Anatomy of the vertical lacrimal canaliculus and lacrimal punctum: a macroscopic study.

Purpose: To characterize the macroscopic anatomy of the vertical lacrimal canaliculus and the lacrimal punctum in relation to the tarsal plate.

Methods: Twenty-eight eyelids of 7 cadavers (mean age at death, 79.1 years; range, 65-93 years) were used for the investigation. The harvested eyelids were incised vertically around the central part of the upper and lower eyelids. The whole superior border of the upper tarsal plate and the whole inferior border of the lower tarsal plate were exposed by removing the soft tissues adjacent to them. We first examined whether these tarsal plates contained a lacrimal punctum. If the lacrimal punctum was found, we inserted a lacrimal probe to the punctum and measured the length covered by the tarsal plate using a millimeter ruler.

Results: All the tarsal plates contained the lacrimal punctum, and the mean length of the canaliculi covered by the tarsal plates was 2.82 mm (range, 2.3-3.0 mm) in the upper eyelid and 2.39 mm (range, 2.3-2.5 mm) in the lower eyelid.

Conclusions: Since the length of the vertical lacrimal canaliculus including the lacrimal punctum is generally 2 mm, they are considered as tarsal components in both the upper and lower eyelids.