Shetty Rohit, Francis Mathew, Shroff Rushad, Pahuja Natasha, Khamar Pooja, Girrish Molleti, Nuijts Rudy M M A, Sinha Roy Abhijit
Cornea and Refractive Surgery Division, Narayana Nethralaya, Bommansandra, Bangalore, India.
Imaging, Biomechanics and Mathematical Modeling Solutions (IBMS) Lab, Narayana Nethralaya Foundation, Bangalore, India.
Invest Ophthalmol Vis Sci. 2017 Nov 1;58(13):5703-5712. doi: 10.1167/iovs.17-22864.
To evaluate transient corneal tissue healing and biomechanical changes between laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE) eyes.
In each patient, one eye underwent LASIK and the other underwent SMILE. Optical coherence tomography (OCT) and dynamic Scheimpflug imaging (Corvis-ST) was used to assess tissue healing and biomechanics, respectively. Analyses of OCT scans yielded corneal speckle distribution (CSD) and Bowman's roughness index (BRI). Waveform analyses of deformation amplitude yielded corneal stiffness. Further, corneal force versus corneal deformation data helped compare the two procedures.
BRI increased and then decreased transiently after both treatments (P < 0.05). However, SMILE eyes had BRI similar to that of their preoperative state compared to LASIK eyes at 6-month follow-up. CSD indicated a marked increase in the number of bright pixels and a decrease in the number of dark pixels after SMILE (1-month follow-up) and LASIK eyes (3-month follow-up), respectively. CSD returned to near preoperative state thereafter, respectively. Corneal stiffness change from preoperative state was similar between LASIK and SMILE eyes. However, deformation at discrete values of corneal force indicated some recovery of biomechanical strength after SMILE, but not in LASIK eyes.
BRI and CSD indicated earlier tissue healing in SMILE eyes than in LASIK. CSD results may indicate delayed cell death in LASIK eyes and increased light scatter due to interface fluid in SMILE eyes. Corneal biomechanical strength remodeled better in SMILE. This may indicate some hydration-related recovery.
评估准分子原位角膜磨镶术（LASIK）和小切口基质透镜切除术（SMILE）术后角膜组织的瞬时愈合情况及生物力学变化。
每位患者的一只眼睛接受LASIK手术，另一只眼睛接受SMILE手术。分别使用光学相干断层扫描（OCT）和动态Scheimpflug成像（Corvis-ST）来评估组织愈合情况和生物力学。对OCT扫描进行分析可得出角膜散斑分布（CSD）和鲍曼层粗糙度指数（BRI）。对变形幅度进行波形分析可得出角膜硬度。此外，角膜力与角膜变形数据有助于比较这两种手术。
两种治疗后BRI均先升高后短暂下降（P < 0.05）。然而，在6个月随访时，与LASIK眼相比，SMILE眼的BRI与术前状态相似。CSD显示，SMILE眼（1个月随访）和LASIK眼（3个月随访）术后，明亮像素数量显著增加，暗像素数量减少。此后，CSD分别恢复到接近术前状态。LASIK眼和SMILE眼从术前状态开始的角膜硬度变化相似。然而，在离散的角膜力值下的变形表明，SMILE术后生物力学强度有所恢复，而LASIK眼则没有。
BRI和CSD表明，SMILE眼的组织愈合比LASIK眼更早。CSD结果可能表明LASIK眼的细胞死亡延迟，以及SMILE眼因界面液导致光散射增加。SMILE术后角膜生物力学强度重塑更好。这可能表明存在一些与水化相关的恢复。
