What is the therapy for peripheral field loss?

Therapy for Peripheral Field Loss

Scanning training to compensate for visual field loss is the recommended first-line therapy for peripheral field loss, with consideration of individual patient characteristics. 1

Understanding Peripheral Field Loss

Peripheral visual field loss affects approximately 13% of the population over 65 years and can significantly impact daily functioning 2. It can result from various conditions including:

• Glaucoma (affecting peripheral vision while typically sparing central vision)
• Acquired brain injury (such as stroke causing hemianopia)
• Retinitis pigmentosa
• Choroideremia

Impact on Daily Functioning

Peripheral field loss significantly affects quality of life through impairments in:

• Driving ability (especially lane maintenance)
• Reading speed and enjoyment
• Face recognition and social functioning
• Scene recognition and navigation
• Postural stability 3
• Pedestrian detection and collision avoidance 4

Rehabilitation Approaches

Three main approaches to peripheral field loss rehabilitation exist:

1. Compensatory Training (First-Line)

• Scanning training: Teaching patients to make systematic eye movements to compensate for the visual field defect
• Shown to positively impact quality of life compared to placebo or control 1
• Particularly beneficial for hemianopia field loss

2. Substitutive Interventions

• Peripheral prism eyeglasses: Can improve detection rates and reduce response times for pedestrian detection 4
• However, evidence suggests sector prisms for hemianopia may cause minor, frequent adverse events 1
• Limited evidence for generalized conclusions about effectiveness

3. Visual Restitution Therapy

• Aims to restore visual field function
• Insufficient evidence to reach conclusions about effectiveness compared to placebo or control 1

Specific Strategies for Reading with Hemianopia

For patients with hemianopia experiencing reading difficulties:

• Right hemianopia: Implement strategies to help see the end of longer words and subsequent words
• Left hemianopia: Use techniques to identify the beginning of the next line of text
• Practical approaches include:
  • Marking the left margin of text
  • Tilting text vertically
  • Practice with laterally scrolling text (limited evidence of effectiveness) 1

Multidisciplinary Approach

Visual deficits from acquired brain injury often require a multidisciplinary approach including:

• Ophthalmology
• Occupational therapy
• Neurology
• Vision rehabilitation specialists

Recovery and Outcomes

Recovery from peripheral field loss varies:

• Complete recovery: ~7.5% of patients
• Partial improvement: ~39% of patients
• No recovery: ~52% of patients 5

Clinical Recommendations

1. Perform comprehensive visual field testing to accurately define type and extent of loss
2. Diagnose coexistent visual impairments that may accompany peripheral field loss
3. Implement compensatory scanning training as first-line therapy
4. Consider peripheral prism eyeglasses for specific cases where detection of objects in the blind field is critical
5. Provide practical strategies for reading and daily activities based on the specific pattern of field loss
6. Regular follow-up to monitor for changes in visual field and effectiveness of interventions

Caution

The evidence for interventions in peripheral field loss rehabilitation is generally of low to moderate quality 1. While compensatory scanning training shows the most promise, more research is needed to establish optimal protocols and long-term effectiveness.