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.

Comparative analysis of the efficacy of astigmatic correction after wavefront-guided and wavefront-optimized LASIK in low and moderate myopic eyes

AIM： To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis（LASIK） in eyes with myopic astigmatism using wavefront-guided（WFG） and wavefront-optimized（WFO） ablation profiles.METHODS： Prospective study included 221 eyes undergoing LASIK： 99 and 122 eyes with low and moderate myopic astigmatism（low and moderate myopia groups）.Two subgroups were differentiated in each group according to the ablation profile： WFG subgroup,109 eyes（45/64,low/moderate myopia groups） treated using the Advanced Custom Vue platform（Abbott Medical Optics Inc.）,and WFO subgroup,112 eyes（54/58,low/moderate myopia groups） treated using the EX-500 platform（Alcon）.Clinical outcomes were evaluated during a 6-month follow-up,including a vector analysis of astigmatic changes.RESULTS： Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group（P≤0.041）.Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups（P≤0.003）.In moderate myopia group,a higher percentage of eyes with a postoperative cylinder ≤0.25 D was found in the WFG subgroup（90.6% vs 65.5%,P=0.002）.In low and moderate myopia groups,the difference vector was significantly higher in the WFO subgroup compared to WFG（P〈0.001）.In moderate myopia group,the magnitude（P=0.008） and angle of error（P〈0.001） were also significantly higher in the WFO subgroup.Significantlyless induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups（P≤0.006）.CONCLUSION： A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.

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 optical quality after implantable collamer lens implantation and wavefront-guided laser in situ keratomileusis

AIM： To compare the optical quality after implantation of implantable collamer lens（ICL） and wavefront-guided laser in situ keratomileusis（WG-LASIK）.METHODS： The study included 40 eyes of 22 patients with myopia who accepted ICL implantation and 40 eyes of 20 patients with myopia who received WG-LASIK. Before surgery and three months after surgery, the objective scattering index（OSI）, the values of modulation transfer function（MTF） cutoff frequency, Strehl ratio, and the Optical Quality Analysis System（OQAS） values（OVs） were accessed. The higher order aberrations（HOAs） data including coma, trefoil, spherical, 2^（nd） astigmatism and tetrafoil were also obtained. For patients with pupil size 〈6 mm, HOAs data were analyzed for 4 mm-pupil diameter. For patients with pupil size ≥6 mm, HOAs data were calculated for 6 mm-pupil diameter. Visual acuity, refraction, pupil size and intraocular pressures were also recorded.RESULTS： In both ICL and WG-LASIK group, significant improvements in visual acuities were found postoperatively, with a significant reduction in spherical equivalent（P〈 0.001）. After the ICL implantation, the OSI decreasedslightly from 2.34±1.92 to 2.24±1.18 with no statistical significance（P=0.62）. While in WG-LASIK group, the OSI significantly increased from 0.68±0.43 preoperatively to 0.91±0.53 postoperatively（Wilcoxon signed ranks test, P=0.000）. None of the mean MTF cutoff frequency, Strehl ratio, OVs showed statistically significant changes in both ICL and WG-LASIK groups. In the ICL group, there were no statistical differences in the total HOAs for either 4 mmpupil or 6 mm-pupil. In the WG-LASIK group, the HOA parameters increased significantly at 4 mm-pupil. The total ocular HOAs, coma, spherical and 2^（nd） astigmatism were 0.12±0.06, 0.06±0.03, 0.00±0.03, 0.02±0.01, respectively. After the operation, these values were increased into 0.16±0.07, 0.08±0.05,-0.04±0.04, 0.03±0.01 respectively（Wilcoxon signed ranks test, all P〈0.05）. At 6 mm-pupil, the induction of total HOAs was not statistically significant in the WG-LASIK group. CONCLUSION： ICL implantation has a less disturbance to optical quality than WG-LASIK. The OQAS is a valuable complementary measurement to the wavefront aberrometers in evaluating the optical quality.

Evaluation of Clinical Outcomes after LASIK for the Correction of Myopia Using the Advanced Customvue Excimer Laser Platform

-Purpose: To evaluate early visual, refractive and aberrometric outcomes after wave front-guided LASIK for the correction of low to moderate myopia and myopic astigmat is musing the excimer laser platform Advanced Custom Vue. Methods: A prospective, non-comparative study in 100 myopic eyes of 50 patients evaluating LASIK results over a period of 3 months. Main outcome variables included visual acuity, refraction, total higher-order aberrations (HOAs), spherical aberration (SA) and coma-like aberration. The surgery was performed using the VISX STAR S4 (Johnson and Johnson Vision) excimer laser and a wave front-guided ablation designed according to the iDesign aberrometer data (Johnson and Johnson Vision). Results: Mean preoperative sphere decreased from -4.07 ± 1.78 D to 0.32 ± 0.30 D at 3 months after surgery. Mean preoperative cylinder was reduced from -1.09 ± 0.88 D to -0.26 ± 0.28 D after the complete follow-up. Postoperative uncorrected distance visual acuity (UDVA) was 0.00 logMAR (20/20) or better in 100% of eyes, and 65.3% of eyes reached an UDVA of -0.20 logMAR (20/12.5) or better (p < 0.05). For a 6-mm pupil, the root mean square (RMS) for total ocular HOAs increased with surgery by 0.03 μm (p = 0.050), whereas the coma-like RMS increased by 0.05 μm (p < 0.001). The change in spherical aberration was +0.08 μm (p < 0.001). Conclusion: Wavefront-guided LASIK using the new generation excimer laser platform Advanced Custom Vue is safe and effective for treating myopia and myopic astigmatism, minimizing the postoperative level of HOAs.