SMILE术后不同瞳孔直径下视觉质量的比较

目的：探讨近视患者飞秒激光小切口角膜基质透镜取出术（SMILE）后在4 mm和7 mm瞳孔直径下视觉质量变化及其影响因素。方法：前瞻性临床研究。选取2019年2─5月在中南大学湘雅医院行 SMILE的近视和近视散光患者46例，年龄18～36岁，均选择右眼数据用于统计。采用欧卡斯视觉质量分析系统测量术眼在4 mm和7 mm瞳孔直径下术前及术后1周、1个月、3个月的调制传递函数（MTF）、调制传递函数截止频率（MTF cutoff）和斯特列尔比（SR）变化。采用主观质量问卷评估患者主观视觉质量。手术前后视力、屈光度、MTF及SR值等比较采用重复测量方差分析。多元线性回归分析SMILE术后3个月视觉质量变化的影响因素。结果：SMILE术后裸眼视力及等效球镜度 （SE）较术前明显改善（F=210.976，P<0.001；F=144.129，P<0.001）。SMILE术后3个月，有效性及安全性指数分别为0.97±0.11、1.00±0.06，SE在±0.5 D内的患者占100%。SMILE手术前后不同时间点4 mm及7 mm瞳孔直径下SR、MTF、MTF cutoff值的总体比较，差异均有统计学意义（均P<0.05）。 4 mm瞳孔直径（明视环境）下各空间频率下MTF、MTF cutoff、SR先降后升，术后１个月恢复至术前水平。7 mm瞳孔直径（暗视环境）下，MTF cutoff术后１个月恢复至术前水平，MTF、SR在术后 3个月恢复至术前水平。暗视环境下，年龄、术前暗瞳大小为SR及空间频率20、25、30 c/d MTF的影响因素（B年龄=-0.440、-0.409、-0.404、-0.389，均P<0.05；B暗瞳=-0.404、-0.333、-0.371、-0.368， 均P<0.05），年龄为MTF cutoff及空间频率5、10、15 c/d MTF的影响因素（B=-0.522，P=0.003； B=-0.403，P=0.008；B=-0.409，P=0.008；B=-0.416，P=0.004）。术前暗瞳大小为夜视力、眩光光晕得分的影响因素（B=-0.370，P=0.020；B=-0.417，P=0.013）。结论：SMILE术后早期明、暗环境下视觉质量较术前有所降低，暗环境下视觉质量与术前暗瞳大小及年龄呈负相关。

Comparative Analysis of Visual Quality with Different Pupil Diameters after Small Incision Lenticule Extraction

Objective: To evaluate the visual acuity changes and influencing factors under 4 mm and 7 mm pupil diameters after small incision lenticule extraction (SMILE). Methods: A prospective analysis wasperformed on 46 right eyes of 46 myopia or myopic astigmatism patients (age, 18-36 years) who underwent SMILE surgery in Eye Center of Xiangya Hospital, Central South University. Modulation transfer function (MTF), modulation transfer function cutoff ( MTF cutoff), and strehl ratio (SR) were measured under the 4 mm and 7 mm pupil diameters by an optical quality analysis system before surgery and 1 week and 1 and 3 months after surgery. A subjective visual quality questionnaire assessed the subjective visual quality of patients. Repeated measures analysis of variance was used for preoperative and postoperative comparison of visual acuity, diopter, MTF value, and so on. Multiple linear regression was used to explore the influencing factors of visual quality changes at 3 months after SMILE. Results: The differences in uncorrected visual acuity (UCVA) and spherical equivalent (SE) before and after SMILE surgery were statistically significant (F=210.976, P<0.001; F=144.129, P<0.001). At 3 months after surgery, the efficacy and safety indexes were 0.97±0.11 and 1.00±0.06, respectively. SE was limited within ±0.50 D in all patients. The differences of SR, MTF, and MTF cutoff values between 4 mm and 7 mm pupil diameters before and after surgery were statistically significant (all P<0.05). Under the photopic environment (4 mm pupil diameter), MTF, MTF cutoff and SR decreased initially after surgery, increased thereafter, and recovered to the preoperative levels at 1 month after surgery. Under the scotopic environment (7 mm pupil diameter), MTF and SR returned to preoperative levels at 3 month after surgery (P>0.05), while MTF cutoff returned to preoperative levels at 1 month after surgery. Under the scotopic environment, the MTF values of 20, 25 and 30 c/d spatial frequencies and SR were mainly negatively correlated with age and dark pupil diameter before surgery (Bage=-0.440, -0.409, -0.404, -0.389, all P<0.05; Bdark pupil diameter=-0.404, -0.333, -0.371, -0.368, all P<0.05). The MTF cutoff value and the MTF values of 5, 10 and 15 c/d mainly had a negative correlation with age (B=-0.522, P=0.003; B=-0.403, P=0.008; B=-0.409, P=0.008; B=-0.416, P=0.004). Night vision and glare halo scores had negative correlations with the preoperative dark pupil diameter (B=-0.370, P=0.020; B=-0.417, P=0.013). Conclusions: Visual quality decreased slightly under the photopic and scotopic environments in the early stage after SMILE. The visual quality under the scotopic environment was negatively correlated with preoperative dark diameter and age.