Quadrantanopia

Quadrantanopia (also spelled quadrantanopsia) is loss of vision in one quarter of the visual field. It affects the same quarter in both eyes (homonymous) and indicates damage to the brain's visual pathways—specifically the optic radiations or visual cortex.

Types of Quadrantanopia

Superior Quadrantanopia

Loss of the upper quarter of vision (right or left):

• "Pie in the sky" defect
• Damage to temporal lobe (Meyer's loop)
• Optic radiations passing through temporal lobe affected

Inferior Quadrantanopia

Loss of the lower quarter of vision (right or left):

• "Pie on the floor" defect
• Damage to parietal lobe
• Optic radiations in parietal lobe affected

Mnemonic

• Temporal lobe → Top field lost (superior quadrantanopia)
• Parietal lobe → lower (Pedestrian level) field lost (inferior quadrantanopia)

Causes

Stroke

• Most common cause
• Middle cerebral artery territory
• Posterior cerebral artery territory

Brain Tumor

• Primary brain tumors
• Metastatic tumors

Trauma

• Traumatic brain injury
• Surgical complications

Other

• Abscess
• Hemorrhage
• Demyelination (multiple sclerosis)

What Patients Experience

• May not notice the defect initially
• Missing part of the visual world
• Difficulty with:
  • Reading (if on the left)
  • Navigating stairs (if inferior)
  • Seeing overhead objects (if superior)
• May bump into objects

Diagnosis

Visual Field Testing

• Visual field test documents the defect
• Shows involvement of one quadrant
• Respects both horizontal and vertical midlines
• Present in both eyes (homonymous)

Brain Imaging

• MRI brain identifies the lesion
• Shows location in temporal or parietal lobe
• Helps determine cause (stroke vs. tumor vs. other)

Additional Workup

If stroke is the cause:

• Vascular imaging
• Cardiac evaluation
• Risk factor assessment

Treatment

Acute Management

If recent stroke:

• Emergency stroke protocols
• Prevent further damage

Rehabilitation

• Visual rehabilitation therapy
• Compensatory eye movement training
• Occupational therapy for daily tasks

Treat Underlying Cause

• Stroke prevention measures
• Tumor treatment if applicable
• Address other causes

Prognosis

• Some spontaneous recovery possible
• Most improvement occurs in first few months
• Complete recovery uncommon
• Can learn to compensate effectively

Comparison with Related Conditions

Finding	Location of Lesion
Quadrantanopia	Temporal or parietal lobe
Homonymous hemianopia	Occipital lobe or optic tract
Bitemporal hemianopia	Optic chiasm

Living with Quadrantanopia

Daily Adaptations

• Turn head to scan blind area
• Be aware of objects in affected quadrant
• Good lighting important
• May need to modify driving habits

Reading

• Line guides helpful
• Adjust text position
• Consider audiobooks

Driving

• Check local visual requirements
• May be allowed with quadrantanopia (varies by jurisdiction)
• Consider driving evaluation