Purpose: 

The aim of this study was to evaluate and compare early corneal biomechanical changes after small-incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK).

Methods: 

The study comprised 74 patients eligible for refractive surgery, equally allocated to PRK (37 patients) and SMILE (37 patients). Corneal biomechanical properties were recorded and compared between the 2 groups at preoperatively and 3 months after surgery using a dynamic ultra-high-speed Scheimpflug camera equipped with a noncontact tonometer.

Results: 

Both procedures significantly affected corneal biomechanical properties at 3 months after surgery. Patients in the PRK group showed significantly better results for deformation amplitude ratio (DA ratio) (P = 0.03), maximum inverse radius (InvRadMax) (P = 0.02), and A2 time (P = 0.03). The mean changes in DA ratio, HC radius, InvRadMax, and Ambrosio relational thickness were significantly higher in the SMILE group in comparison with those of the PRK group (all, P < 0.05). In both groups, change in CCT was significantly correlated with changes in DA ratio and InvRadMax (P < 0.05).

Conclusions:s 

Both SMILE and PRK refractive surgeries significantly altered corneal biomechanical properties but the changes were more prominent after SMILE.

中文翻译：

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使用非接触式眼压计进行小切口晶状体摘除和屈光性角膜切除术后角膜生物力学特性的变化

目的： 

本研究的目的是评估和比较小切口角膜基质透镜摘除术（SMILE）和屈光性角膜切除术（PRK）后早期角膜生物力学的变化。

方法： 

该研究包括 74 名符合屈光手术资格的患者，平均分配至 PRK（37 名患者）和 SMILE（37 名患者）。使用配备非接触式眼压计的动态超高速 Scheimpflug 相机记录并比较两组术前和术后 3 个月的角膜生物力学特性。

结果： 

两种手术均显着影响术后 3 个月的角膜生物力学特性。PRK组患者在变形幅度比（DA比）（P =0.03）、最大反半径（InvRadMax）（P =0.02）和A2时间（P =0.03）方面表现出明显更好的结果。与 PRK 组相比，SMILE 组 DA 比率、HC 半径、InvRadMax 和 Ambrosio 相关厚度的平均变化显着较高（均P < 0.05）。在两组中，CCT 的变化与 DA 比率和 InvRadMax 的变化显着相关（P < 0.05）。

结论： 

SMILE 和 PRK 屈光手术均显着改变了角膜生物力学特性，但 SMILE 后变化更为显着。