Heads up Descemet membrane endothelial keratoplasty performed using a 3D visualization system

Abstract

A 68-year-old female underwent Descemet membrane endothelial keratoplasty (DMEK) in her right eye using a 3D visualization system with the surgeon looking directly to a digital screen instead of through the eyepieces of the surgical microscope. The procedure was uneventful. Five weeks after the surgery the DMEK graft was in good position and totally adhered, the cornea clear and uncorrected distance visual acuity 20/50. This is the first reported case of DMEK using 3D augmented reality visualization system. It seems to offer advantages for the corneal surgeon in critical steps of the endothelial grafting procedure.

Figure 1:

Corneal edema in the right eye as seen before the corneal transplantation (A–C). Some subepithelial fibrotic changes were visible affecting from the periphery to the paracentral area (A and C, white arrows). The visual axis was free of fibrosis (B). Five weeks after excision of subepithelial fibrotic tissue and DMEK, the cornea regained its transparency (D).

Figure 2:

The 3D visualization system's High Dynamic Range (HDR) was attached to the microscope in place of the eyepieces of the surgeon (A, yellow arrow). The surgeon adjusted the zoom and focus directly looking at the screen in front of him, and proceeded to perform surgical maneuvers in that ‘head-up’ position (B). Both the surgeon and the assistant surgeon wore 3D glasses with each lens polarized to make them see a different image through each eye, by filtering out incident light waves at certain angles (one the horizontal and the other the vertical ones), thus enhancing the stereoscopic effect (C).

Figure 3:

(A) Donor tissue preparation: the double scroll is being aspirated into the injection device. (B) Descemetorhexis. (C) Unfolding of the Descemet graft inside the anterior chamber, with the hinge facing down as confirmed by the Moutsouris' sign. (D) Separation of the scrolls by gentle taps onto the outer cornea. (E) The DMEK roll is almost completely unfolded. (F) The step is completed injecting an air bubble. The images in the screen are not crystal clear since it is necessary to wear the 3D polarized glasses to see them perfectly defined.

Figure 4:

(A) Anterior segment OCT taken the first postoperative day showed that the DMEK endothelial graft was well attached and a central corneal thickness of 547 µ. (B and C) Five weeks later the corneal thickness diminished to between 463 and 475 µ.