Comparison of Sub-Bowman Keratoplasty Laser In situ Keratomileusis Flap Properties between Microkeratome and Femtosecond Laser.

BACKGROUND: Since thin and high-quality flaps produce more satisfactory surgical outcomes, flaps created by mechanical microkeratomes are more economical as compared with femtosecond lasers, and no Iranian study has concentrated laser in situ keratomileusis (LASIK) flap peculiarities between Moria Sub-Bowman keratoplasty (SBK) microkeratomes and LDV femtoseconds, the present study compares and contrasts them.

MATERIALS AND METHODS: This cross-sectional study was done on all patients who underwent LASIK surgery 1-month before this study. Thirty eyes were divided into per group. Flaps in the first group and second group were created, respectively, using Moria SBK microkeratome and LDV femtosecond laser. The other stages of LASIK were done equally in both groups. One month after surgery, the thickness of flaps was measured by anterior segment optical coherence tomography in five regions of flaps. Corneal anterior density was calculated and recorded 1-month after surgery using pentacam and by employing optical densitometry in a distance in the limit range of 0-6 mm from cornea center. Densitometry measurements were obtained and expressed in standardized grayscale units (GSUs).

RESULTS: Postsurgery densitometry results reveal that anterior densities of cornea in limit range of 0-2 mm in groups of LDV femtosecond laser and Moria microkeratome are 21.35 ± 0.87 GSU and 22.85 ± 1.25 GSU, respectively. Accordingly, these two groups are significantly different in this regard ( P < 0.001). Moreover, anterior densities of the cornea in the limit range of 2-6 mm in these groups are 19.66 ± 0.99 GSU and 20.73 ± 1.24 GSU, respectively. Accordingly, these two groups are significantly different in this regard ( P = 0.04). There is a lower mean of flap thickness in the case of LDV femtosecond laser.

CONCLUSION: Femtosecond laser method is greatly preferred as compared with Moria microkeratome because of greater homogeneity in flap thickness, smaller thickness, and lower density in optical zone.