Cumulative Endothelial Cell Loss in Descemet Membrane Endothelial Keratoplasty Grafts From Preparation Through...

Evaluation of cumulative Descemet membrane endothelial keratoplasty endothelial cell loss (ECL) from preparation through injection using 2 different glass injectors.

Eighteen Descemet membrane endothelial keratoplasty grafts with "S" stamps were prepared by eye bank technicians. Nine grafts were assigned to injection with a modified glass Jones tube injector with a 2.4-mm opening and 9 were assigned to injection with the DORC glass pipette injector (<1.5-mm opening). The grafts were prepared and loaded into the injectors using the standard surgical technique, ejected onto a bed of viscoelastic on a glass slide, and unscrolled using viscoelastic. The grafts were stained with the vital dye Calcein-AM, then digitally imaged and analyzed using FIJI. The percentage of ECL was calculated by measuring the area of nonfluorescent pixels and dividing it by the total graft area pixels. A statistical comparison was performed using a 2-tailed unpaired t test.

Grafts injected using the DORC injector versus Jones tube injector had ECL of 29.2% ± 8.5% [95% confidence interval (CI)] versus 23.0% ± 5.1% (95% CI), respectively. This difference was not statistically significant (P = 0.17); however, the patterns of ECL on the grafts was different between injectors. Peripheral ECL caused by trephination and surgeon grasp sites accounted for 7.5% ± 1.2% (95% CI).

There was no statistical difference in ECL between the 2 injectors. There were characteristic differences in patterns of ECL seen between injectors, which may be clinically relevant and indicate the types of stress that grafts are exposed to during passage through various injectors.