Abstract
The region of the optic strut is sometimes traversed by some minor canals whose incidence and general characteristics have never been studied. As such canals could be the route for vessels that could interfere in the surgery of the orbital apex, we undertook a detailed anatomical study on a vast collection of dry skulls. The examination of 943 dry adult skulls and 360 foetal skulls was carried out to precise the anatomy of canals in the optic strut area, their development and relationships with the optic canal. A canal traversing the optic strut was present in 8.54 % of the orbits. Based on diameter, position within the optic strut, and thickness of the bony plate separating it from the optic canal or from the superior orbital fissure, the canals piercing the optic strut were classified into four types, which include the well-known duplication of the optic canal, different aspects of the metoptic canal and a type of canal that to our knowledge has never been reported. Warwick’s foramen was found in 0.74 % of orbits. The area of the optic strut is the frequent site of canals joining the orbit with the middle cranial fossa. Some of them can host the ophthalmic artery; others could be run by minor vessels which, however, could be the source of annoying bleedings in surgical procedures.
Similar content being viewed by others
References
Augier M (1931) Squelette céphalique. In: Nicolas A (ed) Poirier and Charpy traité d’anatomie humaine, vol 1. Masson et Cie, Paris
Berlis A, Putz R, Schumacher M (1992) Measurements and variations in the region of the optic canal. CT and anatomy. Radiologe 32:436–440
Bisaria KK, Kumar N, Jaiswal AK, Sharma PK, Mittal M, Bisaria SD (1996) An accessory foramen deep in the infraorbital fissure. J Anat 189:461–462
Bourjat P, Bittinghoffer B (1984) Radioanatomical variants of the optic canal. J Radiol 65:711–712
Burdan F, Umlawska W, Dworzanski W, Klepacz R, Szumilo J, Staroslawska E, Drop A (2011) Anatomical variances and dimensions of the superior orbital fissure and foramen ovale in adults. Folia Morphol 70:263–271
Calori L (1891) Su varie particolarità osteologiche della base del cranio umano. Mem R Acad Bologna (Serie V) 2:287–304
Choudry R, Choudry S, Anand C (1988) Duplication of optic canal in human skulls. J Anat 159:113–116
Diamond MK (1991) Homologies of the meningo-orbital arteries of humans: a reappraisal. J Anat 178:223–241
Govsa F, Kayalioglu G, Erturk M, Ozgur T (1999) The superior orbital fissure and its content. Surg Radiol Anat 21:181–185
Hauser G, De Stefano GF (1989) Epigenetic variants of the human skull. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart
Hayreh SS (1962) The ophthalmic artery: III. Branches. Br J Ophthalmol 46:212–247
Hayreh SS, Dass R (1962) The ophthalmic artery: I. Origin and intracranial and intracanalicular course. Br J Ophthalmol 46:65–98
Henle J (1871) Handbuch der Knochenlehre. Vieweg und sohn, Braunschweig
Housepian EM (1978) Microsurgical anatomy of the orbital apex and principle of transcranial orbital exploration. Clin Neurosurg 25:556–573
Jiménez-Castellanos J, Carmona A, Castellanos L, Catalina-Herrera CJ (1995) Microsurgical anatomy of the human ophthalmic artery: a mesoscopic study of its origin, course and collateral branches. Surg Radiol Anat 17:139–143
Jo-Osvatic A, Basic N, Basic JT, Nikolic V, Stimac D (1999) Topoanatomic relations of the ophthalmic artery viewed in four horizontal layers. Surg Radiol Anat 21:371–375
Keyes JEL (1935) Observation on four thousand optic foramina in human skulls of known origin. Arch Ophthalmol 13:538–568
Kier EL (1966) Embryology of the normal optic canal and its anomalies. An anatomic and roentgenographic study. Invest Radiol 1:346–362
Lang J (1977) Structure and postnatal organization of heretofore uninvestigated and infrequent ossifications of the sella turcica region. Acta Anat 99:121–139
Lasjaunias P, Brismar J, Moret J, Théron J (1978) Recurrent cavernous branches of the ophthalmic artery. Acta Radiol Diagn 19:553–560
Le Double AF (1903) Traité des Variations des os du crane de l’homme et de leur signification au point de vieu de l’anthropologie zoologique. Vigot Frères, Paris
Le Double AF (1906) Traité des Variations des os de la face de l’homme. Vigot Frères, Paris
Mağden AO, Kaynak S (1996) Bilateral duplication of the optic canals. Ann Anat 178:61–64
Patil GV, Kolagi S, Padmavathi G, Rairam GB (2011) The duplication of the optic canal in human skulls. J Clin Diagn Res 5:536–537
Perrini P, Cardia A, Fraser K, Lanzino G (2007) A microsurgical study of the anatomy and course of the ophthalmic artery and its possible dangerous anastomoses. J Neurosurg 106:142–150
Radoievitch S, Jovanovic S (1960) Les rapports du canal optique des enfants avec les sinus paranasaux postérieurs. Acta Anat 41:172–183
Reymond J, Kwiatkowski J, Wysocki J (2008) Clinical anatomy of the superior orbital fissure and the orbital apex. J Craniomaxillofac Surg 36:346–353
Sharma PK, Malhotra VK, Tewari SP (1988) Variations in shape of the superior orbital fissure. Anat Anz 165:55–56
Singh M (2005) Duplication of optic canal in adult Japanese human skulls. J Anat Soc India 54:1–9
Snijders RJM, Nicolaides KH (1994) Foetal biometry at 14–40 weeks gestation. Ultrasound Obstet Gynecol 4:34–48
Sömmering ST (1845) Trattato di osteologia e sindesmologia. Antonelli G, Venezia
Von Spee FG (1896) Kopf. von Bardeleben’s Handbuch der Anatomie des Menschen 1:93–280
Warwick R (1951) A juvenile skull exhibiting duplication of the optic canals and subdivision of the superior orbital fissure. J Anat 85:289–291
Willinsky R, Lasjaunias P, Berenstein A (1987) Intracavernous branches of the internal carotid artery. Comprehensive review of their variations. Surg Radiol Anat 9:201–215
Zoja G (1895) Sopra il foro ottico doppio. Boll Sci Pavia 7:65–69
Acknowledgments
I would like to thank Dr. M. Regoli for her invaluable assistance.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bertelli, E. Metoptic canal, duplication of the optic canal and Warwick’s foramen in human orbits. Anat Sci Int 89, 34–45 (2014). https://doi.org/10.1007/s12565-013-0197-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12565-013-0197-7