DMEK Graft Preparation Difficulties Do Not Affect Visual Outcomes, Rebubbling

Descemet membrane endothelial keratoplasty (DMEK) graft preparation difficulty has no significant effect on 1-year postoperative clinical outcomes in patients, according to research published in Cornea.

Researchers at a high-volume DMEK surgery center conducted a retrospective study to quantify DMEK graft preparation difficulties and complications and to evaluate their effects on clinical outcome. 

They leveraged data on consecutive DMEK surgeries for corneal endothelial disorders from the prospective Cologne DMEK database. The surgeries were conducted by 3 surgeons and took place between July 2018 and December 2019. 

Based on preparation conditions, surgeons were asked to rate the difficulty of the DMEK graft preparation as easy, difficult, and very difficult. The researchers evaluated and compared postoperative best spectacle-corrected visual acuity (BSCVA) and endothelial cell count (ECC) at 3, 6, and 12 months and rebubbling rates at 12 months between groups.

The study included 214 patients (63.8% women and 36.2% men), with a mean age of 68.2±12.7 years. The main indication for DMEK surgery was Fuchs endothelial corneal dystrophy (96.7%). The surgeons rated the DMEK graft preparations as easy in 41.6% of cases (group 1, n=89), difficult in 30.8% (group 2, n=66), and very difficult in 27.6% (group 3, n=59). The mean follow-up duration after DMEK surgery was 14.9±7.2 months. 

The researchers found no significant difference between the easy, difficult, and very-difficult preparation groups for mean BSCVA at 3 months (0.19 vs 0.16 vs 0.22 logMAR; P =.179, 6 months (0.15 vs 0.12 vs 0.13 logMAR; P =.325), and 12 months (0.09 vs 0.09 vs 0.08; P =.682, respectively). They did not observed a significant difference between the easy, difficult, and very-difficult preparation groups for mean ECC at 3 months (1532 vs 1640 vs 1264 cells/mm²; P =.537) and 6 months (1604 vs 1453 vs 1489 cells/mm²; P =.606) but did note a significant difference at 12 months (1530 vs 1574 vs 1105 cells/mm²; P =.045, respectively). 

The team found no significant difference in 12-month rebubbling rate among the easy, difficult, and very-difficult preparation groups (17.9% vs 25.7% vs 23.7%; P =.585). 

“In conclusion, our data show that difficult or very difficult preparation conditions of the DMEK graft do not lead to any worsening of visual acuity or rebubbling rate in the 1-year outcome compared with an easy preparation of the DMEK graft. In the case of very difficult preparation of the DMEK graft, the [endothelial cell density] at 12 months showed slightly poorer results,” the researchers report.

Limitations of the study included its retrospective nature and potential unknown effects of donor factors on the preparation.