Comparison of corneal thickness measurements after Descemet stripping automated endothelial keratoplasty between anterior segment optical coherence tomography and scheimpflug imaging systems

Pawan Prasher MD,^1,2 Orkun Muftuoglu MD,² V. Vinod Mootha MD.²

¹Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, India;
²University of Texas Southwestern Medical Center at Dallas, Texas, USA.

Purpose: Corneal thickness is one of the important parameters that undergo significant variation after Descemet stripping automated endothelial keratoplasty (DSAEK) surgery; thus, its accurate measurement is very important in understanding the post-surgical changes in cornea. Reported herein, is the comparison of corneal thickness measurements after DSAEK using Visante (Carl Zeiss Meditec, Dublin, California, USA) anterior segment optical coherence tomography (AS-OCT) and Pentacam scheimpflug Imaging System (Pentacam, Wetzlar, Germany).

Methods: Thirty eyes of 27 patients who underwent successful DSAEK surgery for corneal edema secondary to endothelial dysfunction were included in the study. Imaging was carried out by both AS-OCT and Pentacam after six months postoperatively. The measurements in central 2, 4 and 6mm zones were compared between the two instruments.

Results: The mean corneal thickness was 632.75 ± 77.23µm and 640.13 ± 59.86µm in central 2mm zone, 678.5± 72.29µm and 695.37±71.99µm in 4mm zone, and 748.63±73.55µm and 774.12±76.93µm in 6mm zone by AS-OCT and Pentacam respectively. There was no statistically significant difference between the two groups in all the zones (p>0.05).

Summary: Both AS-OCT and Pentacam provide fairly identical measurements of corneal thickness after DSAEK. Although Pentacam measurements were marginally higher than AS-OCT in all the zones, the difference was not found to be statistically significant.