Preloaded Donor Cornea Tissue Suitable for Endothelium-In DMEK

Preloaded donor tissue used in an endothelium-in pull-through corneal surgery has similar outcomes to procedures using surgeon-loaded tissue, according to a study published in Cornea. The study reviewed a device that facilitates the application of donor tissue in Descemet membrane endothelial keratoplasty (DMEK) while reducing the number of steps in standardized preparation.

“Performing DMEK has a steep learning curve, from donor tissue preparation to insertion and positioning, as each step requires multiple skilled maneuvers with an inherent risk of graft damage. To overcome these issues and reduce the learning curve, eye banks have started to provide prestripped, pretrephined, and preloaded tissue in both endothelium-out and endothelium-in orientations,” the researchers explain. “Prior studies have suggested that the availability of eye bank–prepared tissue would facilitate the adoption of DMEK among corneal surgeons.”

Investigators at the Johns Hopkins Wilmer Eye Institute reviewed the medical records of 163 eyes from 125 patients with Fuchs endothelial corneal dystrophy (FECD). The patients all underwent DMEK surgery, with or without cataract extraction. They were divided into 2 groups, those who underwent DMEK with surgeon-loaded tissue (n=83), and those who received a preloaded donor tissue (n=80).

Surgeons evaluated the participants’ best-corrected visual acuities (BCVA), central corneal thicknesses (CCT), endothelial cell densities, and early postoperative complications — including small and large graft detachments, graft failure, and rebubbling rates. They also noted instances of postoperative cystoid macular edema (CME) and pupillary block.

They found no significant differences between groups regarding BCVAs or CCTs in the 2-year follow-up period. The researchers also noted endothelial cell densities had no significant between-group differences 1 year following surgery. 

Although patients who underwent both DMEK and cataract extraction required significantly more rebubbling compared with those who underwent DMEK alone (21.8% vs 7.7%, P =.048), those with graft detachments who received surgeon-loaded tissue had a higher rebubbling rate compared with the preloaded donor tissue group (21.7% vs 15.0%; P =.27). In the preloaded donor tissue procedures, 1.3% of patients experienced primary graft failure, compared with 2.4% in the surgeon loaded group (P =.58).

“Preloaded DMEK tissues provide several benefits to the surgeon including standardized preparation and time savings,” the investigators report. “The use of preloaded tissue makes the procedure simpler for novice surgeons.” 

The study was limited by its retrospective design, inconsistent follow-up, and restriction to only eyes with FECD.