Optic neuritis is a pathology that is characterized by the course of the inflammatory process in the optic nerve and damage to its tissue and membrane. Two forms of the disease are distinguished – intrabulbar and retrobulbar. More often, the disease develops against the background of fiber destruction caused by neurological disorders and causes deterioration in visual functions and several other symptoms.(1)
Does Optic Neuritis Show Up On MRI & Can Eye Test Detect It?
Symptoms of pinching of the optic nerve are characteristic of various pathologies, in connection with which this problem is considered in neurology and ophthalmology. To diagnose the disease, an ophthalmologist’s consultation is often enough. In this case, it is necessary to differentiate optical neuritis with other pathologies similar in symptoms.
Eye tests to check color vision, light responses, visual acuity and field of vision may help the ophthalmologist identify optic neuritis.
With minor lesions, the disease causes subtle changes in the structure of the disc and weak visual disturbances. In this case, fluorescence fundus angiography is required. With the help of this procedure, neuritis is differentiated with diseases of the optic nerve (congestive disc and others). Additionally, with a similar purpose, lumbar puncture and echo-encephalography are prescribed.
When developing treatment tactics, it is important to consider the characteristics of the cause of the disease. For its establishment, MRI of the brain, enzyme immunoassay, blood culture, and other examination methods are used. Anomalous findings in MRI are described in different studies. T2-weighted MRI images revealed that there is two or more occurrence of white matter lesions.(3)
How To Treat Optic Neuritis?
In the case of the detection of optic neuritis, treatment is started based on the condition or the causative factors diagnosed. If the disease develops against a background of viral infection, then antiviral drugs are included in the treatment regimen.
Subject to the identification of bacterial microflora, which caused inflammation of the optic nerve, antibiotics are used in the treatment. More often, the pathogen strain cannot be diagnosed, therefore, with optic neuritis; antibiotics are used that affect various forms of pathogens.
To reduce swelling of the optic disc, glucocorticosteroids are used. In the retrobulbar form of the disease, drugs of this type are injected through a syringe into the fiber located behind the eye. Intrabulbar neuritis is treated with general glucocorticosteroids.
An important condition for the successful recovery of the nerve during pinching in the eye is the intake of vitamins B1, B6, PP and drugs that improve blood microcirculation.(4)
The Affected Nerve Function
To represent the process of neuritis of the optic nerve, it is necessary to consider its structure and functions. It consists of axons of neurons that come from the retina. A nerve, consisting of more than 1 million fibers, transmits signals in the form of impulses to the visual center of the brain.
The area inside the retina, where the optic nerves are located, is called the intraocular (intrabulbar) region. The area in which the fibers pass into the cranium is known as the retrobulbar.
In neurology, the optic nerve performs several functions:
- It enables the eye to distinguish objects of various sizes (visual acuity);
- It provides the ability to distinguish colors;
- It defines the zone of visibility (the boundaries of the field of view).
If optic neuritis develops, then the functional abilities of the eye are simultaneously reduced. Neuritis of the eye cannot be completely cured. This is because a decrease in visual functions causes degeneration of nerve fibers that cannot be restored.(2)
Causes Of Optic Neuritis
The causes of optic neuritis in children and adults are mainly due to infection. Pathology can occur with:
- Keratitis, iridocyclitis and other eye diseases;
- Meningitis, encephalitis;
- Periostitis, phlegmon;
- Chronic tonsillitis, tonsillitis, sinusitis and other diseases of the nasopharynx.
Inflammation of the optic nerve is often observed with a complicated pregnancy and traumatic brain injuries. Prolonged alcoholism, diabetes mellitus, and blood pathologies, autoimmune diseases can provoke neuritis.
As a result of optical neuritis, visual acuity decreases. Moreover, over time, the intensity of the pathological process decreases and the functions of the eyes are restored. In advanced cases, the inflammatory process causes the breakdown of fibers, in place of which connective tissue is formed. Because of this, atrophy of the optic nerve occurs, which cannot be restored.
The risk group for developing neuritis of the eye includes people aged 20-40 years. More often the disease is diagnosed in women. A high risk of pathology is observed with multiple sclerosis. This pathology contributes to demyelination (destruction of the myelin sheath) of nerve fibers.(2)
- Cadavid D, Balcer L, Galetta S, et al. Safety and efficacy of opicinumab in acute optic neuritis (RENEW): a randomised, placebo-controlled, phase 2 trial. The Lancet Neurology. 2017;16(3):189-199.
- Bennett JL. Optic Neuritis. CONTINUUM: Lifelong Learning in Neurology. 2019;25(5):1236-1264.
- Stunkel L, Kung NH, Wilson B, McClelland CM, Van Stavern GP. Incidence and causes of overdiagnosis of optic neuritis. JAMA ophthalmology. 2018;136(1):76-81.
- Burton EV. Optic Neuritis: Clinical Manifestations, Pathophysiology, and Management. Neuroinflammation: Elsevier; 2018:337-353.