Wei P H, Wang Y, Li H, Dou R, Li L Y, Zhao W, Zhang J M
Tianjin Medical University, Clinical College of Ophthalmology, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin 300020, China.
Zhonghua Yan Ke Za Zhi. 2017 Mar 11;53(3):182-187. doi: 10.3760/cma.j.issn.0412-4081.2017.03.007.
To investigate the effect of optical zone diameter on corneal biomechanical properties after small incision lenticule extraction (SMILE). In this prospective case-control study, 62 eyes of 42 patients with myopia and myopic astigmatism that had undergone SMILE procedure were divided into 2 groups according to the optical zone (OZ) diameter: group A, 31 eyes of 19 patients, OZ 6.5 mm; group B, 31eyes of 23 patients, OZ6.0 mm. These patients were examined for corneal hysteresis (CH) and corneal resistance factor (CRF) with the Ocular Response Analyzer (ORA) preoperatively and at 1 week, 1 month and 3 months postoperatively; at the same time, the central corneal thickness-corrected indices of DifCH and DifCRF were calculated. Pearson correlation was applied to analyze the correlation between CH and CRF and central corneal thickness. Independent-samples t test was utilized to compare CH and CRF between the two groups. Repeated ANOVA was used to compare the difference of corneal biomechanical properties at different follow-up timepoints. The preoperative mean CRF and CH values were (10.13±1.19) mmHg and (9.65±1.12) mmHg in group A and (10.34±0.89) mmHg and (10.04± 1.05) mmHg in group B, respectively, and no significant differences were found in CRF and CH between the two groups (CRF: -0.807, 0.423. CH: -1.405, 0.165). The mean CRF values in group A at postoperative 1 week and 3 months were (6.62 ± 1.09) mmHg and (6.83 ± 1.07) mmHg, respectively, which were significantly lower than the relevant mean CRF values in group B (-2.703, 0.009. -3.733, 0.001). Meanwhile, the mean CH values at 1 week, 1 month and 3 months postoperatively in group A were (7.31±1.06) mmHg, (7.37±0.96) mmHg and (7.82±0.97) mmHg, respectively, which were significantly lower than those in group B (-2.415, 0.019. -2.113, 0.039. -2.67, 0.01). Moreover, the DifCRF and DifCH values in group A were significantly lower than those in group B at 3 months postoperatively (-3.409, 0.001. -2.064, 0.044). The CRF and CH values in both groups showed a significant reduction at 1 week, 1 month and 3 months postoperatively (0.05). The size of optical zone has some effects on corneal biomechanical properties after SMILE. The smaller optical zone diameter has a relatively smaller effect. .
探讨小切口透镜切除术（SMILE）后光学区直径对角膜生物力学性能的影响。在这项前瞻性病例对照研究中，42例近视和近视散光患者的62只眼接受了SMILE手术，根据光学区（OZ）直径分为2组：A组，19例患者的31只眼，OZ为6.5mm；B组，23例患者的31只眼，OZ为6.0mm。术前及术后1周、1个月和3个月使用眼反应分析仪（ORA）对这些患者进行角膜滞后（CH）和角膜阻力因子（CRF）检查；同时，计算经中央角膜厚度校正的DifCH和DifCRF指数。采用Pearson相关性分析CH与CRF及中央角膜厚度之间的相关性。采用独立样本t检验比较两组之间的CH和CRF。采用重复方差分析比较不同随访时间点角膜生物力学性能的差异。A组术前平均CRF和CH值分别为（10.13±1.19）mmHg和（9.65±1.12）mmHg，B组分别为（10.34±0.89）mmHg和（10.04±1.05）mmHg，两组之间的CRF和CH无显著差异（CRF：-0.807，P = 0.423；CH：-1.405，P = 0.165）。A组术后1周和3个月的平均CRF值分别为（6.62±1.09）mmHg和（6.83±1.07）mmHg，显著低于B组相应的平均CRF值（分别为-2.703，P = 0.009；-3.733，P = 0.001）。同时，A组术后1周、1个月和3个月的平均CH值分别为（7.31±1.06）mmHg、（7.37±0.96）mmHg和（7.82±0.97）mmHg，显著低于B组（分别为-2.415，P = 0.019；-2.113，P = 0.039；-2.67，P = 0.01）。此外，术后3个月A组的DifCRF和DifCH值显著低于B组（分别为-3.409，P = 0.001；-2.064，P = 0.044）。两组的CRF和CH值在术后1周、1个月和3个月均显著降低（P < 0.05）。光学区大小对SMILE术后角膜生物力学性能有一定影响。光学区直径越小，影响相对越小。
