Reproducibility of laser in?situ keratomileusis flap thickness using a new multifunctional femtosecond laser platform and?correlation with clinical preoperative measurements

摘要

PurposeTo analyze the reproducibility of laser in?situ keratomileusis (LASIK) flap thickness (target 120?μm) using the multifunctional femtosecond laser (Lensx) and correlate postsurgical measurements with preoperative factors. SettingHospital Oftalmológico Vis?o Laser, Santos, S?o Paulo, Brazil. DesignProspective case series. MethodsPatients with stable refraction for over a year were evaluated. Patients who submitted to refractive surgery with ?1.25 to ?6.00 diopters (D), with or without astigmatism up to ?4.00 D, and corneal curvature of 40.00 to 47.00 D were included. At 100?days postoperatively, an independent examiner performed 4 high-resolution tomographic sections of the cornea for each eye at 45- to 225-degree, 90- to 270-degree, 135- to 315-degree, and 0- to 180-degree meridians. Two masked experienced observers analyzed each section using measuring points located at the center of the cornea (0.0?mm), 2.0?mm to the left and to the right of the center, and 4.0?mm to the left and to the right of the center. ResultsThe study comprised 33 patients (63 eyes), aged 21 to 50?years. A significant difference from the target flap thickness (120?μm) was found in 2 of 20 measurements; however, the actual difference was approximately 2.2?μm. Interrater reliability was excellent (ICC?>?0.75), with an interrater bias close to 0. Clinical measurements were not predictive of the set of 20 postoperative measurements. ConclusionReproducibility of the multifunctional femtosecond laser was good for LASIK flap creation and no predictive correlation was found with preoperative clinical factors.