This document discusses the visual pathway and visual field testing. It defines the visual pathway, which includes the retina, optic nerve, optic chiasm, optic tract, lateral geniculate nucleus, optic radiation, and visual cortex. It defines the visual field as the area in which objects are visible at a given moment and discusses techniques to measure the visual field, including kinetic perimetry like Goldmann perimetry and static perimetry like Humphrey perimetry. Different visual field types and defects are also mentioned.

1. Visual Field
Aseel Al Rashdi
R1
Neurophthalmolgy course
2019

2. Outline
• Visual pathway.
• The definition and concept of visual field.
• Types of Visual field.

4. Visual pathway : Retina
Superior and inferior nasal
Straight course
Temporal axons arching course
Papillomacular bundle (PM) Straight
Fibers never cross the horizontal midline !

5. Visual pathway : Chiasm

7. Visual pathway : Optic Tract
• Carry Fibers of 1 Hemi -feild .
• Lower retinal Fibers and their projection
lie in the Lateral portion of the optic
tract .
• Superior retinal fibers and their
projections lie in the Medial portion of
the optic tract .

8. Visual pathway : Lateral geniculate Nucleus

9. Visual pathway :Optic Radiation

10. Visual pathway : Visual cortex
• central visual field is
located in the
posterior portion of
the calcarine sulcus .
• peripheral visual field
in the anterior
portion.

11. Central And Peripheral VF Zones

12.  VA
 Amsler
gird
 Confrontation
field test

13. Definitions
• Visual Acuity ( greatest resolution of vision ) the capacity to
discriminate the fine details of objects when centrally fixating.
• Visual Field ( visual sensitivity to light or motion in different locations)
the portion of space in which objects are visible at the same moment
during steady fixation of gaze in one direction.

14. Extension of VF :
Temporal : 90 degrees
Inferior : 70 degrees
Superior : 60 degrees
Nasal : 50 degrees
RE

15. How to measure the VF function ? (Quantify)
• Perimetry :
• Static or dynamic.
• Automated or manual.
• Stimulus modifying parameters :
• Luminance
• Size ( smaller , more sensetive)
• Color
Light intensity Unit : Apostilb (ASP) usually
background of test kept at 31.5 ASP
Unit of attenuation of light sensitivity =
Decibels (dB)
1dB = 1/10 log of unit.

16. Which one is more sensitive to light ?
30 dB 28 dB 26 dB 17 dB
Increase in Decibels = Decrease light intensity = light sensitivity at that retinal point is high if patient can detect the light
Dimmer light
Greater visual
sensitivity

17. Traquair’s difinition of VF : Island of vision in
sea of blindness

18. Kinetic Perimetry
• Example : Goldmann Perimetry
• Method(Manual):
• Target is moving.
• Different sets of stimulus .
I2 , I4, II4, IV4, and V4.

19. Radial
meridians

20. The line that joins points having
the same threshold is called an
Isopter.
Forming an eccentric circles

21. Normal Goldmann VF test

22. Nasal Hemi-field loss

23. Kinetic Perimetry
• Advantages :
1. Can evaluate the entire visual
field
2. Helpful in detecting specific
field defect eg . Ring scotoma
in Retinitis pigmentosa .
• Disadvantages :
1. Depends on skills of
perimetrist
2. Variable reproducibility

24. Traquair’s difinition of VF : Island of vision in
sea of blindness

25. Static Perimetry
• Example : Humphry VF test
• Automated perimetry : Standard
• Static : targets does not move
• Same size stimulus.
• Change stimulus intensity at different points . ( dB )

27. • White target on white
background ( Achromatic)
• Light presented for <0.5 sec
• Determines the the intensity of
the light that is seen 50% of the
time . ( Threshold )

28. 4-2-1 dB Stair Casing Strategy

30. Static Perimetry
• Advantages :
1. Standardized
2. Comparison with database
• Disadvantages :
1. Patient factors : attentiveness ,
response errors .
2. Duration of test