What Is Hemianopsia?
Hemianopia, also known as hemianopsia, is a condition characterized by partial blindness or loss of sight in half of the visual field. It is caused by a brain injury rather than a vision issue. A stroke, a tumor in the brain, or a traumatic brain injury often cause this syndrome.
Hemianopsia can be severely disabling, limiting the patient's ability to navigate their environment, read, and drive a vehicle. As a result of its effect on the visual system, this illness frequently causes lower productivity and increased morbidity. Thus, understanding the functional architecture of the visual field pathways and corresponding visual fields, in addition to carefully analyzing the patient's medical history and physical exam, can help to localize pathological lesions in the central nervous system.
What Causes Hemianopsia?
Because the blood inside the brain has nowhere to go, bleeding inside the brain is harmful. Blood clots can push against the brain and cause harm over time. Damage to brain parts connected to vision can also result in hemianopsia and many other brain diseases. A few of these ailments are hazardous or potentially fatal. Others are rather insignificant, and there is little chance of long-term harm.
Brain damage might also be brought on less frequently by
Hemianopsia may develop from injury to the following:
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Optic chiasm.
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Optic nerves.
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Brain areas are involved in vision processing.
What Are the Types of Hemianopsia?
Hemianopia can be classified into several categories based on the brain regions involved.
The brain has two halves:
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Left Side - This half takes in information from both eyes, interprets it, and transmits signals that allow people to see the correct side of the visual environment.
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Right Side - This half collects and processes information from both eyes before sending signals that allow people to perceive the left side of the visual world.
Types of hemianopsia:
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Bitemporal Hemianopsia: An optical condition that causes diminished peripheral vision in each eye's outer temporal halves. This disorder is typically caused by a tumor or lesion that affects the optic chiasm, the area of decussation for the optic nerve responsible for visual input from the nasal retina in each eye.
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Binasal Heminopsia: It is a rare disorder that usually manifests in partial form. Possible causes are bilateral internal carotid artery aneurysms, hydrocephalus in intracranial mass lesions, neurosyphilis (an infection involving the CNS), and increased intracranial pressure.
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Homonymous Hemianopsia: It is a visual field defect that impacts both eyes' right or left portions of the visual fields. Complete homonymous hemianopsia involves the whole hemifield of both eyes. A lesion at any point along the retrochiasmal visual pathway causes this syndrome. The other lesions are characterized as incomplete.
What Are the Symptoms of Hemianopsia?
The symptoms of hemianopsia are:
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Walking and running into things like door frames, furniture, and people feeling like the vision has a problem.
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Driving difficulties, particularly while attempting to avoid vehicles on the side of the road or while changing lanes.
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Perceiving unseen lights or forms.
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Finding or accessing items on counters, desktops, or cupboards and closets takes a lot of work.
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Visual hallucinations (a false perception of objects), which afflicted people may experience in their blind field. The sufferers might not be aware that their perceptions are illusory.
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Losing place while reading a lot or finding it difficult to determine when a line of text begins or ends.
How Is Hemianopia Diagnosed?
Formal visual field perimetry testing is an important tool for analyzing the visual field with increased sensitivity because it goes beyond the constraints of confrontation testing alone. Depending on the results of the checkup, the doctor may perform imaging tests to examine the back of the eye.
They may also inject small bursts of air into the eyes to measure the pressure within them. These tests will assist the doctor in ruling out any other potential causes for the eyesight problem. The confrontation test is a straightforward and effective way to measure the visual field. This test has a limited sensitivity, ranging between 35 % and 74 %. Neuroimaging and physical examination results can identify the underlying cause of hemianopsia and assist clinical therapy.
What Is the Treatment for Hemianopsia?
The results of imaging scans and physical examinations should guide clinical care. Patients with cerebral hemorrhage or infarction (obstruction of blood supply to an organ) should be treated with specialized care. Patients with mass lesions or indications of elevated intracranial pressure might need to be admitted to the hospital for medicinal or surgical therapy. When necessary, consultation with neurologists and neurosurgeons is recommended. If blood flow is restored, hemianopsia may improve in certain patients. Though hemianopsia is typically irreversible in cases of brain neurological injury, eye specialists may still be able to suggest other solutions.
What Are the Complications of Hemianopsia?
Hemianopsia complications can significantly negatively influence a patient's quality of life. These complications can include poor balance, an increased risk of falls and injuries, loss of independence, difficulty reading, impaired visual scanning, depression, and fewer work opportunities.
Conclusion:Patients suffering from hemianopsia find it difficult to navigate their surroundings and carry out daily activities, including writing, reading, and driving. Patients and medical personnel can ignore visual field abnormalities. Therefore, to locate lesions in the central nervous system, doctors must also be able to interpret the results of visual field tests with proficiency and accuracy. To recognize hemianopsia and identify potential anomalies, clinicians must be extremely vigilant. Individuals with deficiencies in their visual fields may experience anxiety and depression. Within the healthcare team, psychological and social assistance are vital.
