Abstract
Purpose :
Non-invasive in vivo imaging of the cornea with cellular-level resolution offers the possibility of not only advancing our understanding of disease mechanisms through longitudinal evaluations of transgenic mouse models but also monitoring disease progression and treatment efficacy in humans. In this work, we demonstrated the capabilities of a multimodality optical imaging system to evaluate gene expression and associated structural remodeling in the cornea of transgenic mice, as well as a human imaging prototype for cellular-level corneal imaging
Methods :
An integrated system of optical coherence microscopy (OCM) and dual-channel fluorescence microscopy (DCFM) was developed to simultaneously co-register reflectance and fluorescence from the cornea of three transgenic mice, KeraRT; tet-O-Cre; RosamTmG, expressing red tdTomato in the whole body and exclusively enhanced green fluorescent proteins (EGFP) in corneal keratocytes upon doxycycline (dox) treatment. A prototype of OCM, HOCM, for human corneal imaging, was also evaluated
Results :
The integrated OCM+DCFM achieved the concurrent co-registration of reflectance and fluorescence at the line rate of 245 kHz, a lateral resolution of 2.1 um, and axial resolutions of 2.4 um, 16.3 um, and 14.4 um for the OCM, DCFM’s green channel, and DCFM's red channel, respectively, in the cornea of sacrificed mice. Figure 1 presents the images of the cornea of the three mice after dox treatment for 0, 9, and 47 days. The first mouse without dox treatment (Figs. 1(a)-1(d)) showed only a red signal from tdTomato with no EGFP expression as expected, except for a cellular feature that was presumed to be a Langerhans cell (Fig. 1(c)). The EGFP activation was effective in corneal keratocytes of the two mice treated with dox chow for 9 and 47 days (Figs. 1(e)-1(l)). Figure 2 presents HOCM in vivo images of human corneal basal epithelial cells, corneal nerves, corneal keratocytes, as well as corneal endothelial cells
Conclusions :
The integrated OCM+DCFM system will be used to investigate the role of transforming growth factor beta type 2 signaling pathways in corneal homeostasis and pathophysiology. The HOCM will be used to evaluate corneal epithelial and endothelial cells, as well as corneal nerves and keratocytes in several corneal diseases
This abstract was presented at the 2023 ARVO Imaging in the Eye Conference, held in New Orleans, LA, April 21-22, 2023.