The Ophthalmic Arterial Complex in Angiographic Diagnosis

Abstract

The clinical course of all intraorbital space-occupying lesions is essentially the same, regardless of their nature. Characteristically, progressive unilateral proptosis, disturbance of ocular motility, and perhaps decreased vision and mild pain are noted. Any one or all of these signs may also occur with certain intracranial and periorbital processes secondarily affecting the orbit. If physical examination and plain skull or orbital roentgenograms fail to establish the nature or even the presence of a lesion with fair certainty, the clinician may elect to observe the patient rather than to risk orbital exploration, a course which can be hazardous. If the diagnosis remains in doubt, special roentgen procedures such as carotid angiography may be advantageous in visualizing the ophthalmic arterial complex. This technic has been described by a number of authors (1, 3–7, 10–12, 14), its practical importance being first recognized by Grino and Billet (7), and emphasized more recently by Krayenbühl (10, 11) and Di Chiro (5). In the past year we have encountered several such cases in which angiography has been of value. This stimulated us to review all similar cases to estimate the merits of the procedure. Anatomy Initially, we found a review of the anatomy of the ophthalmic artery of benefit (15). The main trunk arises as a vertical branch from the medial aspect of the carotid siphon as it exits from the cavernous sinus. The artery then courses forward and somewhat upward, accompanying the optic nerve into the optic canal where both are anchored in the dural sheath of the nerve. The two separate as they leave the canal, and the artery passes along the medial wall of the orbit and sends off branches to the globe and other orbital structures. It gradually narrows and ends by dividing into the nasal and supratrochlear (frontal) arteries. The significant branches of the ophthalmic artery include the ocular (the central retinal and the long and short posterior ciliary arteries supplying the globe) and the orbital (the supraorbital, muscular, posterior ethmoidal, nasal, and supratrochlear (frontal) arteries), as well as the lacrimal and anterior ethmoidal arteries. These last two communicate in turn with the recurrent and anterior meningeal arteries (Fig. 1). Angiographic Anatomy In 300 normal carotid angiographic examinations, opacification of the proximal main branch of the ophthalmic artery occurred almost simultaneously with filling of the upper loop of the carotid siphon. The more distal branches were seen for two or three seconds afterward. Between two and five seconds, the choroid plexus of the eye, supplied mainly by the short posterior ciliary arteries, was observed as a thin crescent near the anterior third of the orbit. The veins of the orbit were seen poorly, if at all. In 200 of these cases, the contrast medium was 50 per cent diatrizoate (Hypaque), and in all the proximal 2 to 3 cm. of the main trunk was recognizable.