In vivo confocal microscopy of the normal equine cornea and limbus.

This research article discusses a study conducted to understand the morphological features, pachymetry (thickness of corneal layers), and endothelial cell density in the cornea and limbus (the border area where the cornea and sclera meet) of a healthy horse’s eye using in vivo confocal microscopy. The study provides a non-invasive way to examine the normal equine corneal structure at the cellular level and it also has wide-ranging diagnostic, clinical, and research applications.

Methodology

• The research involved ten horses which didn’t have any pre-existing ocular diseases.
• A modified Heidelberg Retina Tomograph II and Rostock Cornea Module were used for the examination of the central and peripheral corneas.
• Both automated and manual image acquisition modes were utilized during the examination.
• Various corneal layers’ thickness measurements were taken and endothelial cell density was determined.

Results

• The study successfully captured images of different elements of the corneal epithelium, stroma, endothelium, and limbus in all the horses.
• Particular features such as cornea’s stromal nerves, subepithelial nerve plexus, and sub-basal nerve plexus were visualized.
• Cells with characteristics similar to Langerhans cells and corneal stromal dendritic cells were constantly detected in the corneal basal epithelium and anterior stroma, respectively.
• The researchers were able to measure the median central total corneal thickness, median central corneal epithelial thickness, and median central endothelial cell density accurately.

Conclusions

• In vivo corneal confocal microscopy was identified as a precise and non-invasive method to understand the structure of a normal equine cornea at the cellular level.
• It was an efficient method for corneal sublayer pachymetry (thickness measurement) and cell density measurements.
• Through this method, a stable population of cells resembling Langerhans cells and corneal stromal dendritic cells were identified in the normal equine cornea.
• The techniques described in the study can be used for diagnostic evaluation of corneal changes associated with disease. This information has broad clinical and research applications in the horse.