Comparison of Ultrasound and Optical Coherence Tomography in Measurement of Pre-cut and Post-cut Descemet’s Stripping Endothelial Keratoplasty Tissue

Authors

Abigail Gordon BA, Abhinav Golla BS, Li Wang MD, PhD, Mitchell P. Weikert MD, Sumitra S. Khandelwal MD

Keywords

Descemet Stripping Automated Endothelial Keratoplasty, Cornea Transplantation, OCT, optical coherence tomography, ultrasonic pachymetry

Abstract

Purpose: The purpose of this study is to evaluate corneal thickness
using ultrasound pachymetry technology (US) in comparison
to optical coherence tomography (OCT) in tissues pre resection for
descemet stripping automated endothelial keratoplasty (DSAEK)

Methods: 30 donor corneas that were suitable for DSAEK
were enrolled in this prospective study. All precut corneas were
prepared for DSAEK using standard eye bank protocol. Prior
to cutting and epithelial scraping, central and midperipheral (3
mm from center) thickness of donor corneas were measured via
ultrasound pachymetry and OCT. Of these 30 corneas, 15 were
also analyzed for post resection thickness. The anterior lamellar
cap was removed and the measurements were taken again via
ultrasound and parallel measurements were taken using OCT
after 1.5 hours. Differences between measurements were studied
using t-test and correlation coefficients.

Results: Both OCT and US provide similar central thickness of
tissue pre resection (difference of -9 μm +/- 55 μm, P= 0.39) and
post resection (difference of 5 μm +/- 59 μm, P= 0.75). However,
while there was no difference in the post resection tissue midperipheral
thickness between the two devices (difference of -15
+/- 52 μm, P= 0.28), there was a statistically significant in the
pre resection midperipheral thickness (difference of -145 +/- 88
μm, P < 0.01).

Conclusion: OCT and US produce similar measurements for
central thickness in both pre resection and post resection lenticules.
However, while the post resection midperipheral thickness
is similar between the two modalities, there is some variation in
the pre resection thickness of the mid-periphery.