Homonymous hemianopsia: how it affects stroke patients

Homonymous hemianopsia is a partial loss of vision affecting the same side of the visual field in both eyes, and it is a common complication following a stroke. This symptom can significantly reduce quality of life, making everyday tasks such as reading, walking, or recognizing objects and people more difficult.

What is homonymous hemianopsia?

Homonymous hemianopsia refers to the loss of vision on the same side of the visual field in both eyes. For example:

• In right homonymous hemianopsia, vision is lost in the right half of both eyes.
• In left homonymous hemianopsia, the same occurs but on the left side.

This occurs due to damage to the optic tract, optic radiations, or the occipital lobe—structures responsible for processing visual information.

Relationship between homonymous hemianopsia and strokes

Both ischemic and hemorrhagic strokes are the leading cause of homonymous hemianopsia. This is because the blood supply to brain areas involved in vision, such as the occipital lobe, can be disrupted during a stroke.

1. Stroke in the posterior cerebral artery:
   • It is one of the most common causes, as this artery supplies the occipital lobe, where visual stimuli are processed.
2. Lesions in the optic tract:
   • If damage occurs in this region, visual information from both eyes is lost on the affected side.
3. Impact on quality of life:
   • Patients often experience difficulties with orientation, reading, writing, or performing daily activities due to this visual loss.

Causes of homonymous hemianopsia

In addition to strokes, other causes include:

• Brain tumors:
  • They can compress the optic radiations or the occipital lobe.
• Traumatic brain injuries:
  • Injuries to the back of the brain can affect vision.
• Brain infections:
  • Conditions such as encephalitis or brain abscesses.
• Neurodegenerative disorders:
  • Certain diseases, such as multiple sclerosis, can damage the visual pathways.

Symptoms of homonymous hemianopsia

Symptoms may vary depending on the cause and extent of brain damage. The most common ones include:

• Loss of vision in half of the visual field in both eyes.
• Difficulty detecting objects on the affected side.
• Orientation and balance problems, especially in unfamiliar environments.
• Visual fatigue when reading or performing prolonged visual tasks.
• Frequent collisions with objects or people on the affected side.

Diagnosis of homonymous hemianopsia

Diagnosis typically involves a multidisciplinary approach:

1. Medical history and neurological examination:
   • Identify symptoms and history of stroke or other conditions.
2. Visual field testing:
   • An examination that assesses the patient’s visual field, detecting areas of loss.
3. Brain imaging:
   • Magnetic resonance imaging (MRI) or computed tomography (CT) to locate brain damage.
4. Ophthalmological evaluation:
   • To rule out direct eye problems that may contribute to visual loss.

Treatment of homonymous hemianopsia

There is no treatment that completely reverses homonymous hemianopsia, but available options help improve the patient’s quality of life:

1. Visual rehabilitation:
   • Programs designed to train patients to compensate for visual loss using the unaffected part of the visual field.
2. Therapies with optical prisms:
   • Special glasses that expand the visual field by redirecting light rays toward the unaffected area.
3. Visual scanning exercises:
   • Techniques to train the patient to move their eyes more efficiently and scan the affected side.
4. Assistive technology:
   • Apps and devices that assist with orientation and reading.
5. Treatment of the underlying cause:
   • In cases of tumors, infections, or inflammation, directly addressing these conditions can prevent further progression.

Living with homonymous hemianopsia

Adapting to homonymous hemianopsia can be challenging, but the following strategies can help ease daily life:

• Organize the environment:
  • Keep important objects in accessible and visible locations.
• Use of visual aids:
  • Such as magnifiers or enlarged screens.
• Learn visual scanning techniques:
  • Train eye movement to scan the affected side.
• Psychological support:
  • Manage the emotional impact of visual loss with therapy or support groups.

Prevention of homonymous hemianopsia in stroke

Reducing the risk of stroke is key to preventing homonymous hemianopsia. This includes:

• Controlling risk factors such as high blood pressure, diabetes, and high cholesterol.
• Adopting a healthy lifestyle with a balanced diet and regular exercise.
• Avoiding tobacco use and excessive alcohol consumption.
• Having regular medical check-ups to detect cardiovascular problems early.

Conclusion

Homonymous hemianopsia is a significant neurological complication, especially in patients who have suffered a stroke. Although visual loss may be permanent, rehabilitation strategies and comprehensive management allow patients to regain some independence and improve their quality of life.

Investing in stroke prevention and in education about the symptoms and treatment of homonymous hemianopsia can make a crucial difference in the lives of those facing this condition.

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