Optic neuritis

Inflammatory process in the optic nerve - neuritis - can develop both in its fibers and in the membranes. On the clinical course, two forms of optic neuritis are distinguished: intrabulbar and retrobulbar.

Optic neuritis is an inflammatory, infectious or demyelinating process that affects the optic nerve. Can be classified by ophthalmoscopy and etiologically.

Ophthalmoscopic classification

1. Retrobulbaric neuritis, in which the optic disc has a normal appearance, at least at the onset of the disease. Most often, retrobulbar neuritis in adults is associated with multiple sclerosis.
2. Papillitis is a pathological process in which the optic nerve disk is affected primarily or secondary to changes in the retina. It is characterized by hyperemia and edema of the disc of various degrees, which can be accompanied by parapapillary hemorrhages in the form of "flame tongues". Cages in the posterior part of the vitreous can be seen. Papillitis is the most frequent type of neuritis in children, but it can also occur in adults.
3. Neuroretinitis - a papillitis in a combination to an inflammation of a layer of nervous fibers of a retina. The "star shape" in the macular area, representing a solid exudate, may initially be absent, then appears within a few days or weeks and becomes more noticeable after resolution of the edema of the disc. In some cases, there is parapapillary retinal edema and macular edema. Neuroretinitis is a rarer type of optic neuritis and is most often associated with viral infections and cat scratch disease. Among other reasons - syphilis and Lyme disease. In most cases this is a self-limiting disease that ends in 6-12 months.

Neuroretinitis is not a manifestation of demyelination.

Etiological classification

1. Demyelinating, the most common etiology.
2. Parainfectious, may be the result of a viral infection or vaccination.
3. Infectious, can be rhinogenic or associated with the disease of "cat scratch", syphilis, Lyme disease, cryptococcal meningitis in AIDS and herpes zoster,
4. Autoimmune, associated with systemic autoimmune diseases.

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

Intrabulbar neuritis of the optic nerve

Intrabulbar neuritis (papillitis) - inflammation of the intraocular part of the optic nerve, from the level of the retina to the trellis plate of the sclera. This department is also called the optic nerve head. With ophthalmoscopy, this part of the optic nerve is available for examination, and the doctor in detail can follow the entire course of the inflammatory process.

Causes of intrabulbar neuritis. The causes of the disease are manifold. Inflammatory agents can be:

• staphylo- and streptococci,
• causative agents of specific infections - gonorrhea, syphilis, diphtheria, brucellosis, toxoplasmosis, malaria, smallpox, typhus, etc.,
• viruses of influenza, parainfluenza, herpes zoster, etc.

The inflammatory process in the optic nerve is always secondary, i.e., is a complication of the common infection or focal inflammation of an organ, therefore, when a neuritis of the optic nerve arises, the therapist's consultation is always necessary. The development of the disease can lead to:

• inflammatory conditions of the eye (keratitis, iridocyclitis, choroiditis, uveopapillitis - inflammation of the vascular tract and the optic nerve head);
• diseases of the orbit (phlegmon, periostitis) and her trauma;
• inflammatory processes in the paranasal sinuses (sinusitis, frontal sinusitis, etc.);
• tonsillitis and pharyngolaringitis;
• caries;
• inflammatory diseases of the brain and its membranes (encephalitis, meningitis, arachnoiditis);
• common acute and chronic infections.

Of the latter, the cause of the development of optic neuritis is most often acute respiratory viral infection (ARVI), influenza and parainfluenza. The anamnesis of such patients is very typical: 5-6 days after acute respiratory viral infection or influenza accompanied by fever, cough, runny nose, malaise, there is a "spot" or "fog" before the eye and vision decreases sharply, ie, symptomatic of neuritis of the visual nerve.

Symptoms of intrabulbar neuritis. The onset of the disease is acute. Infection penetrates through the perivascular spaces and the vitreous. There are total and partial damage to the optic nerve. With total damage, vision is reduced to hundredths, and even blindness may occur, partial vision may be high, up to 1.0, but central and paracentral scotomes are marked in the field of vision with a rounded, oval and arco-like shape. The new adaptation and color perception are thereby reduced. The parameters of the critical frequency of confluence of flickering and lability of the optic nerve are low. The functions of the eye are determined by the degree of involvement of the papillomacicular bundle in the inflammatory process.

Ophthalmoscopic picture: all pathological changes are concentrated in the area of the optic disc. The disk is hyperemic, the color can merge with the background of the retina, the tissue is edematous, the edema is exudative. The boundaries of the disk are grayed out, but there is no big promising, as with stagnant disks, is not observed. The exudate can fill the vascular funnel of the disc and implant the posterior layers of the vitreous. The eye bottom in these cases is not clearly visible. On the disk or near it, banded and dashed hemorrhages are noted. Arteries and veins are moderately expanded.

On fluorescent angiography, hyperfluorescence is noted: with total lesion of the entire disk, with partial - corresponding zones.

The duration of the acute period is 3-5 weeks. Then the swelling gradually decreases, the boundaries of the disc become clear, the hemorrhages dissolve. The process can end with complete recovery and restoration of visual functions, even if initially they were very low. In severe neuritis, depending on the type of infection and the severity of its course, the death of nerve fibers, their fragmentary decay and replacement with glial tissue, ie, the process results in the atrophy of the optic nerve. The degree of severity of atrophy varies - from insignificant to complete, which determines the functions of the eye. Thus, the outcome of neuritis is the range from complete recovery to absolute blindness. At an atrophy of an optic nerve on an eyeground the monotonously pale disk with precise borders and narrow thread-like vessels is visible.

Retrobulbar neuritis of the optic nerve

Retrobulbar neuritis is an inflammation of the optic nerve in the area from the eyeball to the chiasma.

The causes of the development of retrobulbar neuritis are the same as those of the intrabulbar, to which a descending infection joins with diseases of the brain and its membranes. In recent years, one of the most common causes of this form of neuritis of the optic nerve have become demyelinating diseases of the nervous system and multiple sclerosis. Although the latter does not belong to the true inflammatory processes, in the whole world ophthalmological literature, lesions of the visual organ in this disease are described in the section devoted to retrobulbar neuritis, since the clinical manifestations of optic nerve lesions in multiple sclerosis are characteristic of retrobulbar neuritis.

Symptoms of retrobulbar neuritis. There are three forms of retrobulbar neuritis - peripheral, axial and transversal.

In the peripheral form, the inflammatory process begins with the optic nerve shells and spreads through the septa to its tissue. The inflammatory process has an interstitial character and is accompanied by an accumulation of exudative effusion in the subdural and subarachnoid space of the optic nerve. The main complaints of patients with peripheral neuritis - pain in the area of the orbit, intensifying with movements of the eyeball (shell pain). Central vision is not disturbed, but the uneven concentric narrowing of the peripheral boundaries by 20-40 ° is detected in the field of vision. Functional tests can be within normal limits.

With the axial form (observed most often), the inflammatory process develops predominantly in the axial bundle, accompanied by a sharp decrease in central vision and the appearance of central cattle in the field of vision. Functional tests are significantly reduced.

The transversal form is the most severe: the inflammatory process captures the entire tissue of the optic nerve. Vision is reduced to hundredths and even to blindness. Inflammation can begin on the periphery or in the axial bundle, and then on the septum spreads to the rest of the tissue, causing an appropriate picture of inflammation of the optic nerve. Functional tests are extremely low.

With all forms of retrobulbar neuritis in the acute period of the disease, there are no changes on the fundus, only after 3-4 weeks decoloration of the temporal half or the entire disk appears - a descending partial or total atrophy of the optic nerve. The outcome of retrobulbar neuritis, as well as intrabulbar, varies from full recovery to absolute blindness of the affected eye.

Treatment of optic neuritis

The main direction of therapy for neuritis (intra- and retrobulbar) should be etiopathogenetic depending on the cause of the disease, but in practice it is not always possible to establish it. First of all, appoint:

• antibiotics of the penicillin series and a wide spectrum of action, it is undesirable to use streptomycin and other antibiotics of this group;
• sulfanilamide preparations;
• antihistamines;
• local hormonal (para- and retrobulbar) therapy, in severe cases - general;
• complex antiviral therapy for the viral etiology of the disease: antiviral drugs (acyclovir, ganciclovir, etc.) and inducers of interferonogenesis (poludan, pyrogenal, amixin); the use of corticosteroids is a contentious issue;
• symptomatic therapy: detoxifying agents (glucose, haemodez, rheopolyglucin); drugs that improve oxidation-reduction and metabolic processes; vitamins C and B groups.

In the late stages of the onset of symptoms of optic nerve atrophy, antispasmodics acting on the level of microcirculation (trental, sermion, nicergoline, nicotinic acid, xanthinol) are prescribed. It is advisable to conduct magnetotherapy, electro- and laser-stimulation.