Abstract
Purpose: :
To assess the accuracy and reproducibility of Fourier-domain optical coherence tomography in the measurement of central corneal flap thickness in laser in situ keratomileusis (LASIK) by using Moria M2 microkeratome.
Methods: :
Fifteen myopic patients (30 eyes), mean age 29.5 years, underwent bilateral LASIK with a superior hinged flap using the Moria M2 microkeratome (90-microm single use head). The left eye was always operated first and the right eye second, using the same blade. The central corneal flap thickness (CCFT) was measured after 1 month by the same examiner, using FD-OCT (RTVue, Optovue Inc., Fremont, CA) with anterior segment adaptor.
Results: :
The flap interface was demonstrated by FD-OCT. The mean post operative central corneal thickness(CCT) was measured as 454 +/- 30 micron by FD-OCT and 467 +/- 32 microm by ultrasound pachymetry. The mean postoperative CCFT was 123 +/- 16 micron (ranging 105 to 149 micron) and 129 +/- 18 micron (ranging 110 to 151 micron) by FD-OCT for right and left eyes, respectively.
Conclusions: :
The present data showed that FD-OCT not only provides quantitative measurement of CCT and CCFT but also presents clear images of postoperative central corneal flat. The measurement of CCT byFD-OCT with anterior segment adaptor was slightly lower than the measurement by ultrasonic pachymetry consistently. The corneal flaps by Moria M2 90-microm single use head were actually thicker than generally expected, based on FD-OCT data. This information may be critical for planning LASIK enhancements.
Keywords: cornea: stroma and keratocytes • refractive surgery: LASIK • myopia