The Use Of Novel Injectable Tri-Folded Endothelium-In Dmek In Cases Of Complex Anterior Chambers

Traditionally DMEK (Descemet’s Membrane Endothelial Keratoplasty) is not performed in eyes where it is difficult or not possible to manipulate the depth of the anterior chamber. A novel technique and device is used for delivering a correctly oriented preloaded DMEK graft into the anterior chamber (AC) without direct or indirect manipulation in patients with vitrectomies, failed penetrating keratoplasty (PKP) and glaucoma shunts.

All patients were reviewed at an eye clinic in Cape Town, South Africa and surgeries were performed at a private eye hospital.

All grafts (n=7) were prepared at the Lions World Vision Institute eye bank (Tampa, USA) with a novel hydro separation “BLISTER” method, "S" marked, stained, folded into a tri-folded configuration with inverted endothelium, and loaded into a novel glass cannula before being shipped to South Africa. Graft transit time to surgery was 4 days. Out of 7 patients – 5 had failed PKP, 1 received an anterior vitrectomy during the DMEK procedure and 1 patient had 2 glaucoma shunts in the anterior chamber. The size of the main incision, number of sutures used, average time to correct graft unfolding, regression of corneal thickness and post-operative endothelial cell densities were assessed.

Surgeries were performed the day after graft arrival. The incision was 3.0-3.2 mm. All grafts were delivered and unfolded independently into the anterior chamber through fluid insertion and were correctly orientated. 3-5 stitches were required to close the wound. The mean time from the graft entering the AC to complete unfolding was approximately 37 seconds. All grafts were immediately correctly orientated. Mean central corneal thickness reduced by 225.3µm (29.83%) All grafts cleared within 4 weeks post-transplant with 2 successful graft-re-bubbling required. Mean 1 month post-operative visual acuity improved to 0.5 (decimal) from 0.3 before surgery. Mean endothelial cell density at 1 month post-operative was 2064. 

A novel glass carrier allows secure storage of preloaded DMEK grafts with endothelium folded in and delivered the grafts by fluid insertion into the AC in the correct anatomical orientation with immediate streamlined unfolding. This novel technique enabled DMEK to be performed in complex cases of deep anterior chambers, such as seen in failed PKP and vitrectomized eyes, as well as in the presence of glaucoma shunts. Unfolding of the DMEK graft has become much more predictable and quicker in complicated anterior chambers.