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Our visual field refers to the entire area we can see without moving our head. Vision loss occurring in one half of this field is called hemianopsia (or hemianopia). Hemianopsia is a neurological visual disorder resulting from damage in the brain’s visual pathways or visual cortex, rather than the eyes themselves. This condition can significantly affect an individual’s daily living activities, mobility, reading skills, and overall quality of life. Early diagnosis of hemianopsia, which can occur in both children and adults, along with the determination of the underlying cause and the development of appropriate rehabilitation strategies, is of great importance.
Hemianopsia: We understand the effects of complex neuro-ophthalmological conditions like this, especially in pediatric patients, and aim to support our patients and their families with accurate diagnosis and appropriate guidance. We will cover in detail what hemianopsia is, its types, causes, symptoms, diagnostic methods, and current vision rehabilitation approaches.
Table of Contents
What is Hemianopsia?
Hemianopsia literally means “half vision.” It refers to the loss of vision that occurs in the right or left half of the visual field, and sometimes in the upper or lower half. This loss usually affects both eyes, and the affected half of the visual field is symmetrical (e.g., the right half of both eyes). Hemianopsia results from damage occurring in the brain’s visual pathways after the optic nerves (optic chiasm, optic tract, lateral geniculate nucleus, optic radiations) or directly in the brain’s visual cortex (occipital lobe).
The eyes collect information, but the brain is where this information is processed and made sense of. Therefore, any disruption in the visual pathways prevents the perception of the part of the visual field for which that area of the brain is responsible.
Types of Hemianopsia
Hemianopsia is classified according to the affected area of the visual field and the location of the damage in the visual pathways. The most common types are:
| Type of Hemianopsia | Description | Typically Affected Brain Region |
|---|---|---|
| Homonymous Hemianopsia | Loss of vision on the same side (right or left) of the visual field in both eyes. For example, both eyes cannot see objects on the right side. This is the most common type. | Visual pathways after the optic chiasm (optic tract, lateral geniculate nucleus, optic radiations, visual cortex – vision loss usually occurs on the side opposite the damage). |
| Heteronymous Hemianopsia | ||
| – Bitemporal Hemianopsia | Loss of vision in the outer (temporal) halves of the visual field in both eyes. Can cause a “tunnel vision” appearance. | The center of the optic chiasm (e.g., pituitary tumor compression). |
| – Binasal Hemianopsia | Loss of vision in the inner (nasal) halves of the visual field in both eyes. Rarely seen. | Compression on both lateral (side) parts of the optic chiasm (rare). |
| Quadrant anopsia | Loss of vision in one quarter (one quadrant) of the visual field. For example, loss in the upper right quadrant of both eyes (homonymous superior quadrantanopsia). | Partial damage to the optic radiations or visual cortex (e.g., superior quadrant loss in temporal lobe lesions, inferior quadrant loss in parietal lobe lesions). |
| Altitudinal Hemianopsia | Loss of vision in the upper or lower half of the visual field. | Usually originates from the optic nerve or retina, but can sometimes be seen in bilateral occipital lobe lesions. |
This classification assists clinicians in determining the location of the damage and understanding the underlying cause.
Causes of Hemianopsia
There are many different neurological conditions that can lead to hemianopsia. While the causes can be similar in children and adults, some conditions may be more frequent in certain age groups.
Common Causes in Adults:
- Stroke: The most common cause of hemianopsia. It develops especially as a result of blockage (ischemic stroke) or bleeding (hemorrhagic stroke) in the blood vessels supplying the brain’s visual pathways or visual cortex.
- Brain Tumors: Benign or malignant tumors that press on or spread to the visual pathways or visual center.
- Head Trauma (Traumatic Brain Injury – TBI): Severe head injuries that particularly affect the occipital lobe.
- Complications of Brain Surgery: Damage may occur during surgeries performed near the visual pathways.
- Demyelinating Diseases like Multiple Sclerosis (MS): Damage to the myelin sheath of the nerves in the visual pathways.
- Aneurysms or Arteriovenous Malformations (AVM): Through compression or bleeding.
Possible Causes in Children:
- Pediatric Stroke: Stroke can also occur in children and cause hemianopsia.
- Brain Tumors: Childhood brain tumors (e.g., craniopharyngiomas, gliomas) can compress the visual pathways.
- Head Traumas: As a result of falls or accidents.
- Hydrocephalus: Excessive fluid accumulation in the brain and resulting increased pressure.
- Cerebral Palsy (CP): Brain damage causing CP can also affect the visual pathways.
- Infections: Central nervous system infections such as meningitis, encephalitis.
- Congenital Brain Anomalies: Developmental disorders of the brain.
- Hypoxic-Ischemic Injury: Lack of oxygen supply to the brain during or after birth.
Dr. Semrin Timlioğlu emphasizes the importance of a multidisciplinary approach for the careful investigation of the causes of hemianopsia, especially in children, and the correct management of the underlying condition.
Symptoms of Hemianopsia
Individuals who develop hemianopsia may not immediately realize that they have lost half of their visual field. The brain may try to “fill in” the missing information, or the person may try to compensate for the condition. However, various difficulties emerge over time.
| Symptom Category | Observable Signs and Difficulties Experienced |
|---|---|
| Mobility and Safety | Bumping into objects, door frames, or people on the side of the missing visual field. Difficulty going up and down stairs, increased risk of falling. Difficulty navigating crowded environments. |
| Reading and Writing | Difficulty finding the beginning or end of a line while reading, skipping lines, seeing only half of words. Overlapping the edge of the line or inability to write in a straight line when writing. |
| Daily Living Activities | Inability to see and eat a portion of food on the plate. Difficulty finding objects on the missing side (e.g., inability to locate a glass on the table). Forgetting to dress one side of the body. |
| Social Interaction | Failing to notice people approaching from the missing side, thus appearing unresponsive or rude. Difficulty following conversations in a group. |
| Driving (Adults/Permitted Situations) | Difficulty staying in the lane, difficulty checking side mirrors or traffic on the missing side (driving with hemianopsia is usually unsafe and may be subject to legal restrictions). |
| Visual Search and Attention | Inadequate scanning of the missing visual field when searching for a specific object or person. Difficulty noticing details in a visually complex scene. |
| Compensatory Behaviors | A tendency to constantly turn the head or eyes towards the side of the missing visual field. |
| Additional Symptoms in Children | Neglecting toys on one specific side while playing. Inability to see a part of the blackboard at school, learning difficulties. Using only one half of the page when drawing or painting. Unexpected clumsiness or coordination problems. |
These difficulties can negatively affect the person’s independence, self-confidence, and social participation.
Diagnosis of Hemianopsia
Hemianopsia is diagnosed through a comprehensive eye examination and neurological evaluation. Dr. Semrin Timlioğlu conducts the diagnosis process with sensitivity, especially in pediatric patients. Steps in the Diagnosis Process:
- Detailed Anamnesis (Patient History): Inquiry is made into when and how the symptoms started, other accompanying complaints (headache, dizziness, speech disorder, etc.), and underlying diseases (history of stroke, tumor, or trauma). Birth history and developmental milestones are important in children.
- Visual Acuity Assessment: The visual acuity of each eye is measured separately. Hemianopsia may not directly affect central visual acuity, but the underlying cause (e.g., optic nerve damage) might.
- Comprehensive Eye Examination: Eye movements, pupillary function, anterior segment, and fundus (optic nerve head and retina) are examined. Findings such as papilledema (optic nerve head swelling) or optic atrophy (optic nerve pallor) may indicate underlying increased intracranial pressure (ICP) or nerve damage.
- Visual Field Tests (Perimetry): This forms the basis of the hemianopsia diagnosis. These tests map the areas where the patient can see and where vision loss occurs.
- Confrontation Visual Field Test: A simple test during the examination where the doctor assesses the patient’s awareness by moving their fingers or an object in different visual field quadrants. It is used for initial assessment, especially in small children or patients with difficulty cooperating.
- Automated (Computerized) Perimetry (Humphrey, Octopus): A standardized, precise, and quantitative measurement test. The patient looks into a hemisphere and presses a button when they see light stimuli appearing at different points.
- Goldmann Kinetic Perimetry: A manual test where the boundaries of the visual field are mapped using moving light stimuli. It is useful for assessing peripheral visual fields and irregular losses.
- Modified Tests for Children: Engaging toys or special test patterns may be used for small children.
- Neurological Examination: The patient’s general neurological status, other cranial nerve functions, and other possible signs of brain damage are assessed by a neurologist.
- Brain Imaging Methods:
- Magnetic Resonance Imaging (MRI): The gold standard for showing brain tissue, visual pathways, and possible lesions (stroke, tumor, trauma, inflammation) in detail.
- Computed Tomography (CT): Provides rapid information, especially in cases of acute bleeding or bone trauma.
As a result of these evaluations, the type, degree of hemianopsia, and most importantly, the underlying cause are determined.
Hemianopsia Treatment and Vision Rehabilitation
The primary goal in hemianopsia treatment is to treat the underlying cause. For example, if there is a brain tumor, surgery, radiotherapy, or chemotherapy may be applied; after a stroke, risk factors are controlled, and rehabilitation begins. When the underlying cause is treated, partial or complete improvement in the visual field can sometimes be seen.
However, if the damage to the brain tissue is permanent, hemianopsia is usually permanent as well. In this case, treatment focuses on helping the patient make the best use of their existing vision and cope with daily life challenges through vision rehabilitation and compensatory strategies.
Vision Rehabilitation Strategies:
- Scanning Training: The patient is taught to consciously turn their head and eyes toward the side of the missing visual field to effectively scan their surroundings. This can increase the ability to notice obstacles and move safely.
- Compensatory Strategies:
- Using a colored ruler or finger to find the beginning or end of a line while reading.
- Always placing objects on the seeing side.
- Consciously directing more attention toward the blind side when walking or entering a new environment.
- Making adjustments at home and in the working environment (fixing the location of objects, ensuring good lighting, increasing contrast).
- Prismatic Glasses: In some cases, special prismatic glasses (e.g., yoked prisms, peripheral prisms) can help by slightly shifting the visual field toward the missing side or increasing peripheral awareness. However, their effectiveness varies from person to person and requires expert evaluation.
- Reading Aids: Methods such as magnifiers, line guides (typoscopes), and adjusting the font size and contrast on e-readers can make reading easier.
- Computer-Based Rehabilitation Programs: Some programs offer exercises aimed at improving visual search, attention, and scanning skills.
- Multidisciplinary Approach: A team consisting of an ophthalmologist, neurologist, physical therapist, occupational therapist, speech therapist (especially if alexia is present), and psychologist can create a comprehensive rehabilitation program tailored to the patient’s needs.
- Educational Support for Children: Support such as special seating arrangements in school, adaptations in curriculum materials, and extra time should be provided. It is crucial to inform teachers and the family about the child’s visual difficulties.
Dr. Semrin Timlioğlu monitors pediatric and adult patients diagnosed with hemianopsia, guides families on appropriate rehabilitation options, and contributes to the treatment process as part of the multidisciplinary team.
Hemianopsia is a condition that can significantly affect life. However, with correct diagnosis, treatment of the underlying cause, and effective vision rehabilitation strategies, it is possible for individuals to increase their independence and improve their quality of life. If you notice a sudden or progressive loss in your visual field, it is vital to consult an ophthalmologist and a neurologist immediately.
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