What are the management strategies for different types of hemianopia?

Management Strategies for Different Types of Hemianopia

Compensatory scanning training is the recommended first-line treatment for hemianopia, with consideration of individual patient characteristics. 1

Types of Hemianopia and Their Characteristics

Hemianopia refers to loss of vision in half of the visual field and can be classified as:

• Complete hemianopia: Total loss of vision in half of the visual field
• Partial hemianopia: Incomplete loss of vision in half of the visual field
• Bilateral hemianopia: Vision loss affecting both sides of the visual field 2

Hemianopia commonly results from:

• Stroke (69.6%)
• Traumatic brain injury (13.6%)
• Brain tumors (11.3%)
• Other causes including brain surgery, demyelination (4%) 3

Assessment Approach

• Conduct a thorough visual field examination to determine:

  • Type of hemianopia (complete vs. partial)
  • Presence of macular sparing
  • Congruity of the defect (similar pattern in both eyes)
  • Associated neurological signs (nystagmus, internuclear ophthalmoplegia, Horner's syndrome) 1

• Evaluate functional impact on:

  • Reading ability (especially right hemianopia affecting word completion)
  • Navigation safety
  • Daily activities
  • Quality of life 1

Management Strategies by Rehabilitation Approach

1. Compensatory Training (First-Line Approach)

• Scanning Training:

  • Teaches systematic eye movements to compensate for field loss
  • Has moderate quality evidence supporting its use
  • Improves quality of life compared to placebo or control 1
  • Requires less practice time than other approaches 4

• Reading Strategies:

  • For right hemianopia: Focus on seeing the end of longer words
  • For left hemianopia: Mark the left margin of text or tilt text vertically
  • Practice with laterally scrolling text to improve reading speed and accuracy 1

2. Substitution Approaches

• Peripheral Prism Eyeglasses:

  • Can expand the visual field
  • Low quality evidence shows they may cause minor, frequent adverse events
  • Insufficient evidence for generalized conclusions about effectiveness 1

• Optical Therapies:

  • Bring the damaged visual field into view using optical devices
  • Require significant practice to be effective 4

3. Visual Field Restitution

• Vision Restoration Therapy:
  • Aims to improve vision in the damaged field itself
  • Insufficient evidence to reach generalized conclusions about effectiveness
  • Requires many hours of practice 1, 4
  • Motion discrimination training has not shown difference between treatment and control 1

Special Considerations for Different Types

For Right Homonymous Hemianopia:

• Patients have difficulty seeing the end of longer words and subsequent words
• Disrupts reading saccade pattern
• Focus on strategies to improve reading accuracy and speed 1

For Left Homonymous Hemianopia:

• Patients have difficulty identifying the beginning of the next line of text
• Mark the left margin of text or tilt text vertically to assist 1

For Acute Hemianopia from Stroke:

• Consider IV thrombolysis if within treatment window (up to 4.5 hours from symptom onset)
• Early intervention may improve outcomes and potentially restore visual field 5

Multidisciplinary Approach

• Occupational Therapy:

  • Essential component of rehabilitation
  • Addresses motor, language, and cognitive deficits that may accompany hemianopia
  • Helps with environmental modifications and assistive technology 1, 2

• Referrals to Specialized Services:

  • State services for the visually impaired
  • Orientation and mobility specialists
  • Vision rehabilitation specialists 2

Prognosis and Follow-up

• Spontaneous recovery may occur within the first few months after onset
• Regular follow-up is essential to monitor for improvement
• If no spontaneous recovery occurs, rehabilitation methods become crucial 6

Common Pitfalls and Caveats

• Terminology confusion: Vision rehabilitation is distinct from "vision therapy" used for other conditions 1
• Cost and accessibility: Rehabilitation may be intensive and pose healthcare costs and challenges for patients to attend treatment 1
• Evidence limitations: Many studies have methodological deficiencies, and larger controlled trials are needed 1, 7
• Unrealistic expectations: Patients seeking complete restoration of vision may be disappointed; focus on functional improvement rather than cure 1

By implementing these management strategies, patients with hemianopia can maximize their remaining vision, improve their quality of life, and regain independence in daily activities.