Clinical efficacy of femtosecond laser-assisted phacoemulsification in diabetic cataract patients

BACKGROUND Diabetic patients with cataracts encounter specific difficulties during cataract surgery due to alterations in microcirculation,blood supply,metabolism,and the microenvironment.Traditional phacoemulsification may not fully tackle these issues,especially in instances with substantial preoperative astigmatism.The utilization of femtosecond laser-assisted phacoemulsification,in conjunction with Toric intraocular lens(IOL)implantation,offers a potentially more efficient strategy.This research seeks to evaluate the efficacy and possible complications of this approach in diabetic cataract patients.AIM To investigate the clinical efficacy and complications of femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation in diabetic cataract patients,comparing it with traditional phacoemulsification methods.METHODS This retrospective study enrolled 120 patients with diabetes cataract from May 2019 to May 2021.The patients were divided into two groups:the control group underwent traditional phacoemulsification and Toric IOL implantation,while the treatment group received Len Sx femtosecond laser-assisted treatment.Outcome measures included naked eye vision,astigmatism,high-level ocular phase difference detection,clinical efficacy,and complication.RESULTS There were no significant preoperative differences in astigmatism or naked eyesight between the two groups.However,postoperative improvements were observed in both groups,with the treatment group showing greater enhancements in naked eye vision and astigmatism six months after the procedure.High-level corneal phase difference tests also indicated significant differences in favor of the treatment group.CONCLUSION This study suggests that femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation appears to be more effective in enhancing postoperative vision in diabetic cataract patients compared to traditional methods offering valuable insights for clinical practice.

Comparison of visual performance with iTrace analyzer following femtosecond laser-assisted cataract surgery with bilateral implantation of two different trifocal intraocular lenses

AIM:To compare the postoperative binocular visual performance with an iTrace analyzer following femtosecond laser-assisted cataract surgery(FLACS)combined with bilateral implantation of two different types of diffractive trifocal intraocular lenses(IOL).METHODS:During this retrospective observational study,patients who received bilateral FLACS combined with implantation of two different types of diffractive trifocal IOLs were evaluated.According to the IOLs’different types and design,the patients were divided into AT LISA tri839MP group(tri839 group)and AcrySof PanOptix TFNT00 group(TFNT group).Study parameters included preoperative and postoperative uncorrected distance visual acuity(UDVA)at 5 m,uncorrected near visual acuity(UNVA)at 30 cm and 40 cm,uncorrected intermediate visual acuity(UIVA)at 60 cm and 80 cm,postoperative refractive status,objective visual qualities and total high order aberrations(HOAs)postoperatively.The postoperative complications were also recorded.RESULTS:Totally 56 eyes of 28 patients(tri839 group,n=26;TFNT group,n=30)were included.Preoperative baseline characteristics between groups were not statistically significantly different.UDVA was not significantly different between groups except for 1wk follow-up due to the postoperative corneal edema.TFNT group showed statistically significant better UNIA at 60 cm than tri839 group at the 1wk(0.05±0.19 vs 0.15±0.10 logMAR,P=0.013),1mo(0.05±0.12 vs 0.15±0.09 logMAR,P=0.001)and 3mo(0.04±0.12 vs 0.15±0.11 logMAR,P=0.001)follow-up,while tri839 group showed statistically significant better UNIA at 80 cm than TFNT group at the 1d(0.14±0.15 vs 0.20±0.14 logMAR,P=0.041)and 1mo(0.09±0.07 vs 0.14±0.10 logMAR,P=0.042)follow-up.Postoperative refractive status showed stable at every visit.Modulated transfer function(MTF)values and strehl ratio(SR)values were improved and HOAs were lower significantly after surgery.CONCLUSION:FLACS with bilateral implantations of both tri839 and TFNT00 can achieve satisfactory natural whole-course vision,high postoperative refractive stability and good visual quality but without significantly difference.iTrace aberration instrument can accurately evaluate the visual quality under different status.

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。

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。

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.

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.

Changes in ocular surface status and dry eye symptoms following femtosecond laser-assisted cataract surgery

AIM: To observe the changes in ocular surface and the dry eye symptoms following femtosecond laser-assisted cataract surgery(FLACS). METHODS: Patients with no eye signs or symptoms in Guangzhou Aier Eye Hospital between October 2017 and September 2018, who underwent FLACS and intraocular lens(IOL) implantation for age-related cataract were enrolled. Tear film stability assessed with OCULUS Keratograph 5 M, Schirmer’s I test(SIT), and corneal fluorescein staining(CFS) were evaluated before and after surgery at 1 d, 1 wk, 1, and 3 mo in order. Ocular Surface Disease Index scores(OSDI) and Subjective Symptom Questionnaires(SSQs) were recorded at the same time point.RESULTS: Thirty-eight eyes of 38 patients were enrolled. The noninvasive tear film break-up time(first break-up time and average break-up time) decreased in a peak at the 1 wk visit, and then increased to basic levels at 1 mo. The tear meniscus height(TMH) increased transiently at 1 d, and declined in the following 3 mo visits. The SIT had a transient increase at 1 d(P=0.357) and a decrease at 1 wk and 1 mo(both P<0.05) but returned to the preoperative levels at 3 mo after surgery(P=0.062). CFS scores were significantly improved compared with those before surgery, and had a statistical difference(P<0.05). OSDI scores and SSQs after surgery were obviously higher, and had a statistical difference(P<0.001) but didn’t return to the basic level by 3 mo. CONCLUSION: Dry eye signs and symptoms can occur immediately following FLACS and have a peak severity on day 7 postoperatively. Most signs of dry eye can return to preoperative basic levels within 3 mo postoperatively. However, all cases can not recover from CFS and dry eye symptoms at 3 mo postoperatively.

Comparison of perioperative parameters in one-handed rotational phacoemulsification versus conventional phacoemulsification and femtosecond laser-assisted cataract surgery

AIM:To compare perioperative parameters of one-handed rotational phacoemulsification technique(one-handed phaco-roll)with each of other two techniques,“Divide et Conquer”and femtosecond laser-assisted cataract surgery(FLACS)METHODS:In this retrospective and comparative cohort study,eyes with uncomplicated cataract(nuclear density grade 2 to 3)treated routinely with one-handed phacoroll(n=23;Group 1)or“Divide et Conquer”(n=23;Group 2)or FLACS(n=23;Group 3)were enrolled.Intraoperative parameters including effective phaco-time(EPt),ultrasound time(USt),aspiration time,surgical time,phacoemulsification(phaco)-power,balanced salt solution(BSS)use,cumulative dissipated energy(CDE)were recorded and compared.Clinical outcomes including best corrected visual acuity(BCVA),corneal endothelial cell density(ECD),endothelial cell loss(ECL),central corneal thickness(CCT)and central macular thickness(CMT),were assessed and compared pre-operatively and at 1mo after surgery.RESULTS:Aspiration and surgical time,and BSS used were lower in Group 1(P<0.01)than other groups.EPt,phaco-power and CDE were lower in Group 1(P<0.05)than Group 2 but not significantly different from Group 3.In Group 1,USt was lower(P<0.05)than Group 2 but higher(P<0.05)than Group 3.BCVA improved in all groups without significant difference between Group 1 and the other ones.No significant differences regarding all post-operative morphologic outcomes(ECD,ECL,CCT,CMT)were reported.No clinical complications occurred.CONCLUSION:One-handed phaco-roll seems to be less time-consuming than“Divide et Conquer”and FLACS and less energy-consuming than“Divide et Conquer”.Furthermore,one-handed phaco-roll seems to have an equal safety profile compared to the other two techniques.

Effect of femtosecond laser-assisted lens surgery on the optic nerve head and the macula

AIM: To evaluate the effect of femtosecond laser-assisted lens surgery(FLALS;cataract surgery or refractive lens exchange) on the structure of the optic nerve head and the macula.METHODS: This prospective longitudinal study included healthy eyes undergoing FLALS. Eyes with glaucoma or any other ocular disease that could alter optical coherence tomography results were excluded. Retinal nerve fiber layer(RNFL), Bruch’s membrane opening-minimum rim width(BMO-MRW) and macular thickness(MT) were measured preoperatively, 1 and 6 mo after surgery using spectral-domain optical coherence tomography(SD-OCT). Changes between preoperative and postoperative values were evaluated.RESULTS: A total of 87 eyes of 46 patients were included in this study. Preoperative RNFL, BMO-MRW and MT in microns(μm) were 100.77±10.39, 330.31±49.99 and 276.30±33.39, respectively. Postoperative RNFL, BMO-MRW and MT were 104.74±11.55, 348.32±54.05 and 279.83±22.65 1 mo after surgery and 102.93±11.17, 343.11±53.4 and 278.90±22.19 6 mo after surgery, respectively;which equals an increase of 3.93%, 5.45% and 1.27%,respectively, 1 mo after surgery, and 2.14%, 3.87% and 0.94% 6 mo after surgery. The differences between the preoperative and the postoperative RNFL and BMO-MRW values were statistically significant(P<0.001). Regarding MT values, there were not statistically significant differences(P=0.26).CONCLUSION: Our study suggests that FLALS does not have a negative impact on the structural status of the optic nerve head in healthy eyes, assessed by SD-OCT. There is a slight increase in the values of RNFL, BMO-MRW and MT 1 mo and 6 mo after surgery.

Femtosecond laser-assisted deep anterior lamellar keratoplasty for keratoconus and keratectasia

·AIM: To describe the initial outcomes and safety of femtosecond laser-assisted deep anterior lamellar keratoplasty(DALK) for keratoconus and post-LASIK keratectasia.·METHODS: In this non-comparative case series, 10 eyes of 9 patients underwent DALK procedures with a femtosecond laser(Carl Zeiss Meditec AG, Jena,Germany). Of the 9 patients, 7 had keratoconus and 2had post-LASIK keratectasia. A 500 kHz VisuMax femtosecond laser was used to perform corneal cuts on both donor and recipient corneas. The outcome measures were the uncorrected visual acuity(UCVA),best-corrected visual acuity(BCVA), corneal thickness,astigmatism, endothelial density count(EDC), and corneal power.·RESULTS: All eyes were successfully treated. Early postoperative evaluation showed a clear graft in all cases. Intraoperative complications included one case of a small Descemet’s membrane perforation.Postoperatively, there was one case of stromal rejection,one of loosened sutures, and one of wound dehiscence.A normal corneal pattern topography and transparency were restored, UCVA and BCVA improved significantly,and astigmatism improved slightly. There was no statistically significant decrease in EDC.· CONCLUSION: Our early results indicate that femtosecond laser-assisted deep anterior lamellar keratoplasty could improve UCVA and BCVA in patients with anterior corneal pathology. This approach shows promise as a safe and effective surgical choice in the treatment of keratoconus and post-LASIK keratectasia.

Anterior and posterior capsule densitometry levels after femtosecond laser-assisted cataract surgery

AIM： To analyze and compare five different variables over one year follow-up（1 wk, 1, 3, 6 and 12 mo）： anterior capsule（AC）, and posterior capsule（PC） area densitometry values, AC and PC linear densitometry values, and AC opening area reduction ratio after femtosecond laserassisted cataract surgery. METHODS： This was a prospective comparative study. Seventy-one patients underwent femtosecond laser-assisted cataract surgery on single eye between June 2014 and December 2015. A 5.0 mm diameter laser assisted anterior capsulotomy was performed on all eyes. In every postsurgery evaluation, AC opacificaction（ACO） and PC opacification（PCO） density levels were provided by Oculus Pentacam·HR using area and linear densitometry methods. Digital images were captured with a slit-lamp Topcon photographic camera and IMAGEnet· 5 software. The AC opening area on the digital images was measured using the Sketchandcalc area calculator and converted to reduction ratio levels.RESULTS： Using Pearson correlation coefficient（PCC）, we found no correlation（r=-0.091, P=0.46） in the twelfth month assessment between the evolution of ACO area densitometry values and PCO area densitometry values considered as independent variables. We found no correlation, using PCC（r=-0.096, P=0.43） between the evolution of ACO linear densitometry values and PCO linear densitometry values, in the twelfth month visit, working both as independent variables. AC linear densitometry levels and AC area densitometry levels continued to grow strongly from sixth to twelfth months. Analysis of the values of AC opening area reduction ratio（1 wk, 1, 3, 6, 12 mo） revealed statistically significant differences between the values of successive examinations but the magnitude of the change decreased. In the final period of monitoring between six and twelve months the magnitude of change was low.CONCLUSION： Our results show strong increases of Scheimpflug ACO densitometry values from the sixth to the twelfth month while capsulorhexis area reduction ratio levels displayed a considerable decrease. We found no correlation between ACO area and linear densitometry values and PCO area and linear densitometry values, in the twelfth month examination, working as independent variables.

Combined Carbon Dioxide Laser Lateral Canthotomy and Femtosecond Laser-Assisted Cataract Surgery

Purpose: The purpose of this study was to evaluate a new procedure aimed at lengthening the palpebral fissure to facilitate femtosecond laser-assisted cataract surgery in patients with small eyes. Method: A quick procedure using the CO2 laser was adapted for patients with small eyes undergoing laser-assisted cataract surgery using the Catalys system. The UniPulse CO2 laser (Nidek) was used for laser lateral canthotomy on patients with small palpebral fissures to allow fitting of the Liquid OpticTM Interface eyepiece. Results: Lateral canthotomies were performed on 19 women and 7 men (ages ranged from 45 to 93 years) with lower eyelid lengths equal to or shorter than 32 mm who then underwent femtosecond laser-assisted cataract surgery. A total of 33 eyelids received laser lateral canthotomy with the CO2 laser;only one eyelid had lateral canthotomy with cold-steel tenotomy scissors. Dockings were completed for all 34 eyes with eyelids receiving lateral canthotomies. The 33 eyes with eyelids that received laser canthotomy with the CO2 laser had successful femtosecond laser-assisted cataract surgery. The one eye with the eyelid that received cold-steel canthotomy could not have femtosecond laser-assisted cataract surgery despite successful docking because of pupillary constriction. The findings were statistically significant;Fisher Exact Test showed a p-value of 0.0294. Conclusion: Laser lateral canthotomy with CO2 laser is a safe and effective method to allow docking and completion of femtosecond laser-assisted cataract surgery.

Case report:simultaneous femtosecond laser astigmatic keratotomy and toric intraocular lens implantation in femtosecond laser-assisted cataract surgery in a patient with surgically induced high corneal astigmatism

Background:Femtosecond laser astigmatic keratotomy(FSAK)and toric intraocular lens(IOL)implantation have been studied individually for comparison to treat astigmatism at cataract surgery.We report a case of surgically induced high corneal astigmatism by laser thermal keratoplasty(LTK)in a patient with cataract who was successfully treated with simultaneous combination of FSAK and toric IOL implantation with femtosecond laser-assisted cataract surgery(FLACS).This is the first report of both procedures combined simultaneously,with or without history of LTK.Case Description:A 68-year-old male presented with a history of LTK with two enhancements each eye in 2004,with subsequent surgically induced high corneal astigmatism,and with age-related nuclear cataract of both eyes.IOL master demonstrated+7.71 diopters of astigmatism at 163 degree right eye and+3.29 diopters of astigmatism at 4 degree left eye.After extensive discussion of the risks and benefits,the patient agreed to undergo FLACS with FSAK with two 61 degrees of relaxation incisions(RIs)and toric IOL(Alcon SN6AT9)right eye;FLACS with toric IOL(Alcon SN6AT7)alone left eye.At 2-year follow-up,uncorrected visual acuity was 20/30 right eye,20/25 left eye.His best corrected visual acuity was 20/25(+0.25+1.00 axis 21)right eye and 20/20(plano+0.25 axis 90)left eye;his best corrected near visual acuity was J1+with add+2.50 diopters right eye and left eye.Conclusions:Patients with age-related cataract and LTK induced high corneal astigmatism can hardly be sufficiently treated with FSAK or toric IOL alone at the time of cataract surgery.An effective way is to combine large FSAK and toric IOL of the highest cylindrical power of T9,in our case,simultaneously,which can achieve an excellent long term visual outcome.

Assessment of contrast sensitivity loss after intrastromal femtosecond laser and LASIK procedure

AIM： To assess the loss of contrast sensitivity （CS） function for INTRACOR or intrastromal femtosecond laser presbyopia procedure to conventional LASIK procedures.METHODS： Patients were recruited from a refractive surgery center for either INTRACOR or conventional LASIK. INTRACOR was performed on 8 eyes and LASIK was performed for 40 eyes in an overlapping period. Pre-operative evaluation and post-operative follow up for up to three months was done. Drops of CS in 4 spatial frequency （3 cpd, 6 cpd, 12 cpd and 18 cpd） right before and 3mo after the surgery were compared by Wilcoxon signed ranks test.RESULTS： For INTRACOR, CS threshold showed significant drop at both glare and non-glare condition, the drop was seen in all 4 spatial frequency. The averaged loss over the 4 spatial frequencies 3mo after surgery was 1.18 for non-glare and 0.71 for glare. For LASIK the CS threshold drop was most significant in 12 cpd for glare.CONCLUSION： INTRACOR procedure produces a gain of near vision for presbyopia patients but also introduces a high lost of contrast sensitivity plus worsen of vision quality. Pre-surgical patient selection and advise should be given with specific regards to night driving and glare conditions.

Comparative analysis of the clinical outcomes between wavefront-guided and conventional femtosecond LASIK in myopia and myopia astigmatism

AIM:To compare the clinical outcomes of wavefront guided femtosecond LASIK(WFG LASIK)and conventional femtosecond LASIK(NWFG LASIK)in eyes with myopia and myopia astigmatism.METHODS:This was a retrospective,nonrandomized,comparative investigation enrolling 236 eyes of 122 patients(18-50 y)with low&moderate and high myopia.The WFG group including 97 eyes(50 patients)undergone WFG LASIK and the NWFG group including 139 eyes(72 patients)undergone conventional LASIK.Mean efficacy index,high order aberrations(HOAs),pupil size and the quality of visual questionnaire were evaluated 6 mo postoperatively.RESULTS:There is no difference between WFG group(-0.054±0.049 in logMAR)and NWFG group(-0.040±0.056)in uncorrected distance visual acuity(UDVA)postoperatively.The myopia astigmatism is higher in WFG group than that in NWFG group(P<0.05).However,the mean efficacy index(MEI)in the WFG group(1.09±0.106)is better than that in the NWFG group(1.036±0.124;P<0.001).Increased HOAs were observed in NWFG group(0.30±0.196)than that in WFG group(0.146±0.188;P<0.001).The pupil size is larger in WFG group(5.15±0.76 mm)than that in NWFG group(4.32±0.52 mm).The patients are satisfied with the clinical surgery,yet WFG group showed better visual quality using the questionnaire survey.Meanwhile,high myopia would result in worse MEI,HOAs and visual quality than low&moderate myopia.CONCLUSION:WFG and NWFG FS-LASIK are both effective and safe procedures to correct low&moderate and high myopia,but WFG FS-LASIK gives a better postoperative MEI,aberrometric control and predictable outcome.Meanwhile,WFG FS-LASIK is better than NWFG FS-LASIK in correction of myopia astigmatism.Low&moderate myopia allow better clinical outcomes than high myopia using any surgical method.

Comparison of early changes in ocular surface markers and tear inflammatory mediators after femtosecond lenticule extraction and FS-LASIK

AIM:To compare the short-term impacts of femtosecond lenticule extraction(FLEx)and femtosecond laser-assisted laser in situ keratomileusis(FS-LASIK)on ocular surface measures and tear inflammatory mediators.METHODS:This prospective comparative nonrandomized clinical study comprised 75 eyes(75 patients).Totally 20 male and 15 female patients(age 21.62±3.25 y)with 35 eyes underwent FLEx,and 26 male and 14 female patients(age 20.18±3.59 y)with 40 eyes underwent FS-LASIK.Central corneal sensitivity,noninvasive tear breakup time,corneal fluorescein staining,Schirmer I test,tear meniscus height,and ocular surface disease index were evaluated in all patients.Tear concentrations of nerve growth factor(NGF),interleukin-1α(IL-1α),transforming growth factor-β1(TGF-β1),tumor necrosis factor-α(TNF-α),interferon-γ(IFN-γ),and matrix metalloproteinase-9(MMP-9)were assessed by multiplex antibody microarray.All measurements were performed preoperatively,and 1 d,1 wk,and 1 mo postoperatively.RESULTS:Patients who underwent FLEx exhibited a more moderate reduction in central corneal sensation and less corneal fluorescein staining than those in the FS-LASIK group 1 wk after the procedure(P<0.01).NGF was significantly higher 1 d and 1 wk after surgery in the FS-LASIK group than in the FLEx group(P<0.01).By contrast,compared to those in the FLEx group,higher postoperative values and slower recovery of tear TGF-β1,IL-1α,and TNF-αconcentrations were observed in the FS-LASIK group(P<0.01).Tear concentrations of NGF,TGF-β1,TNF-α,and IL-1αwere correlated with ocular surface changes after FLEx or FS-LASIK surgery.CONCLUSION:There is less early ocular surface disruption and a reduced inflammatory response after FLEx than after FS-LASIK.NGF,TGF-β1,TNF-α,and IL-1αmay contribute to the process of ocular surface recovery.

SMILE与FS-LASIK术后角膜光密度的变化研究

目的:比较飞秒激光小切口角膜基质透镜取出术(SMILE)与飞秒激光辅助制瓣的准分子激光角膜原位磨镶术(FS-LASIK)术后角膜光密度的变化,探讨SMILE术后角膜界面混浊对视觉的影响。方法:前瞻性队列研究。选取2020-05/2021-10在南通大学附属医院眼科屈光手术中心拟行角膜屈光手术的患者93例186眼,其中SMILE组48例96眼,FS-LASIK组45例90眼,观察两组患者术前和术后1d,1wk,1、3、6mo时角膜光密度、等效球镜、裸眼视力(UCVA)的变化。结果:纳入93例患者均顺利完成手术,术中及术后均未出现相关并发症,无失访病例。FS-LASIK组在术后1d,1wk UCVA分别为0.044±0.064和-0.001±0.065优于SMILE组(0.102±0.077和0.023±0.064)(均P<0.05)。两组间术后各随访时间的等效球镜均无差异(P>0.05)。FS-LASIK组术后1d在距角膜顶点0~2、2~6mm的角膜光密度及总角膜光密度分别为18.0(17.5,18.6)、16.2(15.6,16.7)、16.7(16.1,17.3),均低于SMILE组[18.6(18.1,19.3)、16.8(16.4,17.4)、17.2(16.6,17.8)](均P<0.05);FS-LASIK组术后1wk在距角膜顶点0~2、2~6mm处的角膜光密度及总角膜光密度分别为17.2(16.7,17.6)、15.5(15.0,15.9)、15.9(15.3,16.7),均低于SMILE组[17.6(17.1,18.3)、16.0(15.6,16.5)、16.6(15.9,17.1)](均P<0.05)。结论:SMILE术后出现的一过性界面混浊是导致其早期角膜光密度高于FS-LASIK的原因,界面混浊的出现或是视觉质量的影响因素。

角膜生物力学分析仪评估SMILE与FS-LASIK术后角膜生物力学的变化

目的:利用角膜生物力学分析仪(Corvis ST)评估行飞秒激光小切口角膜基质透镜取出术(SMILE)和飞秒激光辅助的准分子激光原位角膜磨镶术(FS-LASIK)治疗的中度屈光不正患者术后角膜生物力学的变化特征。方法:前瞻性队列研究。选取2020-11/2021-11在宁夏眼科医院视光中心拟行角膜屈光手术的中度近视患者65例130眼,考虑双眼存在关联,双眼同时满足条件选右眼进行研究,其中SMILE组30眼,FS-LASIK组35眼。应用Corvis ST观察两组患者术前、术后1、3mo角膜生物力学参数综合半径(IR)、反向凹面半径(ICR)、形变幅度比值(DAR2)、硬度指数(SP-A1)、相关厚度-水平方向(ARTh)和最大压陷曲率半径(HC-Radius)的变化。结果:两组间患者术前,术后1、3mo生物力学参数比较均无差异(P>0.05)。各组患者术后1、3mo IR、ICR、DAR2均较术前明显增加,SP-A1、ARTh、HC-Radius均较术前明显降低(均P<0.05),术后1mo与术后3mo生物力学参数比较无差异(P>0.05)。两组患者术后3mo中央角膜厚度(CCT)与ARTh和SP-A1呈正相关(FS-LASIK组:r=0.727、0.819,SMLIE组:r=0.683、0.434,均P<0.05),与IR和ICR呈负相关(FS-LASIK组:r=-0.697、-0.622,SMLIE组:r=-0.447、-0.491,均P<0.05)。结论:对于中度近视患者,SMILE和FS-LASIK术后均可导致角膜生物力学稳定性降低,两种手术方式对生物力学的影响无明显差异,且在术后1mo时生物力学趋于稳定,术后CCT与生物力学参数ARTh、SP-A1、IR和ICR存在相关性。

Comparison of visual performance recovery after thin-flap LASIK with 4 femtosecond lasers

AIM：To compare the speed of visual recovery following myopic thin-flap LASIK with four femtosecond lasers.METHODS：Eighty-eight eyes of 46 patients who were consecutively scheduled for bilateral LASIK with the Intra Lase FS60（Group 1）,Femto LDV Crystal Line（Group 2）,Wavelight FS200（Group 3）and Visu Max（Group 4）femtosecond lasers were enrolled in.Monocular uncorrected distance visual acuity（UDVA）,best-corrected distant visual acuity（CDVA）,refraction,contrast sensitivity and higher-order aberrations（HOAs）were evaluated at 1,3d,1wk and 1mo postoperatively.RESULTS：Sixteen eyes（72.7%）achieved 20/16 and 8eyes（36.4%）were 20/12.5 at 1d in Group 2,which was significantly more than other 3 groups.At 1wk,20 eyes（90.9%）achieved 20/16 in Groups 2 and 4.At 1mo,20 eyes（90.9%）achieved 20/16 in Group 2 and Group 4,which were significantly more than other two groups.While by1 mo,the difference of the residual spherical equivalent（SE）was not statistically significant among 4 groups（P=0.121）.The induction of spherical aberration（SA）were significantly less for Groups 2,3,4 than for Group 1 one day after surgery（P=0.015）.The differences among 4groups were not statistically significant before and after surgery on every time points（all P〉0.05）.CONCLUSION：The thin-flap LASIK procedure using the Femto LDV Crystal Line and Visu Max femtosecond laser show faster visual performance recovery.