Abstract
Purpose:
Creating a mouse model that best represents the corneal limbal stem cells deficiency (LSCD)
Methods:
Three different methods were used to create mouse models of corneal LSCD in C57BL/6J mice (6 eyes per group). Group 1: Complete mechanical removal of corneal epithelium with a blunt scraper from limbus to limbus. Group 2: Complete mechanical corneal epithelial removal followed by heat cauterization, 360 degrees all around the limbus. Group 3: Applying 0.1% sodium hydroxide (NaOH) to the limbal area for 30 seconds using 2mm filter paper discs, after removing the whole corneal epithelium with a blunt scraper. Slit lamp examination was performed to evaluate the degree of fluorescein staining and corneal neovascularization compared to control eyes. Eyes were removed for whole mount immunostaining for Cytokeratin 12 and Cytokeratin 8.
Results:
All groups showed evidence of late fluorescein staining with neovascularization consistent with limbal stem cell deficiency. The results in group 1 showed more variability with varying degrees of staining/neovascularization and gradual recovery of corneal type epithelium by two months in some eyes. The results were less variable in group 2 with more stable pattern of LSCD over time in all eyes. Group 3 demonstrated the most severe phenotype with frequent hemorrhage and significant opacification of the corneal stroma. Long term studies with quantitative comparison is currently underway.
Conclusions:
Mechanical corneal epithelial removal in combination with thermal injury (group 2) provides a more reproducible method (compared to mechanical removal alone) and a less destructive method (compared to alkali injury) for developing corneal LSCD in mice.
Keywords: 721 stem cells •
482 cornea: epithelium