Artemis very high-frequency digital ultrasound-guided repositioning of a free cap after laser in situ keratomileusis

Abstract

We present a patient in whom a symmetrically round free cap occurred during laser in situ keratomileusis (LASIK), and flap repositioning was performed without laser ablation. A loss of 3 lines of best spectacle-corrected visual acuity (BSCVA), monocular diplopia, and topographic irregular astigmatism confirmed that the free cap orientation was incorrect. Two subsequent free cap rotations based on refraction failed to realign the free cap into its original position. Artemis 3-dimensional very high-frequency digital ultrasound analysis found the thickness profiles of the free cap and bed to be irregular and mismatched. The rotation required for anatomic realignment was determined by digitally generating a "lock and key" superimposition of the free cap and stromal bed thickness profiles. After Artemis-guided free cap rotation, the eye regained preoperative BSCVA and symmetrical corneal topography with a +0.50 diopter change in spherical equivalent.