DEVELOPMENTAL ANATOMY OF NASOLACRIMAL DUCT

TLDR

The nasolacrimal duct’s development has been studied since 1950, with literature often cited and some original material, noting that the nasal connection may be incomplete at birth. The nasolacrimal duct originates from ectodermal thickening in the naso‑optic fissure that invaginates between the lateral nasal and maxillary processes, later canalizing to form a patent duct from the ocular to the nasal end.

Abstract

As A PART of the scientific exhibit of the American Academy of Ophthalmology and Otolaryngology, in 1950, I reviewed the developmental anatomy of the nasolacrimal duct. At that time, and since, I have been repeatedly asked for reprints of, or references to, the literature on this subject. Although much of the material used in the exhibit has been published in the anatomic, embryologic, and ophthalmologic literature, some of it is original, and the remainder bears repetition. The nasolacrimal passageway arises from a thickening of the ectoderm in the naso-optic fissure. The thickened ectoderm buries itself in the mesenchyme between the lateral nasal process and the maxillary process, detaches itself from the surface, and extends downward. Later, the epithelial cord canalizes and becomes patent at the ocular end and, finally, at its lower nasal end. The latter, the nasal connection, may often not be completed at birth. In the 7-mm., or