accessory lacrimal gland

The accessory lacrimal glands (glandulae lacrimales accessoriae) are serous glands of the eyelid and conjunctiva that supplement the main lacrimal gland in producing the aqueous component of tears. Key examples include the glands of Krause (in the lacrimal sac region) and the glands of Wolfring (on the inner surface of the upper eyelid).

The glands of Wolfring are located in the subconjunctival tissue near the tarsal fold on the inner surface of the upper eyelid, while the glands of Krause are found in the conjunctival fornix. Together they are distributed throughout the upper and lower eyelid conjunctiva.

Accessory lacrimal glands continuously produce the aqueous (watery) component of the tear film, contributing to the baseline (basal) tear production that maintains corneal moisture between blinks. The main lacrimal gland produces reflex tears (such as those triggered by irritation or emotion), while the accessory glands maintain baseline lubrication.

Dry eye disease (keratoconjunctivitis sicca) involves reduced tear production from both the main and accessory lacrimal glands. Sjögren's syndrome — an autoimmune condition — attacks lacrimal gland tissue including accessory glands, causing severe dry eye. Cicatrizing conjunctivitis can damage the accessory glands in the eyelid.

The main lacrimal gland is a large, well-defined gland in the superolateral orbit responsible for reflex tear production, while the accessory lacrimal glands are small, numerous glands within the eyelid conjunctiva responsible for continuous basal tear secretion. Together they ensure adequate corneal lubrication under all conditions.