THE OPHTHALMIC ARTERY: III. BRANCHES

Abstract

THE pioneer worker in the study of the ophthalmic artery, particularly its branches and their variations, was Meyer (1887), whose observations on twenty cases have been accepted more or less as classical for the last three- quarters of a century.No detailed investigation has since been carried out in this field and the descriptions of the branches of this artery which appear in the various text-books of anatomy and ophthalmology merely reflect his conclusions.Moreover, little information regarding the branches and their anomalies is available in the literature.It was therefore thought desirable to study this problem afresh in detail. MaterialThis study was carried out on 59 human orbits obtained from 36 cadavers from the dissection room.In 23 cadavers both orbits were examined, and only one side in the remaining thirteen.All the cadavers were those of persons past middle age, except three which were of children aged 4, 11, and 12 years. MethodNeoprene latex was injected in situ, either through the internal carotid artery or through the most proximal part of the ophthalmic artery, after opening the skull and removing the brain.The artery was first irrigated with water.After the injection, the part was covered with cotton wool soaked in 10 per cent.formalin for from 24 to 48 hours to coagulate the latex.The roof of the orbit was then opened and the ophthalmic artery and its branches were carefully studied with a low-power stereoscopic binocular dissection microscope.In the present paper the pattern of each of the various branches is described separately, depending on whether the ophthalmic artery crosses over or under the optic nerve in the second part of its course (Hayreh and Dass, 1962b); the two arrangements lead to obvious differences, each with its own characteristics. Observations and DiscussionThe branches of the ophthalmic artery may be classified conveniently in three ways (Whitnall, 1932):(A) According to the order of origin of the branches.