J Refract Surg. 2014 May;30(5):296-302. doi: 10.3928/1081597X-20140415-02.
To investigate objective optical quality and changes in light scatter after femtosecond laser small incision lenticule extraction (SMILE) for moderate to high myopia correction.
Prospective clinical study of 66 eyes of 66 patients (23 males, 43 females) with a mean age of 28.67 ± 6.62 years, mean spherical refraction of -6.06 ± 1.57 diopters, and mean cylindrical refraction of -0.68 ± 0.46 diopters. Every patient had a 3-month follow-up after a standard SMILE procedure. An optical quality analysis system was used to measure modulation transfer function cutoff frequency (MTFcutoff), Strehl2D ratio, and objective scatter index (OSI).
At 3 months postoperatively, mean spherical equivalent was 0.03 ± 0.24 diopters and corrected distance visual acuities of all patients were equal to or better than preoperative values, with a mean safety index of 1.12 ± 0.17 (range: 0.80 to 1.50) and mean efficacy index of 1.18 ± 0.21 (range: 0.80 to 1.50). Mean OSI increased from 0.75 preoperatively to 1.09 at 20 days postoperatively (P < .05), and gradually declined to 0.94 at 40 days and 0.82 at 3 months postoperatively (P > .05). MTFcutoff and Strehl2D ratio did not change significantly compared with preoperative values (P > .05). Multiple linear regression analysis revealed that preoperative OSI was significantly correlated with optical quality at 3 months. Patients with less preoperative OSI tended to acquire higher MTFcutoff (b = -8.61) and lower OSI (b = 0.65) (P < .05).
SMILE had little impact on retinal image quality after myopia correction. Postoperative OSI showed a temporary increase and then returned to normal.
研究飞秒激光小切口角膜微透镜取出术（SMILE）矫正中高度近视后客观光学质量和光散射的变化。
对 66 例（23 名男性，43 名女性）66 只眼进行前瞻性临床研究，平均年龄 28.67 ± 6.62 岁，平均球镜屈光度为-6.06 ± 1.57 屈光度，平均柱镜屈光度为-0.68 ± 0.46 屈光度。每位患者在标准 SMILE 手术后均进行 3 个月随访。采用光学质量分析系统测量调制传递函数截止频率（MTFcutoff）、Strehl2D 比和客观散射指数（OSI）。
术后 3 个月，平均等效球镜为 0.03 ± 0.24 屈光度，所有患者的矫正远视力均等于或优于术前，平均安全指数为 1.12 ± 0.17（范围：0.80 至 1.50），平均疗效指数为 1.18 ± 0.21（范围：0.80 至 1.50）。OSI 均值从术前的 0.75 增加到术后 20 天的 1.09（P<.05），然后逐渐下降到术后 40 天的 0.94 和术后 3 个月的 0.82（P>.05）。与术前值相比，MTFcutoff 和 Strehl2D 比无明显变化（P>.05）。多元线性回归分析显示，术前 OSI 与术后 3 个月的光学质量显著相关。术前 OSI 较低的患者倾向于获得更高的 MTFcutoff（b = -8.61）和更低的 OSI（b = 0.65）（P<.05）。
SMILE 矫正近视后对视网膜成像质量影响较小。术后 OSI 呈一过性升高，然后恢复正常。
