What Is Ischemic Optic Neuropathy?

Ischemic optic neuropathy is an acute failure of the arterial blood supply to the optic nerve that causes ischemia and hypoxia of the optic nerve, causing damage to the optic nerve. It is divided into anterior ischemic optic neuropathy and posterior ischemic disease, which occur in one or both eyes, and both eyes There may be intervals between onsets. At present, it is collectively referred to as anterior ischemic optic neuropathy. More common in older people, over 60 years old, women are more common than men.

Basic Information

nickname

Ischemic optic neuritis

English name

optic ischemic neuropathy

English alias

ischemicoptic neuropathy

Visiting department

Ophthalmology

Multiple groups

Elderly, over 60 years old, women are more common than men

Common locations

Monocular or binocular

Common causes

Have a systemic disease or eye disease that causes insufficient blood supply to the optic disc

Common symptoms

Visual field defects, nerve fiber layer bleeding, optic nerve atrophy, optic disc edema, visual field defects often have a short bundle of dark spots connected with physiological blind spots

Causes of ischemic optic neuropathy

Any systemic disease or eye disease that can cause insufficient blood supply to the optic disc can cause this disease. Such as hypertension, arteriosclerosis, temporal arteritis, carotid artery obstruction, diabetes, leukemia and erythrocytosis. Too low or too high intraocular pressure can cause imbalance between the perfusion pressure of the optic disc and the intraocular pressure. Due to changes in blood components and increased blood viscosity, the blood circulation is slowed, the amount of oxygen carried is reduced, and the optic disc is hypoxic.

Clinical manifestations of ischemic optic neuropathy

Generally, the vision loss is not serious, such as those caused by temporal arteritis, which is heavier, even without light perception. More sudden onset. The early swelling of the optic disc is light red, which is caused by the expansion of capillaries on the optic disc surface. It is more gray and white, and is mostly limited to a quadrant of the optic disc, which is consistent with visual field defects. Rarely bilateral. Located around the optic disc may be accompanied by a small amount of nerve fiber layer hemorrhage, which resolves by itself within 1 to 2 weeks. Optic nerve atrophy occurs after 1 to 2 months, and can be cup-shaped such as glaucoma optic nerve atrophy. Secondary to giant cell arteritis or arteriosclerosis, retinal blood vessels are generally normal. Those with hypertension or arteriosclerosis may show changes in retinal arteriosclerosis. If both eyes develop successively, that is, optic disc edema in one eye causes secondary optic nerve atrophy, and optic edema occurs in the other eye. Because the posterior ciliary artery branch supplies the optic disc in a partitioned manner, the visual field defect of this disease often has a short bundled dark spot connected to the physiological blind spot.

Ischemic optic neuropathy

Blood test

Erythrocyte sedimentation rate and routine blood tests exclude laboratory tests necessary for other systemic diseases.

2. Temporal Artery Biopsy

Temporal artery biopsy should be performed when necessary. Typical histological changes are granulomatous inflammation of the vascular wall. The arterial wall is involved in all three layers. The intima and middle layer of the blood vessel are more obvious. They are expressed as epithelioid macrophage lymphocytes and multinucleated giant cells. infiltration.

3. Visual field inspection

It is more common that the physiological blind spot is connected to the above-mentioned defect of the peripheral visual field through an arc-shaped defect area, which is very different from the damage of the visual path, indicating that the disease is the damage of the nerve fiber bundle starting from the optic disc.

4. Fundus fluorescein angiography

It has certain diagnostic value for ischemic optic neuropathy. One part of the optic disc is weakly fluorescent in the early stage and the other part of the optic disc is normal fluorescence. In the late stage of the angiography, there is obvious leakage of fluorescein and strong fluorescence in this weak fluorescent region. Corresponding to the part of the visual field defect, a small number of patients may show the existing local strong fluorescence even in the early stage of angiography, and the late fluorescence is more intense; however, regardless of the early manifestation of weak fluorescence or strong fluorescence, the obstructed and unobstructed areas of the optic disc There is still a significant asymmetry in the intensity of fluorescence. This asymmetry combined with the defect of the visual field still helps the diagnosis of this disease.

5. Blood tests in various laboratories.

Diagnosis of ischemic optic neuropathy

Those who are older than 40 years of age, have a sudden decrease in vision, and have a visual field defect that is associated with a physiological blind spot in the quadrant visual field defect, should consider the possibility of ischemic optic neuropathy. However, compressive optic neuropathy, demyelinating disease and hereditary diseases must be excluded.

1. Diagnosis of anterior ischemic optic neuropathy

Sudden decrease in vision, typical visual field defect; Headache, eye marks, especially caused by temporal arteritis; Optic disc is grayish white edema; Fundus fluorescein angiography shows that the optic disc has low fluorescence or slow or non-filling fluorescence; Raynaud Phenomenon; IOP recovery rate in the eye compression test was significantly reduced.

2. Diagnosis of posterior ischemic optic neuropathy

Sudden decrease in vision and visual field defect; No headache or eye pain; Fundus normal or slightly light on the nasal side of the optic disc with clear borders; Over 40 years old, often with hypertension, hypotension, arteriosclerosis or changes in blood composition ; Younger than 40 years old, mostly with Raynaud phenomenon or history of trauma or panic.

It is often difficult to diagnose the ischemic optic neuropathy in the later stages of clinical diagnosis, which is difficult to distinguish from optic papillitis. Some people think that abnormal blood flow diagrams or skull CT confirmed cerebral infarction areas can be used as a reference for diagnosis.

3. Imaging diagnosis

Fundus fluorescein angiography in the early stage showed no or weak fluorescence or delayed filling in the ischemic region of the optic disc, and the omentum circulation was normal. For example, some ischemic areas show strong fluorescence due to compensatory dilatation and leakage of superficial capillaries, and the asymmetry or unevenness of fluorescence in the ischemic and non-ischemic areas on the optic disc obstruction. After optic nerve atrophy, fluorescence angiography showed weak fluorescence or no fluorescence filling.

Treatment of ischemic optic neuropathy

First, the cause should be treated. Corticosteroid treatment can reduce edema caused by ischemia, improve blood flow disorders, and block vicious circulation. Oral acetazamides are used to reduce intraocular pressure and improve disc blood supply imbalance. At the same time, neurotrophic drugs such as vitamin B ₁ , B ₁₂ , ATP and coenzyme A can be given. Low-molecular dextran, compound salvia miltiorrhiza, Wei Nao Lu Tong, ligustrazine, etc. can be suitably used. Extracorporeal counterpulsation therapy can increase aortic diastolic blood pressure, thereby increasing blood flow in the common carotid artery.

Corticosteroids should be used with caution in patients with diabetes and hypertension, and systemic diseases such as hypertension, arteriosclerosis, and diabetes should be properly treated according to the etiology.

Prognosis of ischemic optic neuropathy

Ischemic optic neuropathy is usually in half a month to 2 months, and the optic disc edema can subside on its own, leaving a local or complete pale area. If treatment can be given in time, the visual function prognosis is better.