The optic nerve is a bundle of nerve fibers that carries image information from the eyes to the brain. You can compare it to an electrical wire that will not transmit current if it is damaged. Our brain and nervous system are made up of nerve and glial cells. When the glia has a defect and does not grow as it should, a tumor occurs – glioma of the optic nerve.
Why are children at risk?
For unknown reasons, most often (in 75% of cases) optic nerve gliomas develop before the age of 10 years, while in 30% of patients this diagnosis is combined with Recklinghausen’s disease, or type I neurofibromatosis . Glioma of the optic nerve may be secondary and occur in children after treatment for another malignant process. There is evidence that some genetic diseases are associated with the formation of glioma (Li – Fraumeni syndrome , Turco syndrome, tuberous sclerosis).
What are the clinical signs and symptoms of optic nerve glioma?
At the initial stage, there may be no manifestations of glioma, and children cannot always explain what worries them. Therefore, it is extremely important to undergo scheduled ophthalmological examinations, in which the doctor can notice the pathology. Due to compression and destruction of nerve fibers, as the tumor grows, the following is observed:
- Decreased visual acuity in one or both eyes;
- Headaches and nausea;
- Nystagmus – involuntary movements of the eyeballs;
- Appearance of cattle, narrowing of visual fields;
- Exophthalmos – protrusion or displacement of the eye to the side, limiting its mobility and incomplete closure of the eyelids;
- Vestibular ataxia (gait change, poor coordination);
- Drowsiness, changes in appetite and developmental delays due to hormonal disorders. A tumor in the optic nerve can affect the endocrine system.
Glioma of the optic pathways can appear anywhere on the optic nerve.
Depending on the localization, three types of tumors are distinguished:
- Intraorbital are located within the orbit;
- Intracranial – in the cranial part of the optic nerve;
- Gliomas of the chiasm – neoplasms in the region of the optic chiasm;
- Intracerebral, that is, grown into the structures of the brain.
Diagnosis and treatment
As a rule, exophthalmos becomes the main reason for visiting a doctor. To make a diagnosis, an ophthalmologist or optometrist performs visiometry and detects visual impairment, during perimetry – checking visual fields – blind spots may be found in the field of vision.
With ophthalmoscopy (examination of the fundus) at the initial stages of glioma development, changes may not be noticeable. At later stages, clinical manifestations of secondary atrophy of the optic nerve are observed. In this case, first of all, it is necessary to find out what concomitant pathology provoked malnutrition of nerve fibers.
Optic nerve atrophy is a condition in which the optic nerve is partially or completely damaged, and the connection between the brain and the eyeball is disrupted.
The disease can be similar to meningioma , angioma, neurinoma, retinoblastoma , orbital hemorrhage. To differentiate the diagnosis, you will need magnetic resonance imaging (MRI), computed tomography (CT), or targeted radiography, as well as consultation with an endocrinologist to rule out hyperthyroidism.
Gliomas tend to grow slowly, they are sensitive to chemotherapy and radiotherapy. Children under three years of age are usually prescribed the first type of treatment, as it has fewer side effects than radiation therapy. If the neoplasm is noticed at an early stage and treated in a timely manner, it will most likely be possible to stop the growth of the tumor and preserve visual function. The preferred treatment option is surgery. The operation can be effective even when vision is deteriorating too rapidly. Depending on the degree of damage, removal of the affected part of the optic nerve or enucleation (removal of the eyeball) is indicated, followed by prosthetics.
Sometimes doctors combine surgery and chemotherapy, for example, if the tumor cannot be completely removed. Combined treatment of optic tract gliomas can provide long-term remission due to the destruction of the remaining tumor cells.
Rehabilitation and prevention after treatment of optic nerve glioma
The survival rate of children diagnosed with optic nerve glioma is about 90%, and the probability of complete loss of vision is only 5%. Visual acuity at the time of diagnosis is the main factor in the success of treatment. Usually, the improvement of vision during therapy gives reason to make a prediction that after the end of the course it will be restored. Statistically, younger children are more likely to retain good vision after glioma treatment.
Even the most experienced and qualified doctor cannot guarantee that the disease will not return. That is why during the first six months it is necessary to regularly see a doctor to observe the dynamics and make sure that the disease has receded. Then you will need to visit an ophthalmologist every six months for another 2-3 years, and after that – at least once a year. The risk of blindness increases in cases where the tumor went unnoticed for too long and pressed on the optic nerve for more than six months. Recurrence can occur many years later, and usually the tumor appears in the same place. All this means that you need to keep your finger on the pulse all your life, even if there are no complaints after treatment.
If the child was treated with ionizing radiation or medication, it will be useful to undergo rehabilitation therapy to get rid of unpleasant consequences.
Due to illness and long-term treatment, children miss many classes at school, and cognitive functions may also decline, because not only malignant cells are damaged, but also all other body tissues. At this moment, the child needs the support and care of parents more than ever. Working with a psychologist, a rehabilitator, as well as a temporary transfer to home schooling can be very helpful in order to return his quality of life to its previous level.