Lacrimal System Essay

Anatomy of the Lacrimal System

Study of the lacrimal system is a synthesis of two disciplines, ophthalmology and otorhinolaryngology, which work closely together in the treatment of nasolacrimal disorders. A thorough understanding of the anatomy of the lacrimal system will help the surgeon to reach correct diagnosis, facilitate the chance of a successful surgical outcome and makes the surgeon confident of his skills. The lacrimal drainage system anatomy can be discussed under following components:
1. Embryology
2. Osteology
3. Nasal and paranasal sinuses
4. Secretory system
5. Excretory system
Embryology
Familiarity with lacrimal system embryology is necessary to understand congenital abnormalities of the nasolacrimal drainage system.
Secrtory

The nasal septum bisects the nasal cavity and comprises three portions: the bony perpendicular plate of the ethmoid (superoanterior) and the vomer (posterior and anteroinferior), a cartilaginous anterior triangle, and an inferior membranous columella that divides the nares anteriorly. Laterally, the nasal wall has three or more horizontal ridges termed turbinates, with a corresponding meatus below each (Figure
1.4). During the sixth week of embryologic development, before cartilage forms in the walls of the primitive nasal cavities, linear outgrowths of the lining epithelium occur on the sides and roof of each nasal side.
Each outgrowing gutter becomes a meatus, whereas the ridges left behind form the turbinates.8,16
The inferior turbinate is the largest, arising from the medial wall of the maxillary sinus. The smaller and more posterior middle, superior, and supreme (if present) turbinates are outcroppings of the ethmoid bone. The supreme turbinate may be found in up to 65% of patients.
The inferior turbinate is visualized by directing a nasal speculum parallel to the fl oor of the nasal cavity. The