Bitemporal hemianopsia is a specialized medical term that refers to one type of partial blindness. With this disease, the perception of the outer half of the left and right fields of vision falls out. In most cases, this pathology is associated with damage to the optic tract in the area where a partial intersection of the fibers of the optic nerves occurs. As a rule, this occurs in the pituitary gland with a characteristic defect of the temporal halves of the visual fields. This kind of ailment is referred to as heteronymous hemianopsia.
About the disease
By bitemporal hemianopsia is understood a visual impairment in which half of the visual field falls out in each eye. The appearance and development of this pathology is caused by the defeat of certain parts of the human vision system, including directly the part of the brain that is responsible for the process of visual perception.
Bitemporal hemianopsia in most cases is the result of the development of neoplasms that are localized in the central region of the intersection of the optic nerves. In the place where the fibers intersect from the inner halves of the retina. In this case, the temporal halves of the visual fields are turned off.
Causes
There are some of the most common causes of bitemporal hemianopsia and several other varieties of the disease, which will also be discussed in this article. In most cases, the development of this pathology is associated with the presence of the following conditions in the human body:
- neoplasms with localization inside the skull;
- basal meningitis;
- abscesses;
- circulatory disorders of the brain;
- severe skull injuries;
- aneurysms that lead to damage to the arteries of the brain.
Hemianopsia is observed in lesions of a certain part of the brain, and also appears against the background of craniopharyngiomas and tumors. Moreover, there is a likelihood of distortion of the optic tracts, which may be due to vascular aneurysms, growths of the pituitary gland, and defects of the temporal lobe. Hemianopsia is observed in the presence of neoplasms of the temporal and occipital lobes of the brain. It is able to radically change the work of the central neuron and cortical centers.
Summing up, it can be noted that bitemporal hemianopsia is observed with damage to the central region of the optic nerve intersection. The most common causes are hydrocephalic expansion of the funnel, a pituitary tumor.
Symptoms
This disease is characterized by well-defined symptoms, according to which it can be quickly recognized and proceed to timely treatment. In the event that the lesion is minor, the patient may have no complaints at all.
Such a pathology can be identified only during a routine examination with an ophthalmologist. However, such cases are still extremely rare. More often you can encounter situations when the symptoms are pronounced quite clearly.
Signs of disease
As a rule, patients with the occurrence of this ailment are disturbed by temporary blindness, which occurs due to the loss of certain fields of vision. In this case, the quality of life of the patient is significantly impaired. In particular, he loses the ability to read, watch TV, and in some cases even navigate in space.
Severe symptoms, as a rule, differ depending on the severity of the ongoing pathology. In the region of the fundus during examination, atrophy of the optic nerves often occurs, which leads to trauma to the chiasm.
Types of disease
Modern science identifies several types of this disease. In addition to bitemporal, there are other types of hemianopsia.
One of them is symmetric or homonymous hemianopsia. Being in this state, the patient is not able to distinguish between both right or left half of the visual field. In this case, the temporal half of the right eye and the nasal left of the left (or vice versa) fall out.
This condition in most cases becomes a consequence of damage to the optic tract. When the left optic tract is involved in the pathological process, they speak of right-sided hemianopsia. A typical and reverse situation: when the right tract is damaged, the patient does not see the left areas of the visual fields. In this case, left-sided hemianopsia is diagnosed.
Bilateral development of this disease is also possible. In this case, doctors diagnose contralateral hemianopsia. This is a specific neurological disorder characterized by bilateral blindness.
Heteronymous hemianopsia
A heteronymous variety of this disease occurs when both the temporal or nasal halves of the visual field are affected. In this case, a binasal or bitemporal heteronymous hemianopsia develops.
The causes of this particular condition are certain focal changes. This may be ischemia, hemorrhage, swelling, inflammation. They should occur in the pituitary gland, in the region of the base of the brain. In such situations, bitemporal hemianopsia is observed, which is a type of partial blindness. It is characterized by loss of perception of the temporal half of the right and left visual fields.
In fact, it is a type of hemianopsia, which is characterized by the loss of nasal fields of vision, both internal and medial. Bitemporal hemianopsia is observed in lesions of non-crossed fibers, against the background of inflammation of the arachnoid membrane of the brain.
If not half of the object, but only a smaller part of it falls out of the field of view, then one speaks of quadrant hemianopsia. In this case, only a quarter of the image becomes invisible.
Diagnostics
The diagnosis is made on the basis of the results of specific analyzes and studies. In particular, ophthalmoscopy, visual acuity, visual fields. It is important to understand that when analyzing the patient’s condition, the doctor is not always able to identify pathological changes. This is due to the fact that in the early stages, bitemporal temporal hemianopsia does not affect the condition of the fundus. Destructive changes appear approximately a year after the appearance of the first signs of pathology.
At the very beginning of the disease, visual acuity is not impaired at all. But if untreated, the disease goes to a later stage, since large areas of the optic nerves are affected. Then vision begins to deteriorate.
If the patient has homonymous or heteronymous hemianopsia, it is important to determine the exact cause of the occurrence and its variety as soon as possible. You can clarify the diagnosis using instrumental diagnostics. In this case, patients are prescribed angiography, computed tomography, brain ultrasound, x-ray, MRI.
If the disease is provoked by a tumor, a laboratory study should be performed to establish the presence of a particular hormone.
Control studies
It is important to differentiate this disease with pathologies such as decreased perception of certain colors, that is, hemichromatopsia, visual impairment in certain areas - hemihypoxia. These diseases may precede the occurrence of hemianopsia or develop on their own.
To establish the exact number of fields of view that fall out, perimetry is performed.
Additionally, control studies are prescribed, which can only be done by doctors with normal vision. For this, the patient and the doctor stand opposite each other at a distance of 10 centimeters. Their eyes must be located on the same level. Both survey participants cover one eye with a bandage or hand. The patient should carefully look into the open eye of the doctor.
The doctor begins to move his finger from the periphery to the central region, alternately in all directions. When the doctor’s finger appears in the patient’s field of vision, he must report it. If the doctor himself does not suffer from pathology, and his indicators coincide with the parameters of the subject, then the patient has normal vision. It is not difficult to identify this disease in this way.
Treatment
To determine the optimal therapy, it is important to establish the causes of the disease. If the patient is diagnosed with hemianopsia, he should additionally be sent for examination by a neurologist. He may also need the advice of an oncologist and a neurosurgeon. By eliminating the cause of the pathology, vision may improve somewhat.
Since the disease develops against the background of malignant tumors and pathologies, it is important to eliminate the primary sources of the problem. To this end, various treatment methods are used - chemotherapy, surgery, x-ray therapy.
Life Quality Tips
This disease is practically not amenable to conservative treatment; there are only recommendations that can improve the patient's quality of life. For example, you can facilitate reading by consciously increasing the size of small eye movements to one movement along the line itself. It should be read vertically, and the text should be kept at right angles.
With right-sided hemianopsia, you should read from top to bottom so that each next line is in the left field of view.
A number of computer techniques have also been developed that can improve the visual functions of patients. Using these training courses, you can partially compensate for lost vision, which will facilitate the patient's orientation in space.
After the diagnosis and the cause of the disease are accurately established, the doctor will be able to tell where to treat bitemporal hemianopsia.
Forecast
After treatment, vision can be restored completely, or it can be completely lost. It depends on many factors and primarily on the cause of the disease.
Here are the main ones:
- selected treatment tactics;
- the severity of the disease;
- duration of visual impairment;
- individual characteristics of the patient's body;
- the stage of the disease at which treatment is started;
- age of the patient;
- the presence of complications.
For example, after a stroke, restoration of the lost visual fields is possible in about six months.
Prevention
Using certain techniques, hemianopsia can be prevented. You can prevent this pathology with systematic consultations with an ophthalmologist and a neurologist. Due to the fact that the onset of the ailment is often directly related to brain tumors, scheduled examinations by specialists should be performed in order to timely detect neoplasms.
You can minimize the likelihood of hemianopsia, you only need to be careful about your health. It is important to prevent head injuries and brain injuries. Care should be taken about the condition of the heart and blood vessels, in order to prevent, undergo diagnostic tests of the body.
When the first alarming and suspicious symptoms appear, you should immediately consult a doctor. The sooner you are diagnosed, the faster you will be able to begin timely treatment. In this case, most likely, it will be possible to avoid complications, which will be much more expensive and more difficult to cope with.
When choosing a clinic in which you are going to treat hemianopsia, you should pay attention to its capabilities, whether effective and modern methods of therapy and appropriate diagnostic equipment are available. Important factors may be the qualifications of working specialists, the level of equipment of the clinic. After all, it will directly depend on the experience of doctors that you will be able to achieve a positive result.