Anatomic evaluation of the ophthalmic artery in optic canal decompression:a cadaver study of 20 optic canals

On the other hand, it is necessary to have a good knowledge of the anatomical structure of this region in the approach to OA Aneurysms.The variations on the arterial system of this region are more worthy of attention than the venous system (4,5,6,9,29).In neurosurgery, the recent advances in microsurgery techniques brought by technological developments have enabled an easier and more informed approach to surgery in this area.At the same time, the relationship between the anatomical structures of this area is just as important as before.It was with this aim that cadaver studies were used to investigate the relationship between the optic nerve and the █ INTRODUCTION Approaches and indications for surgery on the optic canal are limited.However, this area has always attracted attention because of its position in the cranium and its relation to surrounding anatomical structures.Surgery is performed on the posterior orbit, the optic canal (OC), and the superior orbital fissure for injuries to the optic nerve which may occur as a result of trauma, for pseudotumor cerebri, angioma in the posterior orbit, neurinoma, meningioma, malignant tumors, and sphenoid wing tumors, and for ophthalmic artery (OA) aneurysms which have an extension inside the canal (3,13,14,17,19,27).AIm: A relationship was shown in this study between the optic canal and the ophthalmic artery by cadaver study.It is intended that the anatomical and histological values which we obtained can be used as a guide in surgery mATERIAl and mEThODS: A surgical anatomical evaluation was made of twenty optic canals in ten cadavers fixed in 10% formaldehyde.These were evaluated together with measurements of the ophthalmic artery and histological sections of the surrounding structure. RESUlTS:The ophthalmic artery separated from the carotid at different positions.In our material, eight (40%) left the carotid from the upper internal part, six (30%) from the front internal part, four (20%) from the upper central part, and two (10%) emerged at the end of the cavernous segment of the middle of the carotid at a steep angle.In none of the material did the ophthalmic artery originate from any other vascular structure than the carotid.Whatever position the ophthalmic artery was in within the canal on entry, it followed the outer walls of the canal and left the canal in the lower external section of the optic nerve.In the literature, work on this area has been limited to examining the anatomical values and variations in the optic canal.The results in the present study have been obtained by combining the data with surgical anatomy.CONClUSION: This is a method of transcranial decompression of the optic canal which is safe for the vascular structures in and around the optic canal providing certain points are kept in mind.