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Neuro-Ophthalmic Visual Fields

There are basically 3 kinds of neuro-ophthalmic fields:

1) Central scotoma Optic nerve

2) Bitemporal heteronymous quadrant/hemianopia Chiasm

3) Homonymous quadrant/hemianopia Post chiasm

1. "Best" Visual Fields

Automated perimetry is more reproducible, however, may be difficult for patient to perfrom. Goldmann perimetry should be reserved for those patients who perform perimetry unreliably or where examination of the peripheral visual field is important.

Goldmann Perimetry:

• Always do three isopters to map out the hill of vision.

• Central vision is always affected first with neurological conditions and may only be detected up with a small intensity target

2. Constricted Visual Fields

There are only three causes

1. Bilateral peripheral retinal disease
2. Bilateral homonymous hemianopias secondary to bilateral occipital lobe disease
3. Hysteria or malingering

1) and 2) will have funnel vision and 3) will have tubular vision and other functional deficits.

• If find constricted visual fields
• ALWAYS perform tangent perimetry at 1 and 2 m
• as tubular visual constriction proves field loss is non-organic or functional

3. Papilloedema

Automated perimetry is more reproducible, however, may be difficult for patient to perfrom. Goldmann perimetry should be reserved for those patients who perform perimetry unreliably or where examination of the peripheral visual field is important.

• Visual field loss is usually first seen inferonasally. This is also true for Vigabatrin.