Directional scrolling pattern of corneal endothelial grafts for Descemet membrane endothelial keratoplasty

Abstract

Purpose : Heterogeneous scrolling behavior of Descemet membrane endothelial keratoplasty (DMEK) grafts complicates surgery. The impact of the donor’s posterior corneal shape on scrolling is unknown. We determined whether DMEK grafts have a preferred scrolling pattern.

Methods : This prospective observational study assessed scrolling axes of DMEK grafts relative to the donor’s eye. The eye bank randomly marked the rim of corneoscleral donor buttons during trephination. Surgeons recorded the scrolling axis relative to the eye bank marking and to the normal DMEK upside-down orientation marks but remained masked to the position of the eye bank marking. The scrolling axis was categorized as vertical (0–30°), oblique (>30–60°), and horizontal (>60–90°). Using mixed-effects models, we calculated scrolling axes and 95% confidence intervals (CI).

Results : Scrolling patterns of 171 donor corneas from 129 organ donors were determined. Median donor age was 71 years (interquartile range [IQR], 64-78); 40% were women and 16% of eyes were pseudophakic. 24% of donors had diabetes mellitus type 2. The donor graft scrolled vertically in 131 eyes (77%, 95% CI 70–82), horizontally in 22 eyes (13%), and oblique to the donor’s cornea in 18 eyes (11%). Non-vertical scrolling was more common donors with diabetes (mean axis deviation from vertical, 16°, 95% CI 4–28) and potentially among male donors (mean, 10°, 95% CI 0–21).

Conclusions : DMEK grafts have a natural scrolling tendency at the vertical axis. Anticipating this tendency could potentially help improve techniques for preparing trifolded and preloaded DMEK grafts. Scrolling axes should also be assessed as a potential risk factor for incomplete graft attachment.

This is a 2020 ARVO Annual Meeting abstract.