Dry eye and corneal sensitivity after small incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis:a Meta-analysis

AIM：To assess the corneal sensitivity and the incidences of dry eye after small incision lenticule extraction（SMILE） and femtosecond laser-assisted in situ keratomileusis（FSLASIK）.METHODS：The Meta-analysis was performed using Rev Man 5.3.We searched on Pub Med from inception to March 2016.Summary weighted mean difference（WMD） and 95% confidence intervals（CIs） were used to analyze the datum.Random-effects or fixed-effects models were chosen up to between-study heterogeneity.The main outcomes were composed of the Ocular Surface Disease Index（OSDI） scores,tear film break-up time（TBUT）,Schirmer Test and corneal sensitivity.RESULTS：Eight eligible studies including 772 eyes（386 in SMILE group and 386 in FS-LASIK group） were identified.The parameters have no significiant difference heterogeneity between SMILE and FS-LASIK group preoperatively.There were significant differences between the two groups in OSDI scores at one and three months postoperatively,in TBUT at one and three months postoperatively,in corneal sensitivity at one week,about one month and three months postoperatively.However,there was no significant difference observed in Schirmer Test at the follow-up periods.CONCLUSION：Compare to FS-LASIK,dry eye and the corneal sensitivity recover better in the SMILE group,in first three months after the surgery.

Three-year results of small incision lenticule extraction and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis for correction of high myopia and myopic astigmatism

AIM： To compare and calculate the 3-year refractive results, higher-order aberrations （HOAs）, contrast sensitivity （CS） and dry eye parameters after small incision lenticule extraction （SMILE） and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis （FS-LASIK） for correction of high myopia and myopic astigmatism. METHODS： In this prospective, non-randomized comparative study, 78 eyes with spherical equivalent （SE） of -8.11±1.09 diopters （D） received a SMILE surgery, and 65 eyes with SE of -8.05±1.12 D received a wavefront-guided FS-LASIK surgery with the VisuMax femtosecond laser （Carl Zeiss Meditec, Jena, Germany） for flap cutting. Visual acuity, manifest refraction, CS, HOAs, ocular surface disease index （OSDI） and tear break-up time （TBUT） were evaluated during a 3-year follow-up. RESULTS： The difference of uncorrected distance visual acuity （UDVA） postoperatively was achieved at lmo and at 3mo, whereas the difference of the mean UDVA between two groups at 3y were not statistically significant （t=-1.59, P=-0.13）. The postoperative change of SE was 0.89 D in the FS-LASIK group （t=5.76, P=0.00）, and 0.14 D in the SMILE group （t=-0.54, P=0.59） from lmo to 3y after surgery. At 3-year postoperatively, both HOAs and spherical aberrations in the SMILE group were obviously less than those in the FS-LASIK group （P=0.00）, but the coma root mean square （RMS） was higher in the SMILE group （0.59±0.26） than in the FS-LASIK group （0.29±0.14, P=0.00）. The mesopic CS values between two groups were not statistically significant at 3y postoperatively. Compared with the FS-LASIK group, lower OSDI scores and longer TBUT values were found in the SMILE group at Imo and 3mo postoperatively. With regard to safety, no eye lost any line of CDVA in both groups at 3y after surgery. CONCLUSION： Both SMILE and wavefront-guided FS- LASIK procedures provide good visual outcomes. Both procedures are effective and safe, but SMILE surgery achieve more stable long-term refractive outcome and better control of early postoperative dry eye as compared to FS-LASIK.

Corneal flap morphological analysis using anterior segment optical coherence tomography in laser in situ keratomileusis with femtosecond lasers versus mechanical microkeratome

AIM: To assess and compare the flap morphology using anterior segment optical coherence tomography (AS-OCT) in laser in situ keratomileusis (LASIK) with Femto LDV femtosecond lasers versus Hansatome mechanical Microkeratome. METHODS: AS-OCT (Visante) was used to compare 1 month postoperatively the morphology of the flaps created with Femto LDV femtosecond lasers or Hansatome Microkeratome. The intendedfiap thickness was 110 mu m and 160 mu m respectively. The thickness of twenty-five points across each flap, which were 0mm, 1.5mm, 2.5mm, and 3.5mm to the corneal vertex on the horizontal, vertical, 45 degrees and 135 degrees meridian respectively, was evaluated. RESULTS: One month postoperative, the central flap thickness in the Femto LDV group was 107.43 +/- 4.70 mu m, while 125.90 +/- 17.50 mu m in the Hansatome group. The difference between the actual and the expectedfiap thickness was 5.61 +/- 3.84 mu m and 31.52 +/- 12.27 mu m, respectively. The Hansatome group had presented a statistically significant result (P<0.001). Flap morphology showed a more regular planar shape in the Femto LDV group and a meniscus shape in the Hansatome group. CONCLUSION: AS-OCT is a direct and fast procedure to assess the flap morphology. The morphology by AS-OCT showed that the flaps created with Femto LDV femtosecond laser were more accurate and regular than the flaps created with Hansatome microkeratome.

Optical and visual quality comparison of implantable collamer lens and femtosecond laser assisted laser in situ keratomileusis for high myopia correction

AIM:To compare clinical outcomes and refractive stability of implantable collamer lens(ICL)implantation and femtosecond laser assisted laser in situ keratomileusis(FSLASIK)for high myopia correction.METHODS:The Optical Quality Analysis System(OQAS)was used to evaluate clinical outcomes objectively after operation for high myopia correction.We compared the two procedures in terms of 1-year changes in uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),safety index,efficacy index,spherical equivalent,modulation transfer function(MTF)cutoff frequency,strehl ratio(SR)and objective scatter index(OSI).RESULTS:At 1 y postoperatively,the safety indices were 1.33±0.27 in ICL group,and 1.17±0.24 in FS-LASIK group.39.58%in the ICL group and 27.59%in the FS-LASIK group gained CDVA in 2 lines or better than that in preoperative CDVA.The efficacy indices were 1.28±0.22 in ICL group,and 1.13±0.26 in FS-LASIK group.The changes of spherical equivalent from 1 wk to 1 y postoperatively was-0.12±0.37 D in ICL group,and-0.79±0.58 D in FS-LASIK group(P<0.05).Spherical equivalent within±0.50 D was achieved in 97.92%in ICL group and 68.97%in FS-LASIK group.MTF cutoff frequency were higher with ICL as compared to FSLASIK(P<0.05)at each postoperative follow-up stage;for postoperative 1 mo later,SR was statistically significant difference between two groups(P<0.05);with no statistically significant difference in OSI between two groups(P>0.05)in postoperative 3 mo later.CONCLUSION:ICL implantation and FS-LASIK procedures both provide good safety and predictability in high myopia correction.ICL implantation provides better clinical outcomes and refractive stability than FS-LASIK.

Clinical outcomes of small incision lenticule extraction versus femtosecond laser-assisted LASIK for myopia: a Meta-analysis

AIM：To evaluate the possible differences in visual quality between small incision lenticule extraction（SMILE）and femtosecond laser in situ keratomileusis（FS-LASIK）for myopia.METHODS：A Meta-analysis was performed.Patients were from previously reported comparative studies treated with SMILE versus FS-LASIK.The Pub Med,EMBASE,Cochrane,Web of Science and Chinese databases（i.e.WANFANG and CNKI）were searched in Nov.of 2016 using Rev Man 5.1 version software.The differences in visual acuity,aberration and biomechanical effects within six months postoperatively were showed.Twenty-seven studies including 4223 eyes were included.RESULTS：No significant differences were observed between SMILE and FS-LASIK in terms of the proportion of eyes that lost one or more lines of corrected distance visual acuity after surgery（P=0.14）,the proportion of eyes achieving an uncorrected distance visual acuity of 20/20or better（P=0.43）,the final refractive spherical equivalent（P=0.89）,the refractive spherical equivalent within±1.00diopter of the target values（P=0.80）,vertical coma（P=0.45）and horizontal coma（P=0.06）.Compared with the FSLASIK group,total higher-order aberration（P〈0.001）and spherical aberration（P〈0.001）were higher and the decrease in corneal hysteresis（P=0.0005）and corneal resistance factor（P=0.02）were lower in the SMILE group.CONCLUSION：SMILE and FS-LASIK are comparable in efficacy,safety and predictability for correcting myopia.However,the aberration in the SMILE group is superior to that in the FS-LASIK group,and the loss of biomechanical effects may occur less frequently after SMILE than after FS-LASIK.

Severe Diffuse Lamellar Keratitis Following Laser <i>in Situ</i>Keratomileusis with an Iatrogenic Double Flap

We present a case of an iatrogenic double flap created during laser in situ keratomileusis using a femtosecond laser microkeratome that resulted in development of severe diffuse lamellar keratitis (DLK). The DLK occurred mainly in the second interface, made by the spatula accidentally and not exposed to femtosecond or excimer lasers. Because of differences in the severity of the interface inflammatory reactions between the two layers exposed to the same spatula, an allergic reaction to detergent, bacteria, or other chemicals could not be assumed to be the main cause of DLK. Our observations in this case may suggest an important association of neural factors with DLK, because the inflammatory reaction occurred mainly in the deep stromal layer at the thick corneal nerves.

LASEK和TransPRK及FS-LASIK术后角膜屈光力及视觉质量比较

目的:比较准分子激光上皮下角膜磨镶术(LASEK)、经上皮准分子激光角膜切削术(TransPRK)、飞秒激光制瓣的准分子激光原位角膜磨镶术(FS-LASIK)三种角膜屈光手术术后角膜屈光力及视觉质量。方法:回顾性研究。选取2021-01/2022-12在我院择期行角膜屈光手术的232例464眼患者作为研究对象,根据患者选择手术方式不同分为LASEK组70例140眼、TransPRK组76例152眼、FS-LASIK组86例172眼。比较三组患者术前,术后1、3 mo时裸眼视力(UCVA)、视觉质量、生物力学稳定性、泪膜破裂时间(BUT)、泪液分泌试验(SⅠt)及生活质量变化情况。结果:术后1、3 mo三组患者裸眼视力较术前均改善,全角膜总高阶像差、球差、水平彗差、垂直彗差均升高,生物学稳定性均降低(均P<0.05)。术后3 mo, TransPRK组、LASEK组生物学稳定性均高于FS-LASIK组(均P<0.05),TransPRK组生活质量评分较LASEK组及FS-LASIK组高(P<0.05)。手术前后三组患者BUT、SⅠt比较均无差异(均P>0.05)。结论:LASEK、TransPRK、FS-LASIK三种角膜屈光手术治疗屈光不正疗效确切,在改善裸眼视力和提高视觉质量方面结果相似,但TransPRK、LASEK较FS-LASIK具有更稳定的生物力学性能,且TransPRK组在改善患者生活质量方面具有更好的效果。

SMILE和WG-FS-LASIK治疗低度无散光近视患者术后早期视觉质量比较

目的比较飞秒激光小切口角膜基质内透镜取出术(SMILE)和波前像差引导的准分子激光原位角膜磨镶术(WG-FS-LASIK)治疗低度无散光近视患者术后的早期视觉质量。方法选择2022年3月至6月在广西壮族自治区人民医院视光中心行SMILE治疗的患者15例(30眼,SMILE组),行WG-FS-LASIK治疗的患者15例(30眼,WG-FS-LASIK组)。所有患者术前无散光且最佳矫正视力所需最低球镜度数均≤-3.00 D。于术前和术后1 d、1周、1个月测量视力、全眼像差(慧差、三叶草像差和球差)、客观散射指数(OSI)、调制传递函数截止频率(MTF_(cut-off))、斯特列尔比(SR)、可预测对比度视力(PVA)(包括PVA 100%、PVA 20%、PVA 9%)。比较两组观察指标测量结果。结果两组术后等效球镜、视力情况均较术前显著改善(P<0.05),但两组各时间点比较差异无统计学意义(P>0.05)。两组术后OSI、SR、PVA 9%均较术前显著改善(P<0.05)。WG-FS-LASIK组在术后1 d、1周、1个月的OSI水平均显著低于SMILE组(P<0.05)。在术后1个月,WG-FS-LASIK组PVA 9%显著高于SMILE组(P<0.05)。SMILE组和WG-FS-LASIK组术后慧差均呈先上升后下降的趋势,但WG-FS-LASIK组变化幅度更小,在术后1 d、1周、1个月,WG-FS-LASIK组慧差小于SMILE组,差异有统计学意义(P<0.05)。结论SMILE和WG-FS-LASIK均能提高低度无散光近视患者术后早期视觉质量,但WG-FS-LASIK早期视力恢复更好,且夜间视觉质量改善更优。

角膜地形图引导的飞秒制瓣准分子激光手术治疗近视合并散光患者的效果

目的:观察角膜地形图引导的飞秒制瓣准分子激光手术(FS-LASIK)治疗近视合并散光患者的效果。方法:选取2018年7月至2023年7月梅州爱尔眼科医院收治的68例(136只眼)近视合并散光患者进行前瞻性研究,按照随机数字表法将其分为对照组和观察组各34例(68只眼)。对照组实施普通FS-LASIK治疗,观察组实施角膜地形图引导的FS-LASIK治疗。比较两组治疗前后视力[裸眼视力(UCVA)、最佳矫正视力(BCVA)、等效屈光度(SE)]水平、角膜高阶像差指标[总高阶像差(HOA)、彗差(Coma)、球差(SA)]水平、散光矫正指标[成功指数(IOS)、变平指数(FI)、矫正指数(CI)]水平和并发症发生率。结果:术后3个月,两组SE水平均高于术前,且观察组高于对照组,差异有统计学意义(P<0.05);两组BCVA、UCVA水平均低于术前,但组间比较,差异无统计学意义(P>0.05);两组HOA、Coma、SA水平均高于术前,但观察组低于对照组,差异有统计学意义(P<0.05);观察组IS、CI水平均低于对照组,FI水平高于对照组,差异有统计学意义(P<0.05);两组均未发生严重并发症。结论:角膜地形图引导的FS-LASIK治疗近视合并散光患者,可提高等效屈光度,改善散光矫正指标水平,降低角膜高阶像差指标水平,效果优于普通FS-LASIK治疗效果。

FS-LASIK Xtra治疗中高度近视患者术后2a的矫正效果

目的:评估FS-LASIK Xtra治疗中高度近视患者术后2 a的矫正效果及角膜形态的稳定性。方法:回顾性病例对照研究。纳入2019-08/2020-08在我院拟行屈光手术的中高度近视合并散光患者30例58眼,根据术前角膜地形图中圆锥角膜筛查相关指数行不同手术方式,分为FS-LASIK Xtra组15例29眼,FS-LASIK组15例29眼。术前,术后3 mo,1、2 a观察裸眼视力(UCVA)、最佳矫正视力(BCVA)、等效球镜度(SE)及Sirius三维角膜地形图仪测量的不同直径区域(3、5、7 mm)前后表面角膜曲率。结果:两组患者术后不同时间点UCVA均较术前明显提高(均P<0.01),两组间UCVA和SE比较均无差异(P>0.05)。术后2 a,FS-LASIK Xtra组25眼(86%),FS-LASIK组24眼(83%)残余散光为-0.25-0 D。两组实际矫正SE与预矫正SE均呈正相关(均P<0.05)。两组患者术后3 mo,1、2 a不同直径区域(3、5、7 mm)前后表面角膜曲率均较术前有差异(均P<0.05),术后1、2 a FS-LASIK Xtra组角膜直径3、5 mm后表面曲率均高于FS-LASIK组(P<0.05)。结论:FS-LASIK Xtra治疗中高度近视患者有良好的安全性、有效性及可预测性。

DIAGNOSIS AND TREATMENT FOR DEGENERATIVE RETINOSCHISIS OF MEDIUM TO HIGH MYOPIA IN YOUNG ADULTS PRIOR TO LASER-ASSISTED IN SITU KERATOMILEUSIS SURGERY

Objective To discuss the characteristics of degenerative retinoschisis in young adults with medium to high myopia prior to laser-assisted in situ keratomileusis(LASIX) surgery and the significance of preventive photocoagulation.Methods A total of 32 eyes in 19 patients suffering from myopia combined with degenerative retinoschisis were included.The mean best-corrected visual acuity was 0.82±0.13 and the mean spherical equivalent of the subjective refraction was -(6.50±3.98) Diopter. The patients underwent preventive photocoagulation 1 month before the laser surgery for myopia.Results All the eyes that received preventive photocoagulation for retinoschisis had no further progression or retinal detachment during 4-year period of follow-up.Conclusion The degenerative retinoschisis in young adults should be recognized and treated with preventive photocoagulation.This may prevent further damage of visual field and other complications of slowly progressive retinoschisis after LASIK surgery.

Femtosecond laser corneal refractive surgery for the correction of high myopic anisometropic amblyopia in juveniles

AIM： To evaluate the effects of femtosecond laser-assisted in situ keratomileusis（FS-LASIK） and small-incision lenticule extraction（SMILE） to correct high myopic anisometropic amblyopia in juvenile patients. METHODS： From November 2013 to January 2015, 33 amblyopic patients with high myopic anisometropic amblyopia were studied. FS-LASIK（30 eyes） or SMILE（3 eyes） was performed in the amblyopic eyes. Visual acuity, refraction, contrast sensitivity, stereoacuity and complications were evaluated. Patients completed followup examinations at 3 d, 1 mo, 3 mo and the last follow-up time（mean 8.17±3.23 mo） after surgery. RESULTS： The mean age at surgery was 9.04±3.04 y（range 6-16 y）. The mean spherical equivalent in the amblyopic eyes was significantly decreased from-10.00±2.39 D preoperatively to-0.06±1.06 D at 1 mo,-0.19±1.33 D at 3 mo and-0.60±1.43 D at approximately 8 mo postoperatively（P〈0.05 for all）. The mean myopic anisometropia was significantly decreased from-9.45±2.33 D preoperatively to ＋0.37±1.48 D at 1 mo,-0.46±1.47 D at 3 mo and-0.09±1.83 D at approximately 8 mo（P〈0.05 for all）. The logarithm of the minimum angle of resolution（log MAR） for uncorrected and corrected distance visual acuity（UDVA and CDVA, respectively） of the amblyopic eye improved from 1.74±0.35 and 0.98±0.63 preoperatively to 0.45±0.31 and 0.41±0.33 at approximately 8 mo after surgery, respectively. The logM AR CDVA at 3 d, 1, 3 and 8 mo postoperatively improved by means of 1.42, 2.22, 2.96, and 4.39 lines, and a gain of more than two lines accounted for 45%, 50%, 74% and 86% of all patients, respectively. The contrast sensitivity of both amblyopic eyes and dominant eyes at 0.5, 2, 8 cycles perdegree was significantly improved postoperatively（P〈0.05 for all）. Of the 33 pediatric patients, no patients had near stereopsis preoperatively and seven patients（21.2%） recovered near stereopsis（400″ to 60″） at approximately 8 mo after surgery. No intraoperative or postoperative complications occurred in any patient.CONCLUSION： FS-LASIK or SMILE can be promising alternative methods to correct high myopic anisometropic amblyopia in juvenile patients who have failed with traditional approaches.

SMILE和超薄瓣FS-LASIK矫正中度近视疗效比较

目的比较飞秒激光小切口角膜基质透镜取出术(SMILE)和超薄瓣飞秒激光辅助准分子激光原位角膜磨镶术(FS‐LASIK)矫正中度近视的临床疗效。方法回顾性病例对照研究。本研究纳入了年龄、性别和角膜厚度匹配合适的中度近视(等效球镜度-3.00~-6.00 D)患者,36例接受SMILE治疗患者的72只眼和36例接受超薄瓣FS‐LASIK治疗患者的72只眼。分别于术前及术后3个月记录所有患者的视力、屈光度及角膜高阶像差等变量,最后进行统计学分析以评估手术疗效。结果在术后随访3个月时,SMILE组和超薄瓣FS‐LASIK组疗效指数和安全指数比较,差异无统计学意义(t=1.179和-0.255,P=0.242和0.800)。SMILE组和超薄瓣FS‐LASIK组术后屈光度呈正视并相对稳定,术后等效球镜度比较差异无统计学意义(t=0.206,P=0.837)。SMILE组和超薄瓣FS‐LASIK组患者的角膜后表面曲率和非球面因子Q值比较,差异无统计学意义(t=-1.852和0.576,P=0.066和0.566)。SMILE组和超薄瓣FS‐LASIK组患者术前的总高阶像差、球差及彗差与术后比较,差异均具有统计学意义(均P<0.05)。在术后3个月时,SMILE组患者的总高阶像差及球差明显低于超薄瓣FS‐LASIK组(均P<0.05)。结论SMILE和超薄瓣FS‐LASIK两种术式矫治中度近视均安全有效,但SMILE组患者的术后总高阶像差及球差增加量低于超薄瓣FS‐LASIK组。

Stromal lenticule addition keratoplasty with corneal crosslinking for corneal ectasia secondary to FS-LASIK:a case series

●AIM:To explore the clinical efficacy and safety of stromal lenticule addition keratoplasty(SLAK)with corneal crosslinking(CXL)on patients with corneal ectasia secondary to femtosecond laser-assisted in situ keratomileusis(FS-LASIK).●METHODS:A series of 5 patients undertaking SLAK with CXL for the treatment of corneal ectasia secondary to FS-LASIK were followed for 4-9mo.The lenticules were collected from patients undertaking small incision lenticule extraction(SMILE)for the correction of myopia.Adding a stromal lenticule was aimed at improving the corneal thickness for the safe application of crosslinking and compensating for the thin cornea to improve its mechanical strength.●RESULTS:All surgeries were conducted successfully with no significant complications.Their best corrected visual acuity(BCVA)ranged from 0.05 to 0.8-2 before surgery.The pre-operational total corneal thickness ranged from 345-404μm and maximum keratometry(Kmax)ranged from 50.8 to 86.3.After the combination surgery,both the corneal keratometry(range 55.9 to 92.8)and total corneal thickness(range 413-482μm)significantly increased.Four out of 5 patients had improvement of corneal biomechanical parameters(reflected by stiffness parameter A1 in Corvis ST).However,3 patients showed decreased BCVA after surgery due to the development of irregular astigmatism and transient haze.Despite the onset of corneal edema right after SLAK,the corneal topography and thickness generally stabilized after 3mo.●CONCLUSION:SLAK with CXL is a potentially beneficial and safe therapy for advanced corneal ectasia.Future work needs to address the poor predictability of corneal refractometry and compare the outcomes of different surgical modes.

飞秒激光小切口角膜基质透镜取出术治疗近视性屈光参差

目的:探讨飞秒激光小切口角膜基质透镜取出术(SMILE)治疗近视性屈光参差的临床效果。方法:回顾性分析2021-01/2022-12于本院行SMILE或FS-LASIK治疗的近视性屈光参差患者76例146眼的临床资料,根据手术方式分为SMILE组(39例77眼)和FS-LASIK组(37例69眼)。比较两组患者术后1 wk,1、3 mo裸眼视力(UCVA)、屈光度、屈光参差度、角膜像差及术后并发症发生情况。结果:两组患者术后UCVA均较术前改善,彗差、三叶草、球差、总高阶像差均较术前显著增加(P<0.05),且FS-LASIK组患者彗差、三叶草、球差、总高阶像差显著高于SMILE组(P<0.05)。随访至术后3mo,SMILE组术后并发症发生率显著低于FS-LASIK组(5.2%vs 15.9%,P<0.05)。结论:SMILE与FS-LASIK均可有效提高近视性屈光参差患者UCVA,改善视觉质量,但SMILE术后角膜高阶像差更低、并发症发生率更小,整体效果更好。

FS-LASIK矫正中高度近视术后1年屈光回退危险因素及其预测模型构建

目的:探讨飞秒激光辅助准分子激光原位角膜磨镶术(FS-LASIK)矫正中高度近视术后1 a屈光回退的危险因素并构建预测模型。方法:回顾性分析2017-06/2018-11于西安高新医院行FS-LASIK手术矫正中高度近视患者400例800眼临床资料,将患者按照3∶1的比例随机分为建模组(n=300例)和验证组(n=100例),依照患者术后1 a屈光回退发生情况将建模组分为回退组与未回退组两个亚组,观察其角膜曲率和角膜厚度变化情况,采用Logistic回归分析筛选FS-LASIK矫正中高度近视患者术后1 a屈光回退的危险因素,基于回归系数构建预测模型,采用受试者工作特征曲线(ROC)评估模型区分度。结果:建模组44眼、验证组15眼于术后1 a发生屈光回退。建模组中未回退组术后6、12 mo时角膜前表面曲率低于回退组(均P<0.05);术后1、3、6、12 mo时回退组角膜增生程度大于未回退组(均P<0.05);FS-LASIK矫正中高度近视患者术后1 a屈光回退发生概率值回归方程为:P=1/[1+e^(-(-5.989+0.127×年龄+2.019×术前屈光度-0.022×术前角膜中央厚度+0.043×切削深度-1.569×切削光学区直径))],Hosmer-Lemeshow检测回归方程拟合优度(P=0.818),利用建模组数据进行内部验证,ROC曲线下面积为0.890(95%CI 0.843-0.937),灵敏度为81.82%,特异度为84.71%;利用验证组数据进行外部验证,ROC曲线下面积为0.838(95%CI 0.717-0.959),灵敏度为80.00%,特异度为87.57%。结论:构建的风险模型判别效度良好,可用于识别中高度近视患者行FS-LASIK术后1 a屈光回退高危人群。

Comparison of visual acuity, refractive results and complications of femtosecond laser with mechanical microkeratome in LASIK

AIM: To compare the outcomes of laser in situ keratomileusis (LASIK) performed with a femtosecond laser (Femtec, Technolas Perfect Vision GmbH, Germany) versus a mechanical microkeratome (Hansatome, Bausch and Lomb, USA) for the correction of myopia and astigmatism. ·METHODS: In this retrospective study, patients who had undergone LASIK using the 80 -kHz Femtec femtosecond laser were compared to age- and refraction- matched patients in whom the Hansatome microkeratome was used. Refractive and visual results 1 month and 3 months postoperatively, and complication rates were compared between the two groups. ·RESULTS: A total of 280 eyes were analyzed (140 in each group). At 3 months postoperatively in the Femtec vs Hansatome group, spherical equivalent refraction was within ±1.00D of emmetropia in 140 vs 138 eyes (P = 0.498), the cylinder was within ±0.50D in 137 vs 139 eyes (P =0.622), and the UDVA was 20/20 or better in 136 vs 137 eyes (P =0.724), respectively. There was no statistically significant difference in the complication rates between the two groups (P =0.099). ·CONCLUSION: LASIK performed both with Femtec femtosecond laser and Hansatome microkeratome achieved satisfactory refractive and visual results at 3 months postoperatively, without significant differences in efficacy, safety, and complication rates between the two procedures.

Effect of suction on macular thickness and retinal nerve fiber layer thickness during LASIK used femtosecond laser and Moria M2 microkeratome

·AIM: To compare the effect of suction on the macular thickness and retinal nerve fiber layer(RNFL) thickness during laser in situ keratomileusis(LASIK) used Ziemer FEMTO LDV femtosecond laser(Ziemer group) and Moria M2 automated microkeratome(Moria group) for flap creation.· METHODS: Fourier-domain optical coherence tomography(FD-OCT) was used to measure macular thickness, ganglion cell complex thickness and RNFL thickness of 204 eyes of 102 patients with the Ziemer femtosecond laser(102 eyes) and the Moria M2microkeratome(102 eyes) before surgery and 30min; 1,3d; 1wk; 1, 3mo; 1y after surgery.· RESULTS: The average foveal thickness and parafoveal retinal thickness 30 min after the surgery were statistically more than that before surgery(Ziemer P 【0.001,P =0.003 and Moria P=0.001, P=0.006) and the effect was less in the Ziemer group than that in the Moria group(P all 【0.05). The ganglion cell complex thickness was not significantly changed in both groups(P all 】0.05). The RNFL thickness was statistically less 30 min after surgery in both groups(P=0.014, P 【0.001), but the influence was less in Ziemer group than that in Moria group(P =0.038).However, the RNFL thickness had recovered to the preoperative level only 1d after surgery.·CONCLUSION: The suction of femtosecond laser and mechanical microkeratome led to the increase in macular central fovea thickness and the decrease in RNFL thickness values at the early stage after LASIK. The effect of suction on macular and the RNFL thicknesses in Ziemer group is smaller than that in Moria group.

Comparison of corneal flap thickness using a FS200femtosecond laser and a moria SBK microkeratome

AIMTo evaluate differences in flap thickness resulting from use of an Alcon Wavelight FS200 femtosecond laser and a MORIA SBK microkeratome when making a 110-&#x000b5;m-thick corneal flap and to identify the potential factors that affect corneal flap thickness.

Comparative study of visual acuity and aberrations after intralase femtosecond LASIK:small corneal flap versus big corneal flap

AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap,defined as the small flap,while the other eye was treated with a 8.6mm diameter corneal flap,defined as the big flap.Refractive errors,visual acuity,and higher-order aberrations were compared between the two groups at week 1,month 1 and 3 postoperatively. RESULTS:The postoperative refractive errors and visual acuity all conformed to the intended goal.Postoperative higher-order aberrations were increased,especially in spherical aberration(Z12) and vertical coma(Z7).There were no statistically significant differences between the two groups in terms of postoperative refractive errors,visual acuity,root mean square of total HOAs(HO-RMS),trefoil 30°(Z6),vertical coma(Z7),horizontal coma(Z8),trefoil 0°(Z9),and spherical aberration(Z12) at any point during the postoperative follow-up.CONCLUSION:Both the small and big flaps are safe and effective procedures to correct myopia,provided the exposure stroma meets the excimer laser ablations.The personalized size corneal flap is feasible,as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.