Ophthalmic artery

Small hypophyseal and meningeal branches of the ICA are not visible in MR angiographies. The first originating vessel is the ophthalmic artery from the C3 segment. Distally the posterior communicating artery and subsequently the anterior choroidal artery arise from the ICA. A direct origin of the posterior cerebral artery from the ICA is referred to as embryonic type. 

The ophthalmic artery is the first major branch of the internal carotid artery and arises in the cavernous sinus. It passes through the optic foramen to supply the eye and other structures in the orbit. 

The meninges are supplied by branches of the external carotid artery, internal carotid artery and vertebral arteries. The most prominent branches from the external carotid artery are the middle meningeal artery and tributaries of the ascending pharyngeal and occipital arteries. Most of the branches from the internal carotid artery arise near the cavernous sinus and from the ophthalmic artery in the orbit. Branches from the vertebral artery arise at the foramen magnum. There are numerous meningeal anastomoses between these small arteries. 

The scalp is supplied by branches of the external carotid artery, particularly the superficial temporal, occipital and posterior auricular arteries. Above the orbit, there is a contribution from terminal branches of the ophthalmic artery. There is a rich anastomotic network between the various arteries of the scalp. 

Around the orbit. Branches of the external carotid artery can anastomose with branches of the ophthalmic artery if the internal carotid artery is severely stenosed or obstructed. Collateral flow from the external carotid artery into the orbit then passes retrogradely through the ophthalmic artery to fill the carotid siphon, middle cerebral artery and anterior cerebral artery. Sometimes flow may even reach the posterior cerebral artery and vertebrobasilar system. 

The presence of cranial neuropathy may result in a misdiagnosis of brainstem stroke. Cranial nerve palsies may result from local pressure from the false internal carotid artery lumen, thromboembolism or hemodynamic compromise to the blood supply of the nerve. Cranial nerve III receives its blood supply from the ophthalmic artery, branches of the internal carotid or the posterior cerebral artery and, consequently, may rarely become ischemic after carotid dissection. 

Giant cell arteritis is the most common vascuUtic cause of stroke and is associated particularly with posterior circulation ischemia (Nesher 2000 Ronthal et al. 2003 Eberhardt and Dhadly 2007). Medium and large arteries are affected, especially branches of the external carotid artery, the ophthalmic artery and the vertebral artery. The patients are elderly, with the diagnosis being rare under age 60 years. Malaise, polymyalgia and other systemic symptoms are frequently present. The erythrocyte sedimentation rate is usually raised, often to over 100 mm/h in the first hour. 

As previously mentioned, the retinotoxic effects of intracarotid BCNU can be largely minimized or avoided by using an infusion catheter that is advanced beyond the origin of the ophthalmic artery. If retinal complications develop, the risk-to-benefit ratio must be considered regarding the advisability of continued therapy. 

Retinal vascular changes and VL may be prevented by passing the internal carotid artery catheter beyond the ophthalmic artery before releasing the drug. 

Blood is supplied to the retina by the central retinal artery and choroidal blood vessels (Oyster, 1999). The central retinal artery arises from the ophthalmic artery, w hich in turn branches off the internal carotid artery. Upon entering the retina, the central retinal artery branches into deep capillary beds in the INL and superficial capillary beds in the GCL. Endothelial cells of retinal capillaries are joined by tight junctions, contributing to the blood/retinal barrier. There is litde or no autonomic regulation of the retinal circulation blood flow through these capillaries is instead primarily controlled by autoregulation (Wangsa-Wirawan and Linsenmeier, 2003). Retinal capillaries drain into the central retinal vein. 

Adverse ocular effects, such as ptosis, are on record (SEDA-15,118). Transient dizziness, diplopia, and partial blindness have been reported after the entry of lidocaine with adrenaline into the ophthalmic artery following mandibular block (97). A similar case after posterior alveolar block resulted in dizziness and diplopia for 3 hours when the patient stood up, possibly due to the entry of local anesthetic into the ophthalmic artery (SEDA-22,135). 

More selective application of thrombolysis has been attempted with injection of urokinase into the ophthalmic artery. Paques et al. (45) reported retrospectively on 26 eyes treated in this method, nine of which were combined central retinal artery occlusion (CRAO) and CRVO. The visual acuity improved significantly in only six... 

Paques M, Vallee JN, Herbreteau D, et al. Superselective ophthalmic artery fibrinolytic therapy for the treatment of central retinal vein occlusion. Br J Ophthalmol 2000 84 1387-1391. 

Fig.5.6e-I. Various locations of aneurysms (continued), e Small basilar trunk aneurysm and aneurysm at the PI segment, f Basilar tip aneurysm, g Acorn aneurysm, h ICA aneurysm at the origin of the Pcom artery, so-called Pcom aneurysm, i Aneurysm at the bifurcation of the pericallosal and callosomarginal artery, so-called pericallosal aneurysm, j MCA bifurcation aneurysm, k ICA aneurysm at the origin of the ophthalmic artery, so-called paraophthalmic aneurysm. I Distal carotid bifurcation aneurysm...

Fig. 5.31. a Paraophthalmic aneurysm. b On 3D rotational DSAthe ophthalmic artery is assumed to originate from the aneurysm, but after complete occlusion of the aneurysm this vessel remained patent (c)... 

Aneurysms related to the carotid artery in the region of the anterior clinoid process, the so-called para-clinoid aneurysms are often in association with the ophthalmic artery. They may originate in the cavernous sinus and extend into the subarachnoid space, carrying the risk of subarachnoid hemorrhage, even if the origin of the aneurysm is clearly extradural. Frequently presenting symptoms of aneurysms located within or around the cavernous sinus and the... 

The intraconal space is defined by the rectus muscles and their intercormecting septa. It contains the optic nerve, motor nerves, some blood vessels, and intraconal orbital fat tissue. Among the intraconal blood vessels, the ophthalmic artery, which branches off from the intracranial internal carotid artery, enters through the optic foramen. Near the orbital apex, the central retinal artery takes off from the ophthalmic artery and runs caudal to the optic nerve, whose dura mater it usually enters approximately 1 cm dorsal to the eyeball. 

Initially, at early embryonic stages, the ventral and dorsal aortas communicate by a certain number of arterial bridges, the aortic arches (1 to 4 in the craniocaudal direction). Other embryonic arteries are the primitive maxillary artery, dorsal ophthalmic artery, ventral ophthalmic artery, anterior cerebral artery and the longitudinal neural arteries (Fig. 18.1). 

During the subsequent stages, some of these arteries undergo modifications through regression in the regions of the ventral ophthalmic artery, dorsal aorta and the ventral portion of the first two aortic arches. 

The ophthalmic artery arises originally from the supraorbital branch of the stapedial artery which later becomes the middle meningeal artery. In addition, the orbital artery will also anastomose with the primitive (and later definitive) ophthalmic artery, from the supracavernous internal carotid artery. Because of the different variants in the involution of the proximal segment of the orbital or ophthalmic arteries, the supply to the orbit will finally arise exclusively from the ICA, the stapedial system (EGA) or both. 

Embryologically, the dorsal ophthalmic artery, the stapedial artery, the trigeminal artery and the primitive maxillary artery are involved in this anastomosis. 

Fig. 18.5a-c. Anatomical variation. Orbit supply entirely from the middle meningeal artery (arrow) a. On venous phase of left EGA angiography, choroidal blush is clearly shown (arrow) b. Internal carotid artery angiography demonstrates a large paraophthalmic aneurysm, but no ophthalmic artery is visualized from the ICA c... 

The sphenopalatine artery, the terminal branch of the internal maxillary artery enters the nasal cavity where it is divided into a septal, medial branch and a lateral branch that supplies the conchae. These two arteries have a distinctive appearance on the angiographic views. These branches usually anastomose with the anterior and posterior ethmoidal arteries, which arise from the ophthalmic artery system, at the anterior and posterior ethmoidal cells, and eventually connects the external and internal carotid... 

Kuru Y (1967) Meningeal branches of the ophthalmic artery. Acta Radiol 6 241-251... 

The initial study in idiopathic EPX should involve the internal carotid artery ipsilateral to the bleed, using both lateral and AP views in order to detect any lesion of the petrous or cavernous segment of this vessel. This also allows the evaluation of nasal fossa vascularity that originates from the ethmoidal arteries. Angiography of internal maxillary artery is then performed in lateral views to depict any culprit anastomoses with the internal carotid system, as the external carotid origin of the ophthalmic artery. These... 

Fig.20.4a,b. Patient with HHT disease suffering from recurrent EPX. Nasal fossa telangiectasias are vascularized by both septal and turbinate branches of the internal maxillary artery (lateral view a, small arrows) and by ethmoidal branches of the ophthalmic artery (lateral view b, small arrows)... 

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