Evaluation of corneal flap thickness in relation to central corneal thickness after laser assisted in situ keratomileusis using two types of micro keratomes

Background: The most common refractive surgical surgery for the treatment of myopia, hyperopia, and astigmatism is laser assisted in situ keratomileusis (LASIK). A very important step in LASIK surgery is the formation of the flap. The corneal flap was made using a variety of microkeratomes. The purpose of this study was to compare the central corneal thickness following LASIK to the corneal thickness of the flap. Methods: This retrospective comparative study was performed on 200 eyeballs divided into four groups each of 50 eyeballs according to the type of microkeratome used for surgery; group 1 (M2 90), group 2 (M2 130), group 3 (SBK 90), group 4 (SBK 130). Cases were operated during the last seven years by ALCON WAVELIGHT EX500 unit (year of production: 2012). Results: Two hundred eyeballs of 100 patients were treated. Mean thickness of the flap of 103.3±9.54 mm, 126.05±17.07 mm, 120.9±14.4 mm, and 141.19±11.63 mm The SBK head created the thinnest flaps in the first cut utilising the SBK 90, SBK 130, M2 90, and M2 130 heads, respectively. The SBK 90 head produced the most exact and precise thickness of the flap, followed by the SBK 130 head, the M2 90 head, and the M2 130 head, as shown by the standard deviation and difference from the desired value. Conclusions: Of the 4 types, the SBK generally produced the thinnest and most accurate flaps.