The lacrimal gland is roughly almond-sized and located anteriorly in the superolateral aspect of the extraconal space of the orbit. It has two lobes, a larger orbital lobe that extends deep into the orbital septum and a smaller palpebral lobe. Its orbital lobe sits in the lacrimal fossa of the orbit on the lateral margin of the levator palpebrae superioris muscle.
The lacrimal gland measures ~14.5 mm in axial length, 18 mm in coronal length and ~4.5 mm sagittal length (thickness). The size of the lacrimal gland decreases with age . Its cellular structure is similar to the salivary glands but it is unique in that it is composed of both epithelial and lymphoid tissue .
It drains via many small ducts into the lateral aspect of the superior conjunctival fornix.
- lacrimal tributaries draining to the superior ophthalmic vein
Secretomotor parasympathetic fibers via the greater petrosal nerve synapse in the pterygopalatine ganglion. Postganglionic fibers continue into the orbit via the zygomatic nerve which anastomoses with the lacrimal nerve.
Lymphatics of all the orbital structures drain to the preauricular and parotid lymph nodes through the eyelids and cheeks.
- bilateral enlargement
- unilateral enlargement
History and etymology
"Lacrima" is the Latin word for "a tear". Some speculate that the Latin word may have derived from a copyist's error writing λακρύ instead of δάκρυ ("dacro"), the Greek word for "a tear".
The gland was originally noted by Galen but was more thoroughly described in 1574 by Caracanus of Milan, a student of Fallopius. In 1662, N Stensen demonstrated that tears were formed by the gland and did not originate in the brain, as previously thought.