Vertical Scrolling Axis Of Corneal Endothelial Grafts For Descemet Membrane Endothelial Keratoplasty

Purpose: Heterogeneity in scrolling behavior of Descemet membrane endothelial keratoplasty (DMEK) grafts complicates DMEK surgery. This prospective observational study assessed scrolling axes of DMEK grafts relative to the donor's eye. Methods: The eye bank randomly marked the rim of corneoscleral donor buttons during trephination and recorded the position relative to the donor's axis. Surgeons were masked to the absolute position of the eye bank marking and recorded the scrolling axis relative to the eye bank marking and DMEK upside-down orientation. The scrolling axis was categorized as vertical (0 to 30 degrees and 150 to 180 degrees), oblique (>30 to 60 degrees and 120 to <150 degrees), and horizontal (>60 to <120 degrees). Scrolling patterns of corneas from the same donor were assessed. Results: Scrolling patterns of 202 donor corneas from 149 donors were determined. The donor graft scrolled predominantly vertically to the donor's cornea [75%; 95% confidence interval (CI), 68%-80%]. Horizontal axes (11%) and oblique axes (14%) were less common. The median deviation in scrolling axes after unfolding the grafts was 0 degrees from the original scrolling axis (interquartile range, 0-15), indicating that scrolling axes were stable. Fellow eyes of 46 donors had 3.55 times higher odds of a nonvertical scrolling pattern if the first eye had a nonvertical scrolling pattern (95% CI, 1.37-9.20), suggesting that donor factors influencing both eyes could contribute to scrolling patterns. Conclusions: DMEK grafts have a natural and stable scrolling tendency at vertical axis of donor's cornea. Anticipating scrolling axes might help improve preparation techniques for DMEK grafts and outcomes.