In vivo imaging of corneal nerves and cellular structures in mice with Gabor-domain optical coherence microscopy

Abstract

Purpose : We investigate the feasibility of non-contact imaging of mice corneas with Gabor-Domain Optical Coherence Microscopy (GDOCM) to resolve endothelial cells and corneal nerves in vivo.

Methods : In vivo GDOCM imaging was conducted on six healthy and six hyperglycemic C57BL/6J mice. Hyperglycemic mice were induced with a single intraperitoneal injection of streptozotocin at 150 mg/kg or rendered hyperglycemic by nature of misfolded insulin (Ins2akita/J mouse). Three-dimensional (3D) images of mice corneas over a field of view of 1 mm² were collected in contact and non-contact configurations. An intensity-based registration using rigid body transformations was used to perform motion correction via the StackReg plug-in for ImageJ. Cellular resolution was achieved in the 3D images. Corneal nerve fibers were traced and their lengths and branches calculated using the Simple Neurite Tracer plug-in in ImageJ.

Results : In vivo corneal imaging with cellular resolution and differentiation over a field of view of 1 x 1 x 0.2 mm² was demonstrated. Motion correction removed biological movement attributed to heart and respiration rate to allow recovery of cellular features in both contact and non-contact imaging modalities. Endothelial and epithelial cells showed mosaic patterns in both healthy and diabetic animals. Corneal nerves showed reductions in average nerve fiber length and in nerve branching points in diabetic mice consistent with ex vivo reports.

Conclusions : In vivo corneal imaging was conducted for the first time with GDOCM on normal and diabetic mice, with both non-contact and contact imaging modalities. The non-contact approach provides a volumetric field that enables quantification of key cellular features of the healthy and diabetic eye. This label-free approach may provide additional information in the clinical setting regarding the changes within disease populations or same eyes over time.

This is a 2020 ARVO Annual Meeting abstract.

 

a) 3D rendering of a mouse cornea imaged in vivo with GDOCM over a field of view of 1 mm². En face view of basal epithelial cells (b) and endothelial cells (c). Bar is 0.1 mm. Sub-cellular structures thought to be primary cilia are visible (dark spots in the endothelial cells).

 

Mouse corneas imaged in vivo with GDOCM. 1 mm²en face views using non-contact (a) and contact (b) imaging, averaged over a depth of 6-13 mm, with corneal nerves (arrows) visible after motion correction. The bar is 0.1 mm.