Early visual function outcomes of topography-guided FS-LASIK and SMILE in treatment of myopia and myopic astigmatism

AIM: To compare the quality outcomes of vision at early phase after topography-guided femtosecond laser-assisted in situ keratomileusis(FS-LASIK-CV) and small incision lenticule extraction(SMILE) in treatment of myopia and myopic astigmatism.METHODS: Retrospective comparative analysis of 49 patients that underwent FS-LASIK(n=23) or SMILE(n=26) procedure for myopia and myopic astigmatism between April and September in 2019. Pre-and postoperative uncorrected visual acuity(UCVA), spherical equivalent refraction(SEQ), cylindrical refraction, contrast sensitivity function(CSF), and corneal higher-order aberrations(HOAs) were evaluated. Independent t-test was used for inter-group comparison, while repeated measures ANOVA was used to analyze changes at different time points. RESULTS: In both groups, 100% of the eyes obtained a UCVA of 20/20 or better at 1 wk, 1, and 3 mo postoperatively. At 1 d and 3 mo postoperatively, UCVA was better in FS-LASIKCV group than in SMILE group. At 1 wk postoperatively, SEQ was lower in SMILE group than in FS-LASIK-CV group(P=0.006). At 3 mo postoperatively, the SEQ reached target refraction in both groups. The residual astigmatism was reduced in both groups without intergroup difference(P>0.05). At 3 mo postoperatively, the spherical aberration and coma under 6 mm pupil size were higher than preoperative levels in both groups(P<0.05). However, the increase in the corneal HOAs in the FS-LASIK-CV group was less than the SMILE group(P<0.05). At 3 mo postoperatively, the log CS were better than preoperative levels under scotopic conditions without glare and scotopic conditions with glare in both groups(P<0.05). At 1 and 3 mo postoperatively, under scotopic conditions without glare and scotopic conditions with glare, FS-LASIK-CV group showed more improvement in log CS at two spatial frequencies(12.0 c/d and 18.0 c/d;P<0.05).CONCLUSION: Both FS-LASIK-CV and SMILE demonstrate to be safe, effective, and predictable in treatment of myopia and myopic astigmatism. Early postoperative improvement in UCVA and CSF at high spatial frequency under scotopic conditions were better after FS-LASIK-CV than SMILE.

Multifocal and extended depth of focus intraocular lenses

Advances in intraocular lens(IOL)design have rendered cataract surgery a refractive procedure.Newer IOL types include bifocal,trifocal and extended depth of focus(EDOF)IOLs.Their basic difference nestles in the number of focal points that each lens provides,which in turn leads to different visual outcomes.Familiarity of surgeons with the various characteristics of each lens is of utmost importance for accurate IOL selection to match each patient’s needs.In this review,we aim to compare the clinical outcomes after implantation of multifocal and EDOF IOLs in terms of distance,intermediate and near vision,contrast sensitivity,and reading performance.Finally,we discuss the defocus curve and the optical and photic phenomena associated with each type of IOL.