Visual Field Deficits

Visual field deficits are areas of vision loss that create "blind spots" or missing portions in your field of view. Unlike overall blurred vision, these deficits affect specific regions while other areas remain clear. The pattern of visual field loss provides critical information about where the problem is located.

Understanding Your Visual Field

Your visual field is everything you can see without moving your eyes—about 180 degrees horizontally and 150 degrees vertically. Different parts of this field are processed by different structures:

• Retina (back of eye)—converts light to signals
• Optic nerve—carries signals from each eye
• Optic chiasm—where nerves partially cross
• Optic tract and radiations—pathways through brain
• Visual cortex (occipital lobe)—processes visual information

Damage at each level creates characteristic patterns of vision loss.

Types of Visual Field Deficits

Scotomas (Blind Spots)

• Central scotoma—blind spot in center of vision (macular or optic nerve disease)
• Paracentral scotoma—blind spot near but not at center
• Arcuate scotoma—arc-shaped defect (characteristic of glaucoma)
• Altitudinal defect—loss of upper or lower half of one eye's vision
• Cecocentral scotoma—enlarged blind spot connecting to central vision

Hemianopia (Half-Field Loss)

• Homonymous hemianopia—same side lost in both eyes (right or left)
  • Indicates damage behind the optic chiasm (brain)
• Bitemporal hemianopia—outer (temporal) fields lost in both eyes
  • Indicates damage at optic chiasm (often pituitary tumor)
• Binasal hemianopia—inner (nasal) fields lost (rare)

Quadrantanopia (Quarter-Field Loss)

• Superior quadrantanopia—upper quarter lost
• Inferior quadrantanopia—lower quarter lost
• Can be homonymous (same quadrant in both eyes)

Localizing the Problem

Pattern	Location	Common Causes
One eye only	Eye or optic nerve	Glaucoma, AION, optic neuritis
Bitemporal	Optic chiasm	Pituitary tumor, craniopharyngioma
Homonymous hemianopia	Opposite brain hemisphere	Stroke, tumor, injury
Homonymous quadrantanopia	Optic radiations	Stroke, tumor
Bilateral with macular sparing	Occipital cortex	Stroke (posterior cerebral artery)

Common Causes

Eye and Optic Nerve Causes

• Glaucoma—progressive nerve fiber loss causing arcuate defects
• Ischemic optic neuropathy—altitudinal defect
• Optic neuritis—central or cecocentral scotoma
• Retinal detachment—corresponding to detached area
• Branch retinal artery/vein occlusion—sectoral defect

Chiasmal Causes

• Pituitary adenoma—bitemporal hemianopia
• Craniopharyngioma—bitemporal field loss
• Meningioma—compressing chiasm
• Aneurysm—rare cause of chiasmal compression

Post-Chiasmal (Brain) Causes

• Stroke—most common cause of homonymous hemianopia
• Brain tumor—gradual onset hemianopia
• Traumatic brain injury—post-injury field loss
• Multiple sclerosis—demyelination in visual pathways
• Brain abscess or infection

When to Seek Care

How Visual Field Deficits Are Diagnosed

Visual Field Testing

• Automated perimetry (Humphrey)—standard computerized test
• Goldmann perimetry—manual kinetic testing
• Confrontation fields—quick bedside screening
• Frequency doubling technology (FDT)—screening tool

Eye Examination

• Visual acuity—checking central vision
• Pupil examination—looking for RAPD
• Dilated fundus exam—examining optic nerve and retina
• OCT—imaging nerve fiber layer

Neuroimaging

If pattern suggests brain cause:

• MRI brain—detailed brain imaging
• MRA/CTA—blood vessel imaging
• CT scan—for acute stroke evaluation

Treatment Options

Treatment depends entirely on the cause:

For Glaucoma

• Eye drops—lower intraocular pressure
• Laser treatment—improve drainage
• Surgery—if drops insufficient
• Goal: prevent further loss (vision usually doesn't return)

For Optic Nerve Causes

• IV steroids—for optic neuritis
• Tumor removal—for compressive causes
• Risk factor management—for ischemic optic neuropathy

For Chiasmal Causes

• Surgery—to remove pituitary tumor or other mass
• Radiation—sometimes used after surgery
• Medication—some pituitary tumors respond to drugs

For Stroke/Brain Causes

• Acute stroke treatment—if within treatment window
• Prevention—blood thinners, risk factor control
• Rehabilitation—visual field expansion training

Adaptive Strategies

For permanent visual field loss:

• Scanning training—learning to look toward blind area
• Prism glasses—some patients benefit
• Reading strategies—adjusting technique for hemianopia
• Mobility training—safe navigation
• Driving evaluation—formal assessment of safety

Living with Visual Field Loss

Safety Considerations

• Be aware of your blind side
• Turn head to scan environment
• Use caution with stairs and curbs
• Consider mobility training

Reading Adaptations

• For right hemianopia: text edge may be hard to find
• For left hemianopia: beginning of lines may be missed
• Use a straight edge or finger to track lines
• E-readers with adjustable formatting help

Driving

• Many states require minimum visual field for licensure
• May need formal driving evaluation
• Some people with stable hemianopia can drive safely with training
• Discuss restrictions with your doctor

Frequently Asked Questions

Can visual field loss be reversed?

It depends on the cause. Compression from a tumor may improve after removal. Stroke-related loss sometimes improves partially. Glaucoma damage is typically permanent. Treatment focuses on preventing further loss.

Why didn't I notice my visual field loss?

The brain compensates remarkably well, filling in gaps in vision. Gradual loss is especially hard to notice. Many people discover visual field deficits only during routine testing.

What's the difference between a scotoma and hemianopia?

A scotoma is an isolated blind spot (small area) while hemianopia is loss of half the visual field. Scotomas often indicate eye or optic nerve problems; hemianopia usually indicates brain involvement.

Can I still drive with visual field loss?

Possibly. Requirements vary by state, but most require a certain field width (often 120-140 degrees). A driving evaluation can determine if you can drive safely with your specific pattern of loss.

How often should my visual field be tested?

For glaucoma: typically every 6-12 months, or more frequently if progressing. For other conditions: as needed to monitor stability or response to treatment.

References