The prevalence of anatomical variations in the intraorbital part of the ophthalmic artery and its branches in cadavers

English: The human orbit contains various important structures that may show variations relating to their anatomy. This study focused on the intraorbital part of the ophthalmic artery in a South African cadaver sample in the Free State (UFS) and Western Cape provinces (UCT). Meyer pioneered the study of the ophthalmic artery as far back as 1887, with a main focus on its branches and their variations. Very limited investigation has been carried out in this field and available literature has little information on this. Currently no published data exists on the South African population with regard to intraorbital variations within the ophthalmic artery and its branches. Original research was conducted to address the problem of the lack of data. Dissections of the eyes were done to investigate and document the possible variations of the intraorbital part of the ophthalmic artery and its branches. The aim of the study was to determine the prevalence of anatomical variations in the intraorbital part of the ophthalmic artery and its branches in a cadaver sample. The results of the study will be of value to surgical interventionists treating patients with vascular diseases within the orbital region and also to the ophthalmology students studying the orbital vascular anatomy. A total number of 59 cadavers were utilised, and 118 eyes were dissected under the lighted magnifier and observed for variations. The sample consisted of 23 cadavers (46 eyes) from the Department of Basic Medical Sciences of the University of the Free State, and 36 cadavers (72 eyes) from the Department of Human Biology of the University of Cape Town. Sixteen types of variations were observed and documented. The ophthalmic artery crossed below the optic nerve in the left eye in 7.63% of cadavers at both institutions. No ophthalmic artery crossed below the optic nerve in the right eye in the UCT group, whereas 17.39% in the UFS group crossed below the optic nerve. Statistical analyses determined the frequencies of the variations. In certain individuals there were more than one type of variation which is in agreement with published literature. The majority of variations in branching patterns occurred bilaterally and in most cases, the variation in the left eye differed from the variation in the right eye. Males showed a higher frequency of variations. These findings may well contribute to clinical application in ophthalmology and radiology while it will also inform anatomy students studying the blood supply to the eye and surrounding structures.