Acute visual impairment

In the case of loss of vision in one eye (whether acute or gradually developing), the patient will first visit an ophthalmologist. In the case of sudden, abrupt loss of vision in both eyes, the underlying causes are mostly neurological in nature.

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

The main causes of acute visual impairment:

I. For both eyes:

1. Ischemic optic neuropathy.
2. Bilateral infarction in the vertebrobasilar system.
3. Toxic optic neuropathy.
4. Retrobulbar neuritis in multiple sclerosis.
5. Benign intracranial hypertension (Pseudotumor).
6. Artifactual (postangiographic).
7. Increased intracranial pressure.
8. Psychogenic.

II. For one eye:

1. Fracture of the base of the skull (anterior cranial fossa and orbit).
2. Arterio-sclerotic ischemic optic neuropathy.
3. Temporal arteritis.
4. Amaurosis fugax in stenosis of the internal carotid artery.
5. An attack of amblyopia with swelling of the optic nerve papilla due to increased intracranial pressure.
6. Retinal migraine (periodic vision loss)

I. Acute deterioration of vision in both eyes

Ischemic optic neuropathy. Retinal ischemia is observed simultaneously. Sometimes bilateral retinal ischemia occurs with aortic arch syndrome, with a rapid transition from a forward bend to a vertical position.

Vascular bilateral visual cortex lesion (bilateral infarction or TIA), features of basilar blood flow disturbance and sudden onset. Elderly individuals are at particular risk. Color vision impairment precedes symptoms; pupillary responses are normal; differentiation from visual agnosia is necessary.

Toxic optic neuropathy. Toxic lesions are typical, for example, for intoxication with methyl alcohol; tobacco and ethyl alcohol (tobacco-alcohol amblyopia progresses over several days or weeks), as well as methanol, disulfuram, cyanides, phenothiazines, isoniazid, antineoplastic drugs, trichloroethylene, etc.

Retrobulbar neuritis in multiple sclerosis as an initial symptom occurs in 16% of patients with multiple sclerosis and is manifested by acute, less often subacute, decrease in visual acuity. The most significant defect is noted in the central visual field. Retrobulbar neuritis is not always a manifestation of multiple sclerosis. Inflammatory or infectious processes that can affect the optic nerve can be different: tuberculosis, sarcoidosis, cryptococcosis, toxoplasmosis, syphilis (with subsequent development of optic nerve atrophy), Lyme disease, mycoplasma, brucellosis, etc. Viruses or viral encephalitis (measles, mumps, rubella, chickenpox, infectious mononucleosis, herpes zoster, hepatitis A, CMV, HTLV-1), sometimes accompanied by bilateral optic neuritis.

Benign intracranial hypertension is more often observed in girls and young obese women with menstrual irregularities (not a mandatory symptom). It develops gradually and is manifested mainly by headache, which is most often occipital, but can be generalized and asymmetric. The next most common symptom is visual impairment, which sometimes develops acutely. Less often, unilateral or bilateral damage to the abducens nerve is observed. There is edema of the optic nerve in the fundus. The cerebrospinal fluid pressure is increased to 250-450 mm H2O. Sometimes, CT or MRI can reveal a decrease in the size of the cerebral ventricles. Sometimes (with decreased visual acuity and no effect of conservative therapy), decompressive trepanation is indicated.

In most cases, idiopathic cases are observed; sometimes it develops against the background of endocrinopathy, with iron deficiency anemia, during pregnancy.

Artificial (postangiographic) cortical blindness (Anton's syndrome) in both eyes often develops due to toxic damage to the occipital lobes after angiography. Visual impairment usually disappears within 1-2 days.

Amblyopia attacks (attacks last seconds, in severe cases - several minutes) can be observed against the background of increased intracranial pressure. In the latter case, visual impairment is still more often bilateral. When examining the visual fields, an expansion of the blind spot and a narrowing of the visual fields along the periphery are revealed. In the fundus - gross congestion, sometimes hemorrhages in the area of the yellow spot. Subsequently, a more persistent decline in vision develops.

Psychogenic blindness develops acutely and more often in women prone to other psychogenic disorders (in the anamnesis or at the time of examination). Usually other functional-neurological stigmas are revealed ("lump in the throat", pseudoataxia, pseudoparesis, etc.). At the same time, pupillary reactions and the fundus remain normal; such patients do not behave like those who suddenly become blind (good tolerance to the symptom, "beautiful indifference"); examination does not reveal any reasons for blindness; optokinetic nystagmus is preserved, visual evoked potentials and EEG are unchanged.

II. Acute deterioration of vision in one eye (amblyopia and amaurosis)

Basal skull fracture in the optic canal region. This diagnosis is supported by history and signs of head trauma, anosmia or visible external lesions, pallor of the optic disc 3 weeks after injury, and appropriate radiographic findings.

Arteriosclerotic ischemic optic neuropathy. Characterized by sudden vision loss in one eye, not accompanied by pain in the eyeball. Sometimes there are precursors in the form of short-term episodes of visual impairment. Pseudoedema of the optic disc is detected, later pallor of the retina, pallor of the optic disc, never complete blindness. Cause: arteriosclerosis, often developing against the background of arterial hypertension and diabetes mellitus.

Temporal arteritis often leads to complete blindness, is observed in older people, more often in women. Almost all patients complain of headache, a tense painful temporal artery is palpated. There is usually an acceleration of ESR. Most often, the temporal artery is involved in the pathological process, but we are talking about a systemic disease.

Amaurosis fugax

In old age, with stenosis of the internal carotid artery (noise on the artery, contralateral hemisymptoms are noted), the most common cause of sudden and transient monocular vision loss is amavrosis fugax (from Latin - fleeting) - a transient retinal circulatory disorder. Blindness in one eye or some blurring of vision occurs in the patient suddenly or develops over several minutes or hours. At the same time, sensitivity disorders and transient weakness in the contralateral limbs are possible. The duration of the episode is from several minutes to several hours. A routine ophthalmological examination reveals a pronounced degree of development of atherosclerosis of the retinal vessels, which is common for people of this age.

In more than 90% of cases, amavrosis fugax is caused by an embolus in the retinal artery originating from the atherosclerotic wall of the ipsilateral internal carotid artery in the neck and carried by the bloodstream to the ophthalmic artery. Vision loss occurs as a result of retinal ischemia. Emboli are usually carried further by the bloodstream to the peripheral branches of the retinal artery; spontaneous thrombolysis is usually observed, and, as a result, rapid regression of symptoms.

In the acute stage, a collapsed state of the retinal artery is observed, or fluorescein angiography allows visualization of an embolus directed to the periphery of the retina. Rarely, however, this examination is available.

From the moment of the attack of amavrosis fugax, in 30% of cases during the following year, cerebrovascular accident develops. Doppler ultrasonography is the diagnostic method of choice in these cases and should be performed immediately if carotid artery stenosis is suspected.

Retrobulbar neuritis develops acutely, but is most severe in the first 4 days, then improves over several days or weeks. It is sometimes accompanied by eye pain and "flickering" when moving the eyes. It is observed mainly in young people; it never leads to complete blindness. Loss of vision is usually unilateral, but bilateral retrobulbar neuritis also occurs. At first, the fundus is normal. The most significant defect is noted in the central visual field (central scotoma). In many cases (from 17 to 85%), these patients subsequently develop multiple sclerosis.

The cause may also be other (in addition to multiple sclerosis) demyelinating diseases (acute disseminated encephalomyelitis), syphilis (acute optic neuritis; but it can also be bilateral).

Eye disease. Intraocular inflammatory processes; retinal detachment; Eales syndrome - hemorrhages into the vitreous body and retina of various etiologies (tuberculosis, syphilis, other infections, blood diseases) with a picture of retinal perivasculitis.

Retinal migraine (retinal migraine) is characterized by attacks of blindness in one eye or monocular scotoma due to circulatory problems in the central retinal artery system. This form of migraine may alternate or be combined with attacks of migraine without aura or with ophthalmic migraine.

Ophthalmic migraine is characterized by migraine attacks with homonymous visual disturbances (zigzags, sparks, flashes, etc., as well as absolute or relative scotomas). There is no true loss of vision.