Visual Field Defects

Definition | Types | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Visual field defects refer to a partial or complete loss of the field of vision, which can affect one or both eyes. These defects can result from a variety of ocular and neurological conditions.

Types

Visual field defects can be classified into several types based on their location and extent, including:

• Central scotoma: Loss of central vision
• Peripheral field loss: Loss of peripheral vision
• Hemianopia: Loss of half of the visual field in one or both eyes (e.g., homonymous hemianopia)
• Quadrantanopia: Loss of a quarter of the visual field
• Altitudinal field defects: Loss of vision in the upper or lower half of the visual field

Aetiology

Visual field defects can result from various causes, including:

• Glaucoma
• Retinal diseases (e.g., retinal detachment, age-related macular degeneration)
• Optic nerve disorders (e.g., optic neuritis, optic neuropathy)
• Brain lesions (e.g., strokes, tumours, trauma)
• Systemic diseases (e.g., diabetes, hypertension)

Pathophysiology

The pathophysiology of visual field defects depends on the underlying cause. Damage to the retina, optic nerve, or visual pathways in the brain can disrupt the transmission of visual information, leading to specific patterns of field loss.

Risk Factors

• Age (increased risk with advancing age)
• Family history of eye diseases
• Chronic diseases (e.g., diabetes, hypertension)
• Trauma to the head or eyes
• Exposure to toxins or radiation

Signs and Symptoms

Common signs and symptoms of visual field defects include:

• Partial or complete loss of vision in a specific area of the visual field
• Difficulty seeing objects in peripheral vision
• Blurred or distorted vision
• Double vision
• Difficulty with coordination and balance

Investigations

• Clinical history and physical examination
• Visual acuity test
• Visual field testing (perimetry)
• Fundoscopy to examine the retina and optic nerve
• Imaging studies (e.g., MRI, CT scan) to identify brain lesions or other structural abnormalities
• Blood tests to check for systemic conditions

Management

Primary Care Management

• Immediate referral to an ophthalmologist or neurologist: For further evaluation and management
• Management of underlying conditions: Such as controlling blood sugar levels in diabetes or blood pressure in hypertension

Specialist Management

• Treatment of the underlying cause:
  • Medications for glaucoma or retinal diseases
  • Surgical intervention for retinal detachment or brain tumours
  • Rehabilitation therapy for visual field loss
• Regular monitoring: Follow-up appointments to monitor the progression and response to treatment

References

1. NICE. (2024). Visual Field Defects: Diagnosis and Management. Retrieved from NICE
2. NHS. (2023). Visual Field Defects. Retrieved from NHS
3. British Medical Journal (BMJ). (2022). Visual Field Defects: Diagnosis and Management. Retrieved from BMJ
4. American Academy of Ophthalmology (AAO). (2021). Clinical Practice Guidelines: Visual Field Defects. Retrieved from AAO

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