Study of Accuracy of Corneal Flap Thickness by Using Femtosecond Laser Technology

Abstract

Background- LASIK is the most popular surgery to correct the refractive errors nowadays. It is proved to be safe, effective and well predictable. It is important to produce a uniform flap with a narrow SD from the intended thickness. The Integrated optical pachymetry is a convenient and useful feature of the EX500 excimer laser which can be used to measure flap thickness intraoperatively.Objectives: this study aimed to detect the accuracy of Allegretto Wavelight FS200™ platform in creation of different corneal flap thicknesses. Patients and Methods: sixty eyes of 30 myopic patients were included in our study, the patients were operated by 2 different surgeons from June 2017 till December 2017. The patients were distributed randomly into 3 studied groups. Group I (20 eyes with intended fs flap 100um), group II (20 eyes with intended fs flap 110um) and group III (20 eyes with intended fs flap 120um). All participants were subjected to full medical history taking, uncorrected distance visual acuity, slit-lamp microscopy, corneal topography using oculus® pentacam device, manifest and cycloplegic refraction, corrected distance visual acuity, fundus bio-microscopy examination using 90 D lens. Results: inthis study 100μm thickness group (Group A) showed the lowest difference between the mean result and the intended flap (-0.35um) followed by the 120um group (Group C) with difference of (-2.9um) between the mean result and the intended flap thickness followed by the 110μm group (group B) with the highest difference (-3.45um) from the intended flap thickness. Conclusion: the flaps made with the Wavelight FS200 femtosecond laser were predictable and uniform more predictable in group A than in group C and B, but with no statistical significance between the three studied groups (P=0.402).