Posterior corneal surface changes after refractive surgery

The change in internal aberrations following myopic corneal laser refractive surgery

“…A change may occur to the posterior cornea [21,22], which is supported by slit-scanning topography studies indicating changes occur to the posterior cornea following LASIK [24][25][26][27][28][29][30][31][32][33][34][35][36]. However, some slit-scanning topography studies have found no changes to the posterior cornea post-LASIK [37,38], and Ueda et al [39] demonstrated that these posterior corneal changes are artefacts due to changes in the magnification ratio. This is further supported by Scheimpflug imaging studies demonstrating no posterior corneal changes following LASIK [40,41].…”

Corneal changes after laser refractive surgery for myopia: Comparison of Orbscan II and Pentacam findings

“…However, different types of laser refractive surgery have been reported to induce a forward shift of the cornea, and their effect on the posterior cornea has been of great concern. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Although several instruments are routinely used to examine the cornea in terms of thickness and topography, few are capable of posterior corneal evaluation. One of the first noncontact devices in this category, the Orbscan (Bausch & Lomb), is a slit-scanning topography system.…”

“…One of the first noncontact devices in this category, the Orbscan (Bausch & Lomb), is a slit-scanning topography system. 5,10,15,16 A single acquisition provides users with data and color maps of corneal thickness, anterior and posterior curvatures, and elevation. Most published reports of posterior changes of the cornea are based on Orbscan measurements of posterior elevation and posterior curvature.…”

Ectasia after laser in situ keratomileusis

“…In other words, does the Removal of an Excessive Percentage of the Preoperative incidence of enhancement surgery increase with decreasCorneal Thickness ing RST? There is unsupported evidence that the posteRemoving 18% of the corneal thickness in a 550 m rior cornea stroma bows forward after LASIK, 40,44,[63][64][65][66] cornea (99 m) probably has less of a structural-weakenbut 1 report did not document differences in outcomes ing effect than removing 18% in a 475 m cornea between eyes with an RST less than 250 m and eyes with thicker residual stromal measurements. 64 The astigmatism being corrected is not a likely corneal tissue removed could be calculated based on factor in increasing the risk for ectasia.…”