applied endoscopic anatomical evaluation of the lacrimal sac

introduction: dacryocystorhinostomy (dcr), a popular surgical procedure, has been performed using an endoscopic approach over recent years. excellent anatomical knowledge is required for this endoscopic surgical approach. this study was performed in order to better evaluate the anatomical features of the lacrimal apparatus from cadavers in the isfahan forensic center as a sample of the iranian population.   materials and methods: dcr was performed using a standard method on 26 cadaver eyes from the forensic center of isfahan. the lacrimal sac was exposed completely, then the anatomical features of the lacrimal sac and canaliculus were measured using a specified ruler.   results: a total of 26 male cadaveric eyes were used, of which four (16.7%) were probably non-caucasian. two (8%) of the eyes needed septoplasty, one (4%) needed uncinectomy, and none needed turbinoplasty. four (16%) lacrimal sacs were anterior to axilla, one (4%) was posterior and 20 (80%) were at the level of the axilla of the middle turbinate. the distance  from the nasal sill to the anterior edge of the lacrimal sac (from its mid-height) was 39.04 (±4.92) mm. the distance from the nasal sill to the posterior edge of the lacrimal sac (from its mid-height) was 45.50 (±4.47) mm. the width and length of the lacrimal sac was 7.54 (±1.44) mm and 13.16 (±5.37) mm, respectively. the distance from the anterior edge of the lacrimal sac to the posterior edge of the uncinate process was 14.06 (±3.00) mm, while the distance from the anterior nasal spine to the anterior edge of the lacrimal sac (from its mid-height) was 37.20 (±5.37) mm.the height of the fundus was 3.26 (±1.09) mm. the distance from the superior punctum to the fundus was 12.70 (±1.45) mm, and the distance from the inferior punctum to the fundus was 11.10 (±2.02) mm.   conclusion:  given the differences between the various studies conducted in order to evaluate the position of the lacrimal sac, studies such as this can help to better identify the position of lacrimal sac during surgery based on ethnic differences. in addition, these studies can help novice surgeons to better navigate in a surgical scenario.