Abstract
Purpose :
Inflammation and fibrosis in lacrimal-duct epithelium is known to be involved in the pathology of idiopathic nasolacrimal-duct obstruction, however, the definitive pathology has yet to be elucidated. Current literature suggests that a rabbit animal model could potentially be used for further characterization of the human nasolacrimal drainage system. In this study, we attempted to create a lacrimal-duct epithelial damage model and investigate the anatomical and functional change in rabbits.
Methods :
All animals in this study were treated in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. Under local anesthesia induced by an instillation of oxybuprocaine hydrochloride eye drops, 250μl of either benzalkonium chloride (BAC) (10%, 1%, or 0.1%) or phosphate buffered saline (PBS) was injected into the rabbit lacrimal duct once daily for 3 consecutive days (n=3 each). After sampling the lacrimal ducts, the degree of the tissue damage was examined by hematoxylin and eosin staining for histological examination and the barrier function was examined by Zonula occludens-1 (ZO-1), a tight junction protein, for immunofluorescence examinations.
Results :
In the histological examination, the disturbance of tissue construction such as shedding of epithelial cells or enucleated cells, as well as infiltration of neutrophils under the basement membrane, was observed in the BAC injection groups of 1% or more in comparison with the PBS injection group (control) and 0.1% of BAC injection group. Especially in the 10% BAC injection group, extremely tissue damage was observed and only basal cells were left. In the immunofluorescence examination, ZO-1 was expressed in the lacrimal-duct epithelial cells in the PBS and 0.1% BAC injection group, and disruption of ZO-1 was observed in the 1% and 10% BAC injection groups.
Conclusions :
We established an anatomical and functional lacrimal-duct epithelial cell damage model in rabbits with 1% or more BAC injection into the lacrimal duct. This model has the potential of being used to clarify the pathology and apply therapeutic treatment to nasolacrimal duct obstruction.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.