Occlusion of the central artery of the retina

The occlusion of the central artery of the retina is a rare and severe pathology of the Rétine related to a brutal interruption of the blood flow leading to irreversible cellular damage.

Physiopathology

The vascularization of the retina is ensured by a double arterial network :

the network choroïdien, major, which vascularized the photoreceivers (cones and Stick S), as well as the pigmentary epithelium. This vascular network is resulting from the posterior arteries ciliaires, they-even born from the ophthalmic artery.
the surface retinal network, which vascularized the nervous fibers, the ganglionic cells, and cells bipolar.

There exists in addition, at approximately 20% of the individuals, an additional artery: the cilio-retinal artery, which vascularized a more or less extended temporo-papillary area, and sometimes even the Mackled (in approximately a case on two). The occlusion of the central artery of the retina (by embolism or thrombosis) involves a brutal interruption of blood flow, therefore a retinal ischaemia which leads in less than 90 minutes to irreversible retinal lesions often leading to a fall of Vision deep and final: it is a infarction of the eye, and as in the heart, the retinal arterial network is final.

Diagnosis

At the time of a OACR, the patient complain about a fall of brutal vision, sometimes preceded by episodes of fugacious Amaurose. The eye is white and painless. With the examination, the measurement of the vision finds it ploughed up, often limited to a simple luminous perception. The reflex direct photomotor is abolished, the pupil is in Mydriase. The reflex consensual photomotor is preserved. With the Fund of eye, one observes retinal arteries initially hails. The embole is seldom visualized. After a few hours, the retina appears pale, œdématiée, with one mackled red cherry (by contrast).

Complementary examinations

The Angiographie with the Fluorescéine is not essential in urgency, and does not have to delay the treatment. It shows a very important delay of the diffusion of the dye in the retinal arterial network.

Evolution

The functional forecast of the OACR is very bad, and one observes only exceptionally a recovery of the vision. She testifies in very often to a subjacent cardiovascular pathology which explains arterial occlusion:

Pathology cardiac emboligene: auricular Fibrillation, calcified valvulopathy, Myxome of the auricle, etc
Athérosclérose: in particular the Athérome carotidien which, when the plates fissure, is ulcerated, or split up, is responsible for embolisms of Cholestérol or embolisms limestones.
Turbid of the coagulation
Vascularities: these systemic diseases, responsible for anomalies of the arterial walls, can give thromboses: Lupus, Disease of Takayashu, Syndrome of Churg and Strauss, Disease of Wegener, etc

One will have to thus carry out a complete assessment of the Risk factors cardiovascular, a cardiac assessment, a vascular assessment, and possibly a systemic assessment.

Treatment

The treatment of occlusions of the central artery of the retina remains very disappointing, in particular when he is not undertaken very precociously. One can all the same try to limit the aggravation of the disease by certain measurements:

Massage of the ocular spheres, while hoping to mobilize a embole,
Position of Trendelenbourg, in order to increase the retinal blood pressure,
Puncture of the room former to the needle, which can it also allow, by decreasing the intraocular pressure, to increase the blood pressure.

Other measurements are to be held on the young subjects, without physical tares, seen less than 6 hours after the appearance of the first signs: one will be able to try a Fibrinolyse in-situ after rise of a Cathéter in the ophthalmic artery, where one injects a drug able to destroy a blood clot.

Random links: