title: Morphological and morphometrical study of the nasal opening of nasolacrimal duct in man.
abstract: BACKGROUND
  Epiphora constitutes one of the major and very common problems in all age groups. Recent developments in ophthalmology such as balloon dilatation, stent implantation, laser therapy and endoscopy of the lacrimal drainage system raise the need for a detailed anatomical knowledge of this system. It is also important for formulation of principles and techniques in the management of acrimal problems. The aim of this study was to demonstrate variations in shape, size and location of the opening of the nasolacrimal duct and of the lacrimal fold.
  
  
  METHODS
  Twenty sagittal head sections were obtained, the nasal septum was removed and the lateral wall of the nasal cavity was exposed and examined. The opening of the nasolacrimal duct (NLD) was demonstrated and was subjected to anatomical observations for the shape, site, size, opening type and the presence of the lacrimal fold. The different measurements for the distances between the opening of NLD and anterior nasal spine, palate and inferior concha were made.
  
  
  RESULTS
  The examined specimens showed that the opening of the NLD was variable in shape taking the form of sulcus in 70% and fissure in 30% of specimens. The sulcus was either vertical or oblique while the fissure was either vertical, oblique or in the form of anteroposterior one. Regarding the location, the opening of the NLD was located at anterior one third below line of attachment of the inferiorconcha in nearly half of cases (45%). The lacrimal fold was present in most of examined specimens (70%) and absent in 30%. The fold take 5 different forms.
  
  
  CONCLUSIONS
  The knowledge of the morphology and morphometry of the lacrimal drainage system enables the ophthalmologist to plan intervention on the lacrimal drainage system precisely and avoid unnecessary manipulations and also minimizing the risk of injury during intra-nasal surgery.
authors.affiliation: Department of Anatomy and Embryology, Faculty of Medicine, Cairo University, Cario, Egypt. ehab.elshaarawy@yahoo.com.
authors.forename: E A A
authors.initials: EA
authors.lastname: Elshaarawy