2mm微切口SMILE术后近视矫治眼高阶像差的变化

摘要

背景 飞秒激光小切口基质内透镜取出术(SMILE)已逐渐应用于临床,但术中切口大小不统一,2 mm微切口SMILE对术眼术后屈光度及像差的影响尚不清楚. 目的 研究2 mm微切口SMILE术后术眼屈光度和高阶像差(HOA)的变化,探讨术眼术前屈光度对术后HOA可能的影响.方法 采用系列病例观察的研究方法,选取2013年1-4月在天津市眼科医院行2 mm微切口SMILE的近视及近视散光患者31例55眼,测量患者术前及术后1周、1个月、6个月的裸眼视力(UCVA)、最佳矫正视力(BCVA)和球镜及柱镜度,评价SMILE的有效性、安全性、稳定性及可预测性,应用WaveScan波阵面像差仪测量术前及术后各时间点的HOA.采用重复测量单因素方差分析比较术前和术后各时间点的各HOA,不同时间点间两两比较采用LSD-t检验,采用Spearman秩相关分析评价术前球镜及柱镜度与术后各阶像差及总像差间的相关关系.结果 术后1周、1个月和6个月的有效性指数均为1.2,安全性指数分别为1.2、1.2和1.5.术后3个时间点的等效球镜度(SE)均为0.00D.术后1个月和6个月,分别有96.4％和97.8％的术眼达到预计矫治SE的±0.5 D以内,所有术眼均达到±1.0D以内.术后各时间点术眼垂直彗差(Z7)和球差(Z12)较术前均明显增大,差异均有统计学意义(Z7:t=9.668、10.607、9.772,均P＜0.001;Z12:t=-6.227、-6.923、-7.441,均P＜0.001),但术后3个时间点之间Z7和Z12的差异均无统计学意义(均P＞0.05).术眼术后各时间点3～6阶像差和总HOA较术前均明显增大,差异均有统计学意义(均P＜0.05),而术后3个时间点间各阶像差的差异均无统计学意义(均P＞0.05).术眼术后各时间点S3、S4、HOA与术前球镜度均呈正相关(均P＜0.05),与术前柱镜度均呈负相关(均P＜0.05).术后各时间点术眼Z7与术前球镜度呈负相关,与术前柱镜度呈正相关;Z12与术前球镜度呈正相关,而与术前柱镜度呈负相关(均P＜0.05). 结论 2 mm微切口SMILE矫治近视及近视散光安全、有效,手术稳定性好,可预测性高,虽然术后Z7和Z12、各阶像差、总HOA均较术前增大,但术后不同时间点之间的HOA相对稳定,且与术前球镜及柱镜度存在相关关系.%Background Small incision lenticule extraction (SMILE) is increasingly used for myopia.However,the size of the incision varied in different operators.The influence of 2 mm micro-incision SMILE on postoperative diopter and aberrations is not clear yet.Objective The aim of the current study was to perform a clinical analysis of the efficacy,safety,stability and predictability of 2 mm micro-incision SMILE and investigate the influence of preoperative sphere and cylinder power on postoperative aberrations.Methods A serial cases observational study was carried out under the approval of Ethic Committee of Tianjin Eye Hospital and informed consent of each patient.Fifty-five eyes of 31 subjects with myopia and myopic astigmatism were enrolled in this study in Tianjin Eye Hospital from January to April 2013 and a 2 mm micro-incision SMILE was performed on the eyes.Follow-up visits were performed at 1 week,1 month and 6 months after operation.Uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),manifest and cycloplegic refraction were examined at each postoperative time points to evaluate the efficacy,safety,stability and predictability of 2 mm micro-incision SMILE.Wave-front aberrations were measured by WaveScan aberrometer.Repeated measurement analysis of variance was used for the comparison of the differences of aberrations before and after the surgery.And the differences between various follow-up visits were compared with LSD-t test.The relationship between preoperative sphere or cylinder power and aberrations postoperatively were analyzed by Spearman rank correlation.Results At 1 week,1 month and 6 months postoperatively,the effective index was 1.2,and the safety indexes were 1.2,1.2 and 1.5 respectively.The spherical equivalent remained 0.00 D at each postoperative time point.And 96.4％ and 97.8％ of eyes were within ±0.5 D of intend correction and 100％ were within ± 1.0 D of the intend correction at 1 month and 6 months postoperatively.Vertical coma (Z7) and spherical aberration (Z12) were significantly raised at 1 week,1 month and 6 months after surgery compared with the values preoperatively (Z7:t =9.668,10.607,9.772,all at P ＜ 0.001 ;Z 12:t =-6.227,-6.923,-7.441,all at P＜0.001).The Zernike coefficients were relatively symmetrical between various time points postoperatively (all at P＞0.05).Third-order to sixth-order aberrations and higher order abberration (HOA) showed significant increase at various time points after the surgery compared with the values before surgery (all at P＜0.05),and no significant differences were seen between various follow-up visits (all at P＞0.05).Positive correlations were found between preoperative sphere and S3,S4 and HOA at 1 week,1 month and 6 months postoperatively (P＜0.05).Negative correlations were found between preoperative cylinder and S3,S4 and HOA at postoperatively various time points (all at P＜0.05).In addition,significant positive correlations were seen between Z7 and preoperative cylinder as well as between Z12 and sphere preoperatively,and negative correlations also were observed between Z7 and preoperative sphere as well as between Z12 and cylinder preoperatively at each follow-up visits(all at P＜0.05).Conclusions SMILE with 2 mm micro-incision is a safe,effective,stable and predictable procedure for myopic and myopic astigmatism eyes.The aberrations and Zernike terms remain stable after surgery until 6 months although these parameters present elevation to a certain extent.Preoperative SE and astigmatism power affect postoperative aberrations.