The Feasibility of Short-term Dry Eye Animal Model Using Concanavalin A

ABSTRACT

PURPOSE: To evaluate the possibility of short-term dry eye model in rabbits by injection of concanavalin A (conA) to the lacrimal and haderian gland of rabbits. METHODS: We injected conA (10 mg/ml, 0.05 ml) to the lacrimal and haderian gland of rabbits twice to induce inflammation of lacrimal gland and compared with saline-injected control by lacrimal gland biopsy with H&E staining for identification of inflammation. The ratio of lacrimal secretion was evaluated by Schirmer test (preinjection vs. postinjection of conA) for 10 days and the number of goblet cells was counted in 10 consecutive high power field using impression cytology with PAS staining. The corneal & conjunctival apoptotic cell deaths were investigated with TUNEL staining 10 days after injection. RESULTS: Infiltration of inflammatory cells and destructed normal architecture of lacrimal gland was found only in conA injected group till 10 days. The Schirmer test showed marked reduction (0.56+/-0.26) by 5days after injection compared with control group (1.07+/-0.35) (p=0.02) and its significant difference was maintained till 10days. The number of goblet cell was 9.70+/-5.03/x200HPF, which was statistically significant decreased compared to control (47.50+/-17.13/x200HPF) at 10 days (p=0.00). Apoptotic cells were increased in injected eye (26.20+/-4.27) compared with those in control (16.60+/-2.70). CONCLUSIONS: Injection of conA to lacrimal glands in rabbit shows decrease of lacrimal secretion and similar cytological changes of the cornea and conjunctiva in human dry eye patients. It suggests its possible feasibility of short-term dry eye animal model for the 10 days.