Comparison of healing patterns of different side-cut angulations after FS-LASIK

Aim To investigate and evaluate healing patterns around flaps made with different side-cut angulations after femtosecond laser in situ keratomileusis (FS-LASIK). Methods Thirty-four patients (68 eyes) received a 90° side-cut (n=34) or a 120° side-cut flaps (n=34) made with a femtosecond laser. One day, 1wk, 1 and 3mo postoperatively, side-cut scar was evaluated under slit-lamp photography according to a new grading system (Grade 0=transparent scar, 1=faint healing opacity, and 2=evident healing opacity). In vivo corneal confocal microscopy and anterior segment optical coherence tomography (AS-OCT) were used to observe wound-healing patterns around flap margin in the two groups. Sirius Scheimpflug Analyzer was also used to analyze higher order aberrations 3mo after surgery. Results There were no significant differences in flap wound-healing patterns at each follow up between the two groups (P>0.05). Three months after surgery, the flap edge scar classified as Grade 0 had excellent apposition and rapid nerve regeneration. At 3 mm and 5 mm pupil diameters, there were significant differences in trefoil aberrations between the two groups (P 0.05). Conclusion Flap edge scars classified as Grade 0 have excellent apposition and rapid nerve regeneration, and 120° side-cut angle flaps induce less trefoil aberrations after FS-LASIK.