Nita G. Valikodath, MS, Meraf A. Wolle, MD, MPH, Daniel Sand MD, Lauren Johnson, MS, Maria A. Woodward MD, MS
ABSTRACT
Introduction: Descemet stripping automated endothelial
keratoplasty tissue thickness can be modified by various tissue
processing factors including microkeratome (MK) head size,
anterior chamber pressure (ACP), and cut pass duration.
Objective: Our primary objective was to evaluate how changes
in MK head size, ACP, and cut pass duration affect endothelial
cell counts and tissue thickness.
Methods: Donor corneas underwent tissue processing under various
combinations of MK head size, ACP, and cut pass duration.
Endothelial cell density (ECD) and optical coherence tomography
(OCT) were recorded both pre- and post-processing. We performed
multivariable linear regression to determine if MK head
size, ACP, and cut pass duration were associated with change in
ECD or tissue cut depth as measured by OCT.
Results: 38 corneas underwent processing. For every 50 μm
increase in MK head size, 77.32 ± 6.71 μm more anterior tissue
was cut (p < 0.0001). For every 5 mmHg increase in ACP,
15.19 ± 6.59 μm more anterior tissue was cut (p=0.03). Cut pass
duration was not associated with tissue cut depth (p=0.19). MK
head size, ACP, and cut pass duration were not associated with
changes in ECD (all p > 0.05).
Conclusions: Tissue processing parameters did not impact ECD.
MK head size and ACP did affect tissue cut depth and is likely
clinically significant.
Key Words: endothelial keratoplasty, eye bank, tissue preparation
Abbreviations: DSAEK, Descemet Stripping Automated Endothelial
Keratoplasty; MK, microkeratome; ACP, anterior chamber
pressure; ECD, endothelial cell density; OCT, optical coherence
tomography; TT, tissue thickness; DMEK, Descemet’s membrane
endothelial keratoplasty; BSS, balanced salt solution