The effect of corneal flap on optical aberrations

Clinical outcomes of optimized prolate ablation and custom aspheric treatment in laser-assisted subepithelial keratectomy

“…Other studies [4][5][6][7] report that the correction of high myopia is associated with increased HOAs and that creating a flap leads to more corneal HOAs because of the induced irregular stromal bed and misalignment of the flap after laser in situ keratomileusis. [8][9][10][11] Increased HOAs postoperatively have been associated with decreased visual performance under mesopic and low-contrast conditions. 2,12,13 In addition, it has been shown that there is a correlation between ocular aberrations and visual symptoms, such as coma with monocular diplopia and spherical aberration with starburst and glare.…”

Factors affecting the change in lower-order and higher-order aberrations after wavefront-guided laser in situ keratomileusis for myopia with the Zyoptix 3.1 system

“…2,3 The microkeratome cut is also responsible for a small amount of induced HOAs after LASIK. [10][11][12][13] Thus, the change in the wavefront error after wg-LASIK, and therefore the predictability of the correction of LOAs and HOAs, is a result of the interaction of several factors. Since no study has investigated the effects and interaction of all these factors simultaneously, the present study was undertaken to identify the factors that affect the change in LOAs and HOAs after wg-LASIK for myopia.…”

The future role of wavefront-guided excimer ablation

“…Flap creation -Besides excimer ablation, cutting of a LASIK flap itself induces changes in low-order aberrations and HOA, although flap-induced aberrations only play a marginal role compared to those induced by the ablation [39,43,56]. Preoperative aberrometer measurements are made before flap creation, changes that occur after this step cannot be included into the laser algorithm.…”