ABSTRACT
<p><b>BACKGROUND</b>Thin-flap laser in situ keratomileusis (LASIK) is the new trend of refractive error correction surgery, the formation of corneal flap is crucial for a success of LASIK surgery. This study aimed to assess and compare the variations of LASIK flap created by the IntraLase femtosecond laser, Moria One Use-Plus SBK and Moria M2 Single-Use 90 µm-head microkeratome using Anterior segment optical coherence tomography (Visante OCT).</p><p><b>METHODS</b>One hundred and sixty-one eyes of 81 consecutive patients were enrolled in this prospective study and randomly divided into three groups depending on the flap creation method: flap creation with the the IntraLase femtosecond laser (IntraLase group, 59 eyes), flap creation with the Moria One Use-Plus SBK (SBK group, 44 eyes), and flap creation with the Moria M2 Single-Use 90 µm-head microkeratome (M2SU90 group, 58 eyes). The nominal flap thickness was 110 µm for all patients and for the three devices. One month after surgery, Visante OCT was used to measure the flap thickness at 20 locations on each cornea and the results were assessed for uniformity, regularity, and accuracy.</p><p><b>RESULTS</b>At 1 month after surgery, the mean central flap thickness was (111 ± 3) µm in the IntraLase group, (114 ± 8) µm in the SBK group, and (118 ± 13) µm in the M2SU90 group respectively. The flaps in the IntraLase group and the SBK group were more regular, showing an almost planar configuration, than the meniscus-shaped flaps in the M2SU90 group. The maximum deviation from the intended flap thickness (110 µm) was 6 µm in the IntraLase group, 10 µm in the SBK group, and 20 µm in the M2SU90 group respectively. A difference greater than 20 µm was observed in 0.42% of measurements in the IntraLase group; 2.95% of the measurements in the SBK group and 21.12% of measurements in the M2SU90 group.</p><p><b>CONCLUSIONS</b>The flaps created by the IntraLase femtosecond laser and Moria One Use-Plus SBK are more uniform; more regular, and more accurate than those created by the Moria M2 Single-Use 90 µm-head microkeratome. The first two methods can make precise flaps for Sub-Bowman Keratomileusis.</p>
Subject(s)
Adolescent , Adult , Humans , Keratomileusis, Laser In Situ , Methods , Surgical Flaps , Tomography, Optical CoherenceABSTRACT
Background Lasein situ keratomileusi(LASIK) imainstream surgery forefractive correction,and femtosecond laseimuch often used to create thin corneal flap.The measuremenof OPTOVUE RTVue-100 OCto flap and stromal bed thicknesseofferuseful basifoLASIK.Ican be used in measuring the thicknesand shape of the corneal flap.Buthe study on the comparison of flap thicknesbetween WavelighFS200 femtosecond laseand MoriM2 microkeratome 90 μm-knife (Mori90 microkeratome) LASIK by OCilack.Objective The aim of thitrial wato compare the featureof corneal flapcreated by the WavelighFS200 femtosecond laseand Mori90 microkeratome.Methodpiloand prospective study wadesigned.Written informed consenwaobtained from each patienprioto LASIK.Sixty righeyeof 60 patientwith myopiomyopiastigmatism were enrolled in thiclinical trial.The patientwere randomized into the FS200 femtosecond lasegroup and Mori90 microkeratome group with matching demography.RTVue OCwaused to measure flap thicknesusing 10 settingon the 60 eye1 month afteoperation.The featureof the LASIK flapwere analyzed based on the measuring outcomes.ResultThe central flap thickneswa(112±3) μm and the mean flap thickneswa(112 ±3) μm in the FS200 femtosecond lasegroup,which wasignificanlowethan the central flap thicknesa(121±7) μm and the mean flap thicknesa(128±11) μm in the Mori90 microkeratome group respectively (P=0.031,0.030).Corneal flapin the FS200 femtosecond lasegroup showed flashape and thain the Mori90 microkeratome group wameniscushape.The central flap thickneswanoevidently differenfrom thaof peripheral thicknesin the FS200 femtosecond lasegroup (P =0.320).However,in the Mori90 microkeratome group,the central flap thickneswaobviously thinnethan thain the peripheral thicknes(P=0.038).The mean deviation between the actual and predicted flap thicknes(110 μm) wa(3±4)μm in the FS200 femtosecond lasegroup and (17±10) μm in the Mori90 microkeratome group,showing significandifference between them (P =0.009).ConclusionRTVue OCdeterminethathe shape of flapcreated by the FS200 femtosecond laseimore uniform and closeto the expected thicknesof 110 μm than the onecreated by the Mori90 microkeratome.OPTOVUE RTVue-100 OCiuseful tool to evaluate the flap shape and thicknesafteLASIK.
ABSTRACT
Objective To compare the efficacy and predictability of sphere-cylinder-combined LASIK and two-zone cross-cylinder LASIK for the correction of moderate and high astigmatism.Design Prospective,comparative case series.Participants 40 eyes of 35 patients with mixed astigmatism undergoing LASIK.Methods All patients were treated with Visx Star IV LASIK system.20 eyes of 19 cases were used for sphere-cylinder combined LASIK mode and 20 eyes of 16 cases for two-zone-cross-cylinder LASIK mode.All sub- jects were followed more than 6 months.Main Outcome Measures Uncorrected visual acuity (UCVA),best spectacle-corrected visual acuity (BSCVA),spherical diopter,residual astigmatism and corneal thickness.Results For the patients who received two-zone-cross-cylinder LASIK mode,the UCVA at 6 months after surgery was 0.5 or above,and 13 eyes (65.0%) were 1.0 or above. For the patients who received sphere-cylinder-combined LASIK mode,the UCVA at 6 months after surgery was 0.5 or above,and 11 eyes (55.0%) was 1.0 or above (P=0.683).The residual astigmatism for the patients received sphere-cylinder-combined LASIK mode was (1.15?1.00)D,while for the patients received cross-cylinder LASIK mode was (1.13?0.62)D(P=0.045).The remotion depth of cornea for sphere-cylinder-combined LASIK mode and cross-cylinder LASIK mode was (36.73?13.12)?m and (15.60?6.85)?m,respectively (P= 0.031).Condusion The UCVA,residual astigmatism and corneal thickness after surgery in two-zone-cross-cylinder LASIK mode were better than that in sphere-cylinder-combined LASIK mode for the correction of moderate and high astigmatism.