The nasolacrimal apparatus is intimately associated with the lateral nasal wall and may be approached using an endoscopic technique. This study was undertaken to describe in detail the gross anatomy of the nasolacrimal duct orifice in relation to various landmarks of the lateral nasal wall to improve the safety and efficiency of endoscopic surgical procedures. The study was conducted on 25 sagittal sections of adult cadavers in the Department of Anatomy, Kasturba Medical College, Manipal. The parameters measured were the distance from nasolacrimal duct orifice (NO) to the anterior end of middle concha (MC), distance from NO to the anterior nasal spine (ANS), distance from NO to the nasal floor (NF), distance from NO to anterior end of the inferior concha (AIC), and distance from NO to posterior end of the inferior concha (PIC). The shape of the NO was also observed and classified as oval, round and slit. The distance from NO to ANS was 2.73± 0.26 cm, the distance from NO to NF was 1.19± 0.34 cm, the distance between NO to MC, NO to AIC and PIC were 2.55 ±0.28 cm, 1.85±0.3 cm and 3.4±0.36 cm respectively. We also observed 3 types of shapes of NO, majority were slit like followed by oval and round. Knowledge of the anatomy of the nasolacrimal apparatus is essential for the surgeon during the performance of endonasal cystorhinostomies and maxillary osteotomies.
Key words: Nasolacrimal duct orifice, anterior nasal spine, middle concha, inferior concha