10mm呈正相关；IR与CV_3mm、CV_5mm呈负相关，与CV_10mm呈正相关；SP-A1与CV_3mm、CV_5mm呈正相关，与CV_10mm呈负相关；CBI与CV_3mm、CV_5mm和CV_10mm呈负相关，SSI与CV_3mm呈正相关，与CV_10mm呈负相关。SMILE术后3个月，ARTh与CV_3mm、CV_5mm呈正相关，与CV_10mm呈负相关；CBI与CV_3mm负相关、CV_10mm呈正相关(均P<0.05)。SMILE术后3个月变化量中，ARTh与CV_3mm、CV_5mm呈正相关，与CV_10mm负相关；CBI与CV_3mm呈负相关，与CV_10mm呈正相关(均P<0.05)。结论：成人SMILE术后3个月CV_3mm、CV_5mm、CV_7mm、CV_10mm、眼压和CCT较术前均显著降低；越往周边区域CV减少量越多。SMILE术后3个月的新一代Corvis^® ST角膜生物力学新型参数较术前有显著变化；不同区域CV与角膜生物力学参数存在一定的相关性，预期SMILE术后不同区域的CV可以表征术后部分角膜生物力学特性的改变，CV可能成为表征预测角膜扩张发展的参数因素。

Objective: To evaluate the changes in corneal volume (CV) and the correlation of corneal biomechanics in adult myopic patients after small incision corneal lens extraction (SMILE) based on the new generation of Corvis^® ST.This paper further demonstrates the value of CV in evaluating corneal biomechanical properties after SMILE and predicting the outcome of refractive surgery. Methods: A total of 72 cases (72 eyes) of adult myopia who were scheduled for SMILE in The Second People’s Hospital of Foshan from January to August 2021 were included in this prospective observational case study. To avoid binocular correlation, a suitable eye for each person was selected for inclusion. Based on the preoperative central corneal thickness (CCT), the cases were divided into a low corneal thickness group (470–<530 μm), a medium corneal thickness group (530–<560 μm), and a high corneal thickness group (≥560 μm). The biomechanical intraocular pressure (bIOP), DA ratiomax (2 mm) (DA2ratio), integrated inverse concave radius (IR), Ambrósio’s relational thickness (ARTh), stiffness parameter applanation 1 (SP-A1),corvis biomechanical index (CBI) and stress-strain index (SSI) were measured by Corvis^® ST. The Pentacam anterior segment analysis system was used to measure partial CV and total CV with a diameter of 3, 5, and 7 mm from the top of the cornea, with an assumed diameter of 10 mm. The changes in corneal biomechanical parameters and CV before SMILE and 3 months after SMILE were compared. The correlation between corneal biomechanical parameters and CV was studied. Data were analyzed by paired and independent sample t-tests. One-way analysis of variance (ANOVA) was used to assess the differences between the corneal thickness groups. Spearman correlation analysis and partial least squares linear regression (PLSLR) were used for correlation analyses. Results: Three months after SMILE, the CV in different areas (CV_3mm, CV_5mm, CV_7mm, and CV_10mm) were significantly lower than those before SMILE, and the differences were statistically significant (all P<0.001). The corneal biomechanical parameters bIOP, ARTh, SP-A1, and SSI were significantly decreased compared with those before the operation (P<0.05). In contrast, the DA2 ratio, IR, and CBI were significantly higher than those before the operation (P<0.05). A comparison of the corneal biomechanical parameters ARTh, SP-A1, DA2 ratio, IR, and CBI in the different corneal thickness groups before and after SMILE showed overall differences among the groups (P<0.05).However, there was no significant change in the SSI between the low and medium corneal thickness groups. The correlation of the preoperative baseline DA2ratio was negatively correlated with CV_3mm and CV_5mm, and positively correlated with CV_10mm; Conversely, ARTh was positively correlated with CV_3mm and CV_5mm, and negatively correlated with CV_10mm; BIOP was positively correlated with CV_10mm; IR was negatively correlated with CV_3mm and CV_5mm, and positively correlated with CV_10mm; SP-A1 was positively correlated with CV_3mm and CV_5mm, and negatively correlated with CV_10mm; CBI was negatively correlated with CV_3mm, CV_5mm, and CV_10mm, while SSI was positively correlated with CV_3mm and negatively correlated with CV_10mm (all P<0.05). At 3 months after SMILE, ARTh was positively correlated with CV_3mm and CV_5mm, and negatively correlated with CV_10mm; CBI was negatively correlated with CV_3mm, and positively correlated with CV_10mm (all P<0.05). Conclusion: This study demonstrated that at 3 months after SMILE, CV_3mm, CV_5mm, CV_7mm, CV_10mm, intraocular pressure, and CCT in the central and peripheral areas decreased significantly compared with to those before the operation, and the more peripheral the area, the more the CV decreased. Three months after SMILE, the new corneal biomechanical parameters of the new generation Corvis^® ST changed significantly compared to those before the operation, and there was a certain correlation between CV in different regions and corneal biomechanical parameters. It is expected that CV in different regions after SMILE can characterize some changes in corneal biomechanical properties after SMILE, and CV may become a parameter factor for characterizing and predicting the development of corneal dilatation.