Measurement and comparison of corneal flap thickness between Wavelight FS200 femtosecond laser and Moria 90 microkeratome LASIK by OCT

Abstract

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. Key words: Fourier-domain optical coherence tomography; Femtosecond laser; Cornea; Refractive surgery; Laser in situ keratomileusis; Flap thickness