SMILE术后眼压测量值变化及预测

目的：探讨飞秒激光小切口角膜基质透镜取出术（SMILE）术后非接触式眼压计（NCT）测量值的变化，并得出一个术后眼压（IOP）的校正公式。方法：前瞻性系列病例研究。将2016 年4-12 月在盛京医院接受SMILE治疗近视和（或）散光的患者87 例（171 眼）纳入研究，测量并记录手术前后IOP、屈光度、中央角膜厚度（CCT）、角膜曲率，统计术后NCT测量值与各因素的相关性，并通过多元线性回归分析建立术后IOP的回归模型。结果：术前IOP为（13.6±3.1）mmHg（1 mmHg=0.133 kPa），术后6个月IOP为（8.7±2.1）mmHg，术后IOP NCT测量值（简称IOP测量值）较术前降低（4.9±2.5）mmHg。术后IOP测量值与术前比较差异有统计学意义（t=25.93，P < 0.001）；术后IOP测量值与术前IOP、术后CCT呈正相关（r=0.608、0.237，P < 0.01），与术前等效球镜度（SE）、最大基质透镜厚度、CCT变化率、角膜曲率变化率、手术前后平均角膜曲率变化量（△Km）、手术前后CCT变化量（△CCT）呈负相关（r=-0.190、-0.170、-0.200、-0.240、-0.250、-0.201，P < 0.05）；以术后6个月IOP测量值为因变量，各影响因素为自变量建立多元回归模型得到：术后IOP测量值=5.021+0.414×IOP术前-0.018×最大基质透镜厚度（F=57.78，P < 0.05），调整R2=0.400。结论：SMILE术后NCT所测得IOP较术前偏低。公式IOP测量值=5.021+0.414×IOP术前-0.018×最大基质透镜厚度，可以用来粗略计算SMILE术后IOP测量值，从而指导术后用药及青光眼的诊治。

Change and Prediction in Intraocular Pressure after SMILE

Objective: To evaluate the change in intraocular pressure (IOP) measured by non-contact tonometer after small incision lenticule extraction (SMILE), and to calculate a regression equation for estimating IOP. Methods: In this prospective case-series study, 87 patients (171 eyes) who underwent SMILE from April toDecember 2016 were enrolled. IOP, refractive error, central corneal thickness (CCT) and corneal curvature were measured preoperatively and postoperatively. We analyzed the relationship to different variables and calculated a correction formula for IOP after SMILE. Results: The mean IOP values were 13.6±3.1 mmHg and 8.7±2.1 mmHg before and after SMILE 6 months. Postoperative IOP decreased by 4.9±2.5 mmHg, and a t test showed that the difference was significant (t =25.93, P<0.001). Postoperative IOP was positively correlated with preoperative IOP and postoperative CCT (r =0.608, 0.237, P<0.01). Postoperative IOP was negatively correlated with preoperative spherical equivalent(SE), maximum lenticule thickness, and the rate of change rate of CCT and corneal curvature, △Km and △CCT (r =-0.190, -0.170, -0.200, -0.240, -0.250,-0.201, P<0.05). The multiple linear regression equation is IOPpos=5.021+0.414×IOPpre-0.018×maximumlenticule thickness (F=57.78, P<0.05, R2=0.400). Conclusions: Postoperative IOP is underestimated afterSMILE. The proposed correction formula may be used to predict postoperative IOP measurement.