title: Surgical anatomy of the ophthalmic artery: its origin and proximal course.
abstract: OBJECTIVE
  We examined the surgical anatomy of the ophthalmic artery (OA) by dissection of cadaver heads, evaluating the anatomic relationships between the origin of the OA and both its proximal course and surrounding structures. In addition, we demonstrated the surgical application of these anatomic features for safe surgical exploration of this region.
  
  
  METHODS
  Through anatomic dissection, the origin of the OA was examined in both sides of 25 formalin-fixed and 10 fresh cadaver specimens. The following parameters were evaluated: the location of the origin of the OA in relation to the dural rings, the topographic relationship of the paraclinoid region, and the location of the dural penetrating point of the OA in the optic canal.
  
  
  RESULTS
  The OA originated from the internal carotid artery within the intradural space in 49% of cases, just above the upper dural ring in 37%, at the clinoid segment in 7%, and within the cavernous sinus in 6%. The dural penetrating point of the OA was anterior to the falciform ligament, and thereby in the optic canal, in 74% of cases, ventral to the falciform ligament in 19%, and posterior to the falciform ligament in 7%. The anterior circumference point of the upper dural ring, the point at which the upper dural ring intersects the anterior edge of the internal carotid artery, was more anterior to the falciform ligament in 40% of cases and ventral and posterior to the falciform ligament in 16.4% and 43.6%, respectively.
  
  
  CONCLUSIONS
  Our anatomic findings demonstrate anatomic variation of the OA in terms of its region of origin. Several anatomic points that were noteworthy during surgical exploration of this region are discussed.
authors.affiliation: Department of Neurosurgery, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Phuong
authors.initials: P
authors.lastname: Huynh-Le
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Natori
authors.forename: Tomio
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D002102:Cadaver; D002343:Carotid Artery, Internal / Q000033:anatomy & histology* / Q000601:surgery; D002426:Cavernous Sinus / Q000033:anatomy & histology / Q000601:surgery; D004210:Dissection / Q000379:methods*; D006801:Humans; D008866:Microsurgery / Q000379:methods*; D009880:Ophthalmic Artery / Q000033:anatomy & histology* / Q000601:surgery