Abstract
Purpose :
To compare corneal thickness measurements from ultrasound pachymetry technology with optical coherence tomography (OCT) in tissues precut for endothelial keratoplasty
Methods :
In this prospective study, donor corneas that were suitable for Descemet stripping automated endothelial keratoplasty (DSAEK) were enrolled. Precut corneas were prepared for Descemet stripping automated endothlial keratoplasty by using standard eye bank protocol. Prior to cutting, OCT (RTVue, Optovue, Inc.) was used to measure central and midperipheral (3 mm from center) thickness of donor corneas in the storage chamber. Prior to cutting and epithelial scraping, central and four midperipheral measurements were taken of the cornea via ultrasound pachymetry (PalmScan Pachymeter, MicroMedical Devices). After dissection, the anterior lamellar cap was removed and the measurements were taken again via ultrasound and parallel measurements without the cap were taken using OCT. Differences between measurements were studied using a pairwise t-test and correlation coefficients.
Results :
The study will enroll 50 donor corneas. Preliminary baseline data of 38 corneas measured with ultrasound pachymetry showed an average central corneal thickness of 465 µm with a standard deviation of 68 µm before DSEK preparation. Preliminary results from 4 corneas showed a difference in mean central corneal thickness of 2.25 µm between ultrasound pachymetry and OCT before cutting and a difference of 8.25 µm in cut tissue. Midperipheral corneal thickness showed a difference in average thickness of 38.56 µm between OCT and ultrasound pachymetry. Central corneal measurements of DSEK tissue thickness taken via OCT were positively correlated with ultrasound measurements (r=.88), and mid-peripheral corneal measurements of DSEK tissue were also positively correlated with OCT and ultrasound (r=.19).
Conclusions :
Preliminary results suggest that OCT and ultrasound measurements of central corneal thickness are highly correlated, while measurements taken at the mid-periphery of the tissue are not well correlated. Additional donor corneas are currently being enrolled and final results and conclusions will be presented. Comparison of OCT anterior segment precut DSEK tissue analysis will be discussed.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.