Abstract
Purpose: :
To investigate corneal abnormalities in the NC/Nga mouse, which is an animal model of atopic dermatitis.
Methods: :
SPF NC/Nga mice were maintained in a bioclean room as SPF mice and kept in an uncontrolled conventional room as AD mice. To investigate histopathological changes of the eyelid, conjunctiva and cornea, the eyeballs together with upper and lower eyelids were extracted and fixed for examination by light and electron microscopy, or snap-frozen for immunohistochemistry. TUNEL staining was done to detect apoptotic cells. To estimate the number of eye scratching, video recordings were made. Mice with blepharoconjunctivitis were treated by palpebral application of tacroliums hydrate ointment once a day for a week, then assess the effect of tacroliums hydrate ointment by the eye scratching behavior.
Results: :
Mice kept in a conventional room (AD mice) suffered from various grades of blepharoconjunctivitis and scratched their eyes furiously. Tacroliums hydrate ointment reduced their eye scratching behavior. Histopathological investigation of the eyelid and conjunctiva revealed that this blepharoconjunctivitis was due to allergic inflammation. The normal architecture of the corneal epithelium was preserved in SPF mice, while 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. In AD mice, their corneas were cone-shaped, while the corneas of SPF mice had a normal shape. Numerous TUNEL-positive cells were recognized among superficial epithelial cells and keratocytes in AD mice, but undetectable in SPF mice.
Conclusions: :
NC/Nga mice are useful animal model of atopic blepharoconjunctivitis. Various corneal disorders in these mice may depend on their eye scratching behavior.
Keywords: cornea: stroma and keratocytes • keratoconus