Quick Facts
The conjunctival glands are accessory lacrimal glands situated deep in the subconjunctival connective tissue, mainly in the upper fornix (Dorland, 2011).
Related parts of the anatomy
Structure and/or Key Feature(s)
The conjunctival glands (of Krause) are accessory lacrimal glands. They are located at the fornix of the conjunctiva, where approximately 40 glands are located in the superior fornix and a quarter as many in the inferior fornix. The accessory lacrimal glands are histologically similar to the main lacrimal gland; however, they lack parasympathetic innervation.
Anatomical Relations
The conjunctival glands are embedded within the frontal bone, deep to the frontal sinus. The glandular acini converge on a single duct that passes through the conjunctiva forming and anterior layer of the fornix to open onto the inside of the eyelid.
Function
The accessory lacrimal glands contribute to the production of the aqueous component of tears. This watery secretion maintains hydration of the epithelial surface of the eye, as well as containing several proteins, such as lysozymes and immunoglobulin A, which protect the surface of the eye from infection. The Glands of Krause produce only a small amount, about 10%, of total lacrimal secretions (Conrady, Joos and Patel, 2016). Based on the absence of parasympathetic innervation, it is thought that the accessory lacrimal glands provide basal levels of tear secretion, while the main gland is responsible for reflex tearing (by irritation of the conjunctiva or cornea) when required (Conrady, Joos and Patel, 2016).
References
Conrady, C. D., Joos, Z. P. and Patel, B. C. (2016) 'Review: The Lacrimal Gland and Its Role in Dry Eye', J Ophthalmol, 2016, 7542929.
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
