Ischemic neuropathy of the optic nerve: anterior, posterior

At the heart of ischemic neuropathy of the optic nerve is acute violation of arterial blood circulation in the system of blood vessels that feed the optic nerve.

[1], [2], [3], [4], [5], [6]

Causes of the ischemic neuropathy of the optic nerve

In the development of this pathology, the following three factors play a major role: violation of general hemodynamics, local changes in the wall of blood vessels, coagulation and lipoprotein shifts in the blood.

Violations of general hemodynamics are most often caused by hypertension, hypotension, atherosclerosis, diabetes, the emergence of stressful situations and heavy bleeding, carotid artery atheromatism, occlusive diseases of brachiocephalic arteries, blood diseases, the development of giant cell arteritis.

Local factors. Currently, great importance is attached to local local factors that cause the formation of thrombi. Among them - a change in the endothelium of the vessel wall, the presence of atheromatous plaques and sites of stenosis with the formation of swirling blood flow. The presented factors determine the pathogenetically oriented therapy of this severe disease.

[7], [8], [9]

Symptoms of the ischemic neuropathy of the optic nerve

There are two forms of ischemic neuropathy - anterior and posterior. They can manifest as a partial (limited) or total (total) defeat.

[10], [11], [12]

Anterior ischemic neuropathy

Acute disturbance of blood circulation in the intrabulbar area of the optic nerve. Changes occurring in the head of the optic nerve are detected with ophthalmoscopy.

With total damage to the optic nerve, vision is reduced to hundredths and even to blindness, while partial - it remains high, but typical wedge-shaped scotomas are noted, and the vertex of the wedge always faces the fixation point of the eye. The wedge-shaped prolapse is explained by the sectoral nature of the optic nerve supply. Wedge-shaped defects, merging, cause a quadrant or a half-dip in the field of view. Defects of the field of vision are more often localized in its lower half. Vision is reduced within a few minutes or hours. Usually, patients accurately indicate the day and hour, when vision has sharply decreased. Sometimes there may be precursors in the form of headache or temporary blindness, but more often the disease develops without precursors. At an ophthalmoscopy the pale edematous disk of an optic nerve is visible. Vascular retinal vessels, primarily veins, change secondary. They are broad, dark, crimped. On the disk and in the parapapillary zone there may be hemorrhages.

The duration of the acute period of the disease is 4-5 weeks. Then the edema gradually decreases, the hemorrhages dissolve and the atrophy of the optic nerve of different degree of manifestation is manifested. Defects of the field of vision are preserved, although they can significantly decrease.

[13], [14], [15], [16]

Back ischemic neuropathy

Acute ischemic disorders develop along the optic nerve behind the eyeball - in the intraorbital department. These are the back manifestations of ischemic neuropathy. Pathogenesis and clinical course of the disease are identical to those of anterior ischemic neuropathy, but in the acute period there are no changes on the fundus. Disc of the optic nerve is of natural color with clear boundaries. Only after 4-5 weeks disc decolorization appears, partial or complete atrophy begins to develop. With total damage to the optic nerve, central vision can be reduced to hundredths or to blindness, as with anterior ischemic neuropathy, with partial visual acuity may be high, but in the field of vision, characteristic wedge-shaped prolapses are revealed, more often in the lower or lower-nasal regions. Diagnosis at an early stage is more difficult than with ischemia of the optic nerve head. Differential diagnosis is performed with retrobulbar neuritis, volume formations of the orbit and central nervous system.

In 1/3 of patients with ischemic neuropathy, the second eye is affected, on average after 1-3 years, but this interval can range from a few days to 10-15 years.

[17], [18], [19]

Treatment of the ischemic neuropathy of the optic nerve

Treatment of ischemic neuropathy should be complex, pathogenetically conditioned taking into account the general vascular pathology of the patient. First of all, the following is envisaged:

• antispasmodics (sermion, nicergoline, trental, xanthinol, nicotinic acid, etc.);
• thrombolytic agents - plasmin (fibrinolysin) and its activators (urokinase, gemase, kavikinase);
• anticoagulants;
• symptomatic means;
• vitamins of group B.

Carry out also magnetotherapy, electro- and laser stimulation of the optic nerve.

Patients who have undergone ischemic neuropathy of one eye should be under clinical supervision, they need to conduct appropriate preventive therapy.