Ocular surface inflammation impairs structure and function of meibomian gland

Abstract

Dysfunction of the meibomian glands alters secreted meibum quantitatively and qualitatively that can lead to damage to the ocular surface epithelium. In response to an unstable tear film cause by meibomian gland dysfunction, ocular surface epithelium is damaged and expresses inflammatory cytokines leading to secondary ocular inflammation. In turn, inflammatory disorders of the palpebral conjunctiva and lid margin may affect the structure and function of meibomian gland. The disorders include allergic conjunctivitis, long-term usage of contact lenses, dermatological diseases that affect conjunctival homeostasis, Stevens-Johnson's syndrome or chemical burning of the ocular surface and lid margin.

Keywords: Chemical burn; Conjunctivitis; Contact lens; Meibomian gland; Ocular surface inflammation; Rosacea.

Fig. 1

Morphologically abnormal configuration of meibomian glands in a 35-year-old male patient with chronic allergic conjunctivitis (case 1), a long-term (approximately 20 years) female user (39-year-old) of a soft contact lens (case2) and a 74-year-old male patient with a long-term application of antiglaucoma medications (details unknown) (case 3).

Fig. 2

Infra-red noninvasive meibography finding of a 59-year-old patient with systemic TS-1 anti-cancer treatment for gallbladder cancer. The meibo-score (Arita et al., 2008) are 3 in all of upper and lower eyelids of both eyes. A, B: right; C, D: left; A, C: upper eyelids; B, D: lower eyelids (reproduced from Mizoguchi et al., 2015).

Fig. 3

Multiple chalazion in a patient with acne rosacea. Chalazion are observed in upper and lower eyelids of both eyes of a 79-year-old woman suffering from acne rosacea (a). Black arrows indicate the chalazion. The patient was treated with ophthalmic ointment of erythromycin lactobionate, colistin sodium methanesulfonate and systemic administration of minocycline hydrochloride (b). A, C and E: right eye; B, D and F: left eye (reproduced from Shirai et al., 2015).

Fig. 4

Alkali burn with an exposure to slaked lime (Calcium hydroxide) of the eyelid of a 33-year-old man. Meibomian glands of which orifices locate to the burned area (red circles) gradually disappeared at day 10 and 40 (reproduced from Mizoguchi, 2015).

Fig. 5

Scanning electron microscopy shows the orifice of the meibomian gland in the mouse upper eyelid (a). Two days after the alkali burn in ocular surface the orifice is found to be plugged with debris-like material (b).

Fig. 6

A. Eyelids of a C57BL/6 mouse. Eyelids were excised and observed from the behind. Acini were observed (open arrows). B. Meibomian glands of a C57BL/6 mouse 20 day s after ocular surface alkali burn. Loss of the acini and dilated ducts were observed in the upper eyelid (white arrow). In the lower eyelid meibomian gland was not observed (black arrow). C. Histology of meibomian glands of a C57BL/6 mouse. D. Histopathology of meibomian glands in the upper eyelid of a C57BL/6 mouse 20 days after ocular surface alkali burn. Largely dilated duct (open arrow) of the meibomian glands is observed, acinar cells (black arrows) are also seen among hypercellular mesenchyme (reproduced from Mizoguchi, 2015).

Fig. 7

Three-dimensional reconstruction images of an uninjured meibomian gland (a) and the dilated duct of an eyelid specimen at 20 days after ocular surface alkali burn (b). Marked dilation with decreased number of acini are observed in a day 20 sample (a, reproduced from Parfitt et al., 2012).