Meibomian gland dysfunction model induced with complete Freund's adjuvant in C57BL/6 mice

To establish a new inflammatory animal model of meibomian gland dysfunction (MGD) in C57BL/6 mice.

C57BL/6 mice were randomly divided into complete Freund's adjuvant (CFA) group (14 animals, 14 eyes), naphthazolin hydrochloride (NH) group (14 animals, 14 eyes) and control group (14 animals, 14 eyes). In CFA group, CFA was used in eyelid conjunctiva injection; in NH group, NH eye drops were used twice a day; control group was injected with equal dose of saline at the same time point and same site with animals in CFA group. The meibomian gland orifices score (MGOS) was evaluated on a scale of 0 to 3 in the middle five meibomian gland orifices of the upper and lower eyelid using slit lamp. After the successful induction of each animal model, intense pulsed light (IPL) was introduced on each mouse in CFA and NH group. Oil red O (ORO), hematoxylin and eosin (H&E) staining were performed before and after successful induction of CFA, NH and control group.

At 12wk after CFA injection, inflammatory cell infiltration and fiber necrosis was observed, with acinar density and duct dilatation significantly lower compared with control group. In NH group, the meibomian gland acini were relatively smaller and deformed compared with control group, the number of meibomian gland acini was also slightly lower. No inflammatory cell or fiber necrosis was observed in NH group. After three times of IPL treatment (5/10 mice in each group, and the other 5 mice served as non-IPL control), MGOS was significantly lower in IPL-treated mice in NH group (P<0.01). After three times of IPL treatment, the MGOS of NH group was significantly lower than that in the CFA group (P<0.01).

We develop a novel animal model that studies the role of inflammation in the development of MGD and IPL treatment. This model indicates that persistent inflammatory state may be the cause of MGD and weaken the therapeutic effect of IPL.