The document discusses visual fields, defining them as the area visible in peripheral vision. It classifies visual field defects into categories related to glaucomatous and neurological conditions, detailing their causes and characteristics, such as scotomas and their association with optic nerve diseases. The document outlines the visual pathway and how lesions affect visual perception, highlighting specific visual field loss patterns associated with various conditions.

1. Visual Field
Def, types, Classification, neurological and
glaucomatous visual fields
MARYAM FIDA
Optometry and Orthoptics

2. Visual Field
The visual field refers to the total area in which objects can be seen in the side
(peripheral) vision as you focus your eyes on a central point.
OR
The island of vision surrounded by a sea of blindness is known as visual field.
Normal fieldof vision
upwards = 60
inwards = 60
downwards = 70
outwards = > 90
Normal visual field
The island of vision surrounded by a sea of blindness is known as visual field.
Point of fixation
Area of maximum VA in normal visual field.
It corresponds to fovea of retina.
Blind spot
Area of absolute scotoma within the boundaries of normal VF.
It corresponds to optic nerve head where no rods and cones are present.
Locate 15° temporal to point of fixation.
60°
60°
70°
>90°
Figure 2 Right eye Figure 1 left eye
>90°
60°
60°
70°

3. Overview of visual pathway

4. Glaucomatous Visual Fields Neurological Visual Fields
Result from lesions of nerve fiber bundles
1. Toxic amblyopia
Bilateral Central scotoma_ as in tobacco amblyopia,
alcohol amblyopia, nutritional amblyopia, lead
poisoning or digitalis toxicity
Peripheral depression_
Contraction_ as in poisoning by quinine, arsenic,
chloroquine or salicycate.
Centrocecal scotoma_ scotoma of tobacco or alcohol
amblyopia
Figure 3 optic nerve head in optic neuropathies
Defects occur as a result of diminished blood flow in
anterior optic nerve in region of lamina cribrosa,
arterial circle of zinn-Haller and peripapillary choroidal
circulation.
2. Optic nerve diseases
Optic neuritis_ is an inflammation of the optic nerve.
Causes include infections and immune-related illnesses
such as multiple sclerosis. Sometimes the cause is
unknown.
Optic nerve atrophy_ is damage to the optic nerve.
Causes include poor blood flow to the eye, disease,
trauma, or exposure to toxic substances.
Optic nerve head drusen_ are pockets of protein and
calcium salts that build up in the optic nerve over time.
Figure 4 Optic neuritis

5. Blind spot & Bjerrum scotoma: in early stage of Open-
angle glaucoma, defect may occur in form of vertical
extension of blind spot.
Or a fiber bundle scotoma extends above or below
fixation to horizontal midline in nasal field (Bjerrum
scotoma).
3. The optic chiasm
Double Bjerrum scotoma: In later stage of glaucoma,
Double Bjerrum scotoma may present (one in upper
field and one in lower field).
The two coming together at horizontal midline and
forming a nasal step.
4. The post chiasmal pathway
Optic tract_ Contralateral homonymous hemianopsia
Lateral geniculate nucleus (LGN)_
Contralateral homonymous hemianopsia
Optic radiations_ More common than optic
tract or LGN lesions
 Anterior/lateral bundle (Meyer loop)

6.  Contralateral upper homonymous
quadrantanopsia (pie in the sky)
 Posterior/medial bundle
 Contralateral lower homonymous quadrantanopsia
 Visual cortex_ contralateral homonymous
hemianopsia with macular sparing

In terminal glaucoma
only a small temporal island of vision or small central
island may remain.
Central vision may be good when all peripheral vision
may be lost.