Wide-Field Contact Specular Microscopy Can Reliably and Repeatedly Image the Same Corneal Endothelial Location

To assess whether slit-scanning specular microscopy (CellChek C; Konan Medical) can repeatedly image the same corneal location using anatomic landmarks (posterior corneal rings and corneal undulations) and unique cells identified during imaging.

A total of 203 eyes (113 patients) with and without corneal pathology were imaged to assess the prevalence of anatomic landmarks. A subcohort of 20 healthy eyes was used to identify unique cells adjacent to anatomic landmarks. Landmarks were then used to locate the same cells on repeat imaging approximately 1 week later. Endothelial cell density (ECD), coefficient of variation, and percent hexagonality were calculated. Intraclass correlation coefficient and 95% limits of agreement were used to measure variability and reproducibility of imaging.

Approximately 91% of eyes had either posterior corneal rings or undulations present. Undulations were more common than posterior corneal rings in both healthy and diseased corneas. Among subcohort eyes, unique cells were found adjacent to anatomic landmarks in 100% of eyes. Landmarks were used to reimage the same cells in 75% of eyes. There was minimal variation in ECD, coefficient of variation, and hexagonality; intraclass correlation coefficient and 95% confidence intervals were 0.891 [0.715-0.962], 0.612 [0.179-0.849], and 0.793 [0.499-0.925], respectively. The 95% limits of agreement for ECD was -359.9-260.98.

Landmarks identified with slit-scanning specular microscopy allowed reliable reimaging of the same endothelial location, providing a powerful tool to better understand the role of the peripheral endothelium in health and disease.