Visual Outcomes after Topography-Guided Femtosecond LASIK in Virgin Eyes

Abstract

ASIK has become the most popular corneal refractive surgery. One of the critical steps in this procedure is the creation of the corneal flap (Kurtz et al., 1997). Femtosecond laser technology enables the creation of geometrically precise LASIK flaps with uniform thickness across the flap, predictable hinge lengths with lamellar dissection under the hinge and steep side-cuts for improved flap realignment (Salomao and Wilson, 2010). Customization of the ablation pattern by utilizing topography data has been reported to provide excellent refractive data with regard to UCVA and BCVA (Kanellopoulos, 2016). The important laser input data comes from the Topolyzer Vario, which employs 44 edges and 22,000 data points. In addition to data on corneal curvature, it detects the pupil and the corneal apex. It also takes an infrared image of the iris that is available to the EX500 excimer laser for exact registration of the input data to the exact spot on the cornea to be treated (Jerry, 2017).