Stephen C Kaufman, MD, PhD; Natalia Kramarevsky, MD; Alessandro Meduri, MD
Descemet-stripping automated endothelial keratoplasty (DSAEK), endothelial keratoplasty, microkeratome cut time, pachymetry
ABSTRACT
Purpose: To evaluate the effect of the time used to pass the
microkeratome through the cornea during the production of
a DSAEK graft on the thickness of the posterior lamellar corneal
graft.
Methods: Twelve human corneoscleral discs were used to evaluate
the effect of microkeratome (Moria CB, Antony, France) cut
time on post-sectioned corneal lamellar thicknesses. Sectioning
was completed using a microkeratome equipped with three
microkeratome head sizes (250, 300, and 350 μm) utilizing two
different cut times (1 or 6 seconds). Eye bank excised corneas
with scleral rims were mounted on a Moria artificial anterior
chamber and the intrachamber pressure was increased to >90
mmHg. The Moria DSAEK microkeratome was used to prepare
the posterior lamellar graft tissue. Pachymetry was performed
before and after construction of the graft tissue.
Results: All corneas sectioned over a 1 second period produced
thicker residual stromal beds compared with 6 second sectioning
times. The difference between the mean residual stromal bed
thickness for all head sizes was 37 ± 50 μm thicker than intended
for 1 second cuts and 41 ± 32 μm thinner than intended for
6 second cuts (P = 0.01). The longer pass always resulted in a
thicker corneal flap. The mean total difference in corneal flap
thickness between a 1 second cut time and a 6 second cut time
for all 3 microkeratome head (250, 300 and 350 μm) sizes was
77.7 μm.
Conclusions: This pilot study provides proof of principle that
microkeratome cut time (transit time) is an important variable,
which affects graft thickness, in endothelial keratoplasty graft
preparation.