Corneal abnormalities in the NC/Nga mouse: an atopic dermatitis model.

PURPOSE: To study corneal abnormalities in the NC/Nga mouse, which is an animal model of atopic dermatitis.

METHODS

To study histopathologic changes of the eyelid, conjunctiva, and cornea, we extracted the eyeballs together with upper and lower eyelids and fixed them for examination by light and electron microscopy or snap-froze them for immunohistochemistry. Transferase mediated-dUTP digoxigenin nick-end labeling staining was performed to detect apoptotic cells. In order to assess eye scratching behavior and the effect of tacroliums hydrate ointment, we made video recordings.

RESULTS

Mice kept in a conventional room suffered from various grades of blepharoconjunctivitis and scratched their eyes furiously. Tacrolimus hydrate ointment reduced their eye-scratching behavior. Histopathologic study of the eyelid and conjunctiva showed that this blepharoconjunctivitis was caused by allergic inflammation. Mice with severe blepharoconjunctivitis showed thinning of the corneal epithelium, an irregular interface between the epithelium and stroma, subepithelial deposition of materials, and neovascularization of the stroma. Their corneas were cone shaped. Many transferase mediated-dUTP digoxigenin nick-end labeling-positive cells were recognized among superficial epithelial cells and keratocytes.

CONCLUSIONS

NC/Nga mice are a useful animal model of atopic blepharoconjunctivitis. Various corneal disorders in these mice may depend on their eye-scratching behavior.