【作者】 买志彬；

【导师】 张金嵩；

【作者基本信息】 郑州大学 ， 眼科学， 2010， 博士

【摘要】 第一部分FEMTO LDV飞秒激光制作LASIK角膜瓣相关因素分析目的观察LASIK术中应用FEMTO LDV飞秒激光制作角膜瓣的特点,评估影响角膜瓣厚度及直径的相关因素。方法对130人(260只眼)进行研究,其中预设角膜瓣厚度90μm组26人52只眼,预设值为110μm组104人208只眼。预计角膜瓣直径8.5mm到9.5mm。术中应用卡尺测量角膜瓣直径,与预设角膜瓣直径进行差异性分析,并与术前角膜中央最大K值、术前角膜厚度、年龄的相关性进行回归分析。术后1周使用傅立叶域光学相干断层扫描仪(OCT)测量角膜瓣的厚度,与预设角膜瓣厚度进行差异性分析,并与术前角膜中央最大K值、角膜中央厚度、年龄、眼压以及角膜瓣直径进行相关分析。结果90μm角膜瓣组平均厚度为95.12士7.65(75.50～109.50)μm, 110μm角膜瓣组平均厚度为104.81±3.09(95.75～112.50)μm。左右眼间角膜瓣厚度差异无统计学意义(t110μm.=-1.223,t90μm=-1.343,P>0.05).两组角膜瓣厚度与术中制作角膜瓣直径呈负相关(rl10μm=-0.363,r90μm=-0.434,P<0.01),与患者术前年龄,角膜厚度,角膜中央最大K值以及眼内压均无明显相关性(rl10μm=-0.160,0.054,-0.011,-0.363；r90μm=-O.024,0.074,-0.212,-O.434,a11 P>0.05).术中角膜瓣直径与术前角膜中央最大K值及角膜厚度呈正相关(p<0.001,p<0.05)。最常见并发症为角膜瓣缘出血,未影响激光消融。结论FEMTO LDV飞秒激光制作角膜瓣预测性好、并发症少,且角膜瓣厚度不受术前角膜厚度及角膜中央最大K值影响。第二部分FEMTO LDV飞秒激光和Hansatome机械角膜刀制瓣辅助LASIK术后角膜共焦显微镜下改变对比分析目的评估并对比分析FEMTO LDV飞秒激光及Hansatome机械角膜刀制瓣辅助LASIK术后角膜细胞形态。方法行FEMTO LDV飞秒激光制瓣辅助LASIK手术10人(20只眼),同期行Hansatome机械角膜刀制瓣LASIK手术9人(18只眼)。分别于术前及术后1周,1月,3月应用HRTIII共聚焦显微镜检测角膜中央及角膜瓣边缘的形态学变化,并对比两种制瓣方式术后角膜细胞形态学的异同。结果术后1周,1月,3月时裂隙灯检查所有眼均未见角膜瓣皱褶发生。两组术后浅基质细胞密度较术前均明显减少(all P<0.001)。Hansatome组术后角膜上皮厚度早期有增厚表现,3月时接近术前厚度；FEMTO LDV组上皮厚度手术前后无明显变化。所有眼均可在切削面见到高反光颗粒,其密度FEMTO LDV组术后明显少于Hansatome组(FEMTO LDV vs Hansatome,t1w=-13.505, t1m= 11.900, t3m=-14.084, all P<0.001)。两组术后1周时均观察到角膜细胞形态改变,在切削界面后见角膜细胞激活,3月时基质细胞激活减少。FEMTO LDV组术后神经纤维的再生早于Hansatome组。FEMTO LDV组术后1周时,角膜瓣的边缘清晰、整齐。术后3月时,飞秒激光组周边角膜基质高反光,并有不规则的纤维化,提示较强的创伤愈合的过程,而机械角膜刀组角膜瓣边缘基质反光较弱,呈现较轻的纤维化。结论FEMTO LDV飞秒激光制瓣术后神经纤维再生早,角膜瓣边缘瘢痕化改变明显于Hansatome机械角膜刀。第三部分飞秒激光与机械角膜刀制瓣辅助LASIK术后视觉质量对比研究目的评价FEMTO LDV飞秒激光及Hansatome机械角膜刀制瓣辅助LASIK术后有效性,预测性,安全性；对比分析对比敏感度并结合眩光测试以及波前像差的变化,评价患者的视觉质量。方法应用Technolas217z100准分子激光系统治疗近视患者98人(196只眼),接受FEMTO LDV飞秒激光制瓣92只眼(46人,等效球镜(SE)-6.88±1.65D),同期接受Hansatome微型角膜刀制瓣104只眼(52人,等效球镜(SE)-6.78±1.05D),制瓣后均行波前像差引导的准分子激光切削术。分别于术前、术后1周、1月、3月检测两组患者裸眼视力、最佳矫正视力、显然验光、对比敏感度、眩光对比敏感度以及高阶像差。结果(1)视力：术后1周,飞秒激光组的裸眼视力(UCVA)达到或高于最佳矫正视力(BSCVA)的有59/92(64.13%),机械角膜刀组有76/104(73.08%)；3月时飞秒激光组UCVA>BSCVA的有86/92(93.48%),机械角膜刀组为96/104(92.31%)。(2)屈光度：术后1周时屈光度飞秒激光组为+0.49D,角膜刀组为+0.35D；术后3月飞秒激光组屈光度为+0.16D,角膜刀组为-0.15D。(3)对比敏感度：飞秒激光组明视下对比敏感度(CS)手术前后的差异无统计学意义,暗视下对比敏感度术后1周时最低,1月时CS值已达术前。(4)眩光的影响：FEMTO LDV组明视下眩光未对CS造成明显影响。暗视下术后1周时CS受眩光影响最明显,在1.5、3.0、6.0、18.0cpd处引起CS下降(P<0.05)。术后1月及3月时眩光均未引起CS的下降。术后明视下眩光对两组患者CS的影响没有显著差异。暗视下3月时,在中低空间频率(1.5、3.0、6.0cpd) FEMTO LDV组CS值高于Hansatome组。(5)高阶像差：FEMTO LDV组总高阶像差(HOA),三阶像差及彗差的均方根值(RMS)术后1周,1月时较术前增加(p<0.05),至3月时与术前的差异无统计学意义。四阶像差及球差术后各期RMS值均高于术前,差异有统计学意义(p<0.05)。术后3月时FEMTO LDV组HOA及彗差均低于Hansatome组(P=0.045,P=0.047)。球差、三叶草两组间均差异无统计学意义(P>0.05)。结论飞秒激光辅助LASIK手术可减少术后高阶像差的增加,获得较好的视觉质量,术后CS优于机械角膜刀组,与术后两组高阶像差不同有关。更多还原

【Abstract】 PARTI Facts Relating to the Corneal Flap Creation With The FEMTO LDV Femtosecond LaserPURPOSE To present the flap characteristics and assess the facts correlating to the thickness and diameter of the cornea flap created with femtosecond laser.METHODS Two hundred sixty consecutive eyes of 130 previously non-operated patients were treated with the FEMTO LDV. Twenty-six patients had an intended flap thickness of 90μm and 104 were 110μm. Intended flap diameter varied from 8.5 to 9.5mm.The flap diameter was measured by callipers. Single variable correlation of flap diameter and preoperative keratometric value K1, corneal thickness or patient age were determined. Similarly, single variable correlations of the flap thickness (measured by optical coherence tomography,OCT) and preoperative keratometric value K1, corneal thickness, patient age, intraocular pressure. flap diameter were calculated at 1 week after surgery.RESULTS The 90μm flap group has a mean flap thickness of 95.12±7.65 (75.50～109.50)μm, while for the 110μm group the mean flap thickness was 104.81±3.09(95.75～112.50)μm. The difference between rignt and left eyes was not statistically significant (tl10μm=-1.223, t90μm=-1.343, P>0.05). Corneal flap thickness was inversely correlated with flap diameter (r110μm=-0.363, r90μm =-0.434, P<0.01), but was not dependent on preoperative patient age, corneal thickness, keratometric value K1, or intraocular pressure (r110μm=-0.160,0.054, -0.011,-0.363; r90μm=0.024,0.074,-0.212,-0.434, all P>0.05). Corneal flap diameter was positively correlated with preoperative corneal keratometric value K1 and thickness (P<0.001, P<0.05). The most common complication was minor bleeding during the procedure, but none prevented further laser ablation.CONCLUSIONS The Ziemer FEMTO LDV laser created LASIK flaps have relatively good predictability and minimal intraoperative complications. Preoperative central cornea thickness and keratometric value K1 of eye dose not affect the thickness of the corneal flap made with femtosecond laser.PARTⅡIn Vivo Corneal Confocal Microscopy Comparison of Ziemer FEMTO LDV Femtosecond Laser and Hansatome Mechanical Microkeratome for Laser In Situ KeratomileusisPURPOSE To assess and compare corneal cellular modifications induced by Ziemer FEMTO LDV femtosecond laser and mechanical microkeratome Hansatome for LASIK.METHODS In this case-control study, FEMTO LDV femtosecond laser (10 patients/20 eyes) and mechanical microkeratome Hansatome (9 patients/18 eyes) assisted flap preparation were both performed during the same period. All eyes were examined with the HRTⅢpre-surgery and 1 week,1 month,3 months post-surgery. The morphological changes at the center and margin of the flaps were observed, and difference of cellular morphology after surgery between the two approaches were evaluated.RESULTS No cornea had clinically significant flap microfolds detected by slit-lamp examination 1 week,1 month and 3 months after the surgery. Both groups showed decreased density of upper stromal cells (all P＜0.001). Hansatome group demonstrated slightly thickened corneal epithelium early after the surgery, which returned to the pre-surgery level at 3 months. FEMTO LDV group demonstrated unchanged before and after surgery.All eyes showed high reflective interface particles, and its density was lower in the FEMTO LDV group than in the Hansatome group (P<0.001). Evaluation of both groups on day 7 showed keratocyte transformation, most likely related to cellular activation beneath the interface. The activation of stromal cells was decreased at 3 months. The FEMTO LDV group showed earlier regeneration of nerve fibers than the Hansatome group. The flap margin after the femtosecond laser technique appeared microscopically as a clear-cut and regular edge 1 week after the surgery. At month 3, irregular secondary fibrosis, adjacent to the still well-defined FEMTO LDV flap edge, was observed, which indicated a stronger healing ability. In contrast, the flap margin of the mechanical microkeratome had the appearance of a less clearly identified fibrotic scar.CONCLUSIONS The FEMTO LDV flap margin showed earlier nerve fiber regeneration and greater fibrotic scarring than that induced by the mechanical microkeratome.PARTⅡComparison of Visual Quality After LASIK Flap Creation With a Femtosecond Laser and a Mechanical MicrokeratomePURPOSE To assess efficacy, predictability and safety after FEMTO LDV femtosecond laser and mechanical microkeratome hansatome LASIK for myopia, and to evaluate the patients’visual quality by comparing the contrast sensitivity(CS), CS under the glare stimulus and aberration changes.METHODS Ninety-eight myopic patients (196 eyes) were treated with LASIK using the Technolas217zl00 laser system. For flap preparation,92 eyes (46 patients, spherical equivalent [SE],-6.88±1.65D) were treated with FEMTO LDV approach, and the other 104 eyes (52 patients, SE,-6.78±1.05D) were treated with Hansatome approach.Zyoptix wavefront-guided LASIK was performed for each of these eyes after the flap preparation. For evaluation of efficacy, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, contrast sensitivity, CS under the glare stimulus and high order aberrations (HOA) were evaluated preoperatively and 1 week,1 month,3 months after treatment.RESULTS (1) Visual acuity. At 1 week after the surgery,59/92(64.13%) patients of the FEMTO LDV group had their UCVA reaching or surpassing the BSCVA, while in the Hansatome group, this rate was 76/104 (73.08%). At 3 months after the surgery, the rate of UCVA>BSCVA was 86/92(93.48%) in FEMTO LDV group and 96/104(92.31%) in Hansatome group. (2) Refraction. The refraction was +0.49D in the FEMTO LDV group and +0.35D in the Hansatome group at 1 week after surgery, while at 3 months, it was +0.16 D in the FEMTO LDV group and-0.15D in the Hansatome group. (3) Contrast sensitivity. The FEMTO LDV group photopic CS was not different before and after the surgery. The mesopic CS decreased to the lowest level at 1 week postoperation, and returned to preoperative level at 1 month after operation.(4) CS under the glare stimulus. Glare didn’t influence the photopic CS in the FEMTO LDV group. Mesopic CS was most obviously influenced by glare at 1 week but not 1 or 3 months after surgery, causing decrease of CS at 1.5,3.0,6.0 and 18.0 cpd (P<0.05). However, under photopievision, glare didn’t make difference in CS between the 2 groups after surgery. At 3 months, at medium to low spatial frequencies (1.5,3.0,6.0 cpd), the CS of FEMTO LDV group was higher than the hansatome group. (5) HOA. In the FEMTO LDV group, the root-mean-square (RMS) of CHOAs,3 order aberration and Coma were increased at 1 week and 1 month after the surgery, but returned to the preoperation level at 3 months. The RMS of 4 order aberration and spherical aberration were higher than the preoperation level at all periods after the surgery (P<0.05). At 3 months, the HOA and Coma in the FEMTO LDV group were all lower than the Hansatome group (P=0.045, P=0.047). There were no difference in spherical aberration and trefoil between the 2 groups.CONCLUSIONS Femtosecond laser for LASIK surgery greatly mitigates the increase of HOA after the surgery.Patients undergoing femtosecond laser-assisted LASIK have better quality of vision after surgery than hansatome patients. The improvements of CS after the femtosecond laser assisted LASIK surgery may be related to the differences in postoperative HOAs found with femtosecond laser and microkeratome flap creation.更多还原