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.
ABSTRACT
<p><b>BACKGROUND</b>Copernicus optical coherence tomography (SOCT) is a new, ultra high-speed and high-resolution instrument available for clinical evaluation of optic nerve. The purpose of the study was to compare the agreements between SOCT and Heidelberg retinal tomography (HRT).</p><p><b>METHODS</b>A total of 44 healthy normal volunteers were recruited in this study. One eye in each subject was selected randomly. Agreement between SOCT and HRT-3 in measuring optic disc area was assessed using Bland-Altman plots. Relationships between measurements of optic nerve head parameter obtained by SOCT and HRT-3 were assessed by Pearson correlation.</p><p><b>RESULTS</b>There was no significant difference in the average cup area (0.306 vs. 0.355 mm, P = 0.766), cup volume (0.158 vs. 0.130 mm, P = 0.106) and cup/disc ration (0.394 vs. 0.349 mm, P = 0.576) measured by the two instruments. However, other optic disc parameters from SOCT were significantly lower compared with HRT-3. The Bland-Altman plot revealed good agreement of cup area and cup volume measured by SOCT and HRT-3. Bad agreement of disc area, rim area, rim volume and cup/disc ratio were found between SOCT and HRT-3. The highest correlations between the two instruments were observed for cup area (r(2) = 0.783, P = 0.000) and cup/disc ratio (r(2) = 0.669, P = 0.000), whereas the lowest correlation was observed for disc area (r(2) = 0.100, P = 0.037), rim area (r(2) = 0.275, P = 0.000), cup volume (r(2) = 0.005, P = 0.391) and rim volume (r(2) = 0.021, P = 0.346).</p><p><b>CONCLUSIONS</b>There were poor agreements between SOCT and HRT-3 for measurement of optic nerve parameters except cup area and cup volume. Measurement results of the two instruments are not interchangeable.</p>