The influence of speed during stripping in Descemet Membrane Endothelial Keratoplasty tissue preparation.

Abstract

Purpose : Descemet membrane endothelial keratoplasty (DMEK), when compared to the other techniques of endothelial keratoplasty, provides a faster visual rehabilitation and a lower risk of graft rejection. During DMEK surgery, the graft conformation and particularly scroll width has a crucial role in its unfolding within the anterior chamber. We note that Descemet membrane contains elastin and its elastic properties may contribute to the scrolling characteristics of the graft after stripping<font size="1">. </font>We postulate that this may be influenced by the speed of stripping of the Descemet’s from the stroma during DMEK graft preparation secondary to the effect and duration of tension on the elastic recoil of the tissue. To our knowledge, no studies have been performed to investigate the effect of the stripping speed on the scrolling behaviour and final graft scroll width resulting in preparation for subsequent DMEK. Tha aim of thre study is evaluate if the speed of stripping a DMEK graft influences the graft scroll width.

Methods : Human corneas suitable for research were selected for the study. Pairs of corneas were randomly divided into 2 groups. 1 cornea was stripped with a slow speed (Group 1) and the contralateral with a fast speed (Group 2). Slow speed was defined as total time greater than 150 seconds or speed <0.057mm/sec. Fast peeling was defined less than 75 seconds or speed >0.11mm/sec. The grafts acquired were evaluated by microscopy for the graft scroll width and endothelial cell density (ECD) change pre and post preparation.

Results : 10 corneas of 5 donors were included in the analysis. The mean donor age was 70.6±6.4 years. The mean total time of the tissue preparation in group 1 was 274.2±37 seconds, and in group 2 was 153±53 seconds (p-value=0.0038). The mean speed of stripping in group 1 was 0.048±0.006 mm/sec, in group 2 was 0.188±0.063 mm/sec (p-value = 0.0055). The graft width in group 1 was 6.28±0.92 mm and in group 2 was 2.92±0.23 mm (p-value = 0.00066). The mean endothelial cell loss in group 1 was 292±109 cells/mm² and in group 2 was 160±23.66 cells/mm² (p-value=0.039).

Conclusions : We found a correlation between the speed of stripping, scroll width and endothelial cell loss. Slow peeled DMEK grafts result in a wider scroll width but were associated with a greater reduction in ECD.

This is a 2020 ARVO Annual Meeting abstract.