Abstract
Purpose:
As a convenient dry-eye mouse model, we previously reported an exorbital lacrimal gland (ELG) excision model (Shinomiya et al. ARVO 2012) and researched whether or not that model could be improved. The purpose of this present study was to report the usefulness of a new dry-eye mouse model produced by ELG and intraorbital lacrimal gland (ILG) excision.
Methods:
Unilateral ELG and ILG excision was performed on 10-week-old male LysM-eGFP(+/-) mice. To evaluate dry-eye symptoms, we performed fluorescein staining and measured tear production pre and post surgery. Four weeks post surgery, the eyeball and eyelid including bulbar and palpebral conjunctiva were enucleated, fixed with 10% formalin, embedded in compound, and frozen. Serial sections were cut, stained with hematoxylin-eosin (HE), and observed by light microscopy to assess the histological change of the cornea and conjunctiva. The sections were also observed under a fluorescence microscope without staining to determine neutrophil infiltration.
Results:
Tear production in the ELG and ILG excised mice was significantly decreased compared with untreated controls, and severe inflammatory changes were observed in the corneal surface at 2 weeks post surgery. Examination of the HE stained sections revealed significant severe inflammatory changes such as ulceration, cell infiltration, and neovascularization in the corneas of the ELG and ILG excised mice. Moreover, significant inflammatory cell infiltration into the mucosal and submucosal layer, as well as conjunctival epithelial hyperplasia, was observed in the conjunctiva of those mice. The main infiltrating cells in the cornea and the conjunctiva were mostly neutrophils which showed a unique green fluorescence.
Conclusions:
Severe tear volume reduction and corneal and conjunctival inflammatory change was induced, thus indicating that the ELG and ILG excised mouse is suitable for a severe dry-eye mouse model and useful for the investigation of pathogenesis of tear-volume reduction type dry-eye. It is thought that inflammatory changes on the ocular surface of this model were induced secondarily by persistent severe tear decrease.
Keywords: 480 cornea: basic science •
637 pathology: experimental