This document discusses visual field defects and their causes. It provides details on the normal extent of the visual field and terms used to describe defects. Common causes of central and peripheral visual field loss are listed. Specific defects like scotomas, hemianopias, and quadrantanopias are defined. Various visual field tests are described, including confrontation testing, automated perimetry, and Amsler grid testing. The Amsler grid is used to evaluate the central 20 degrees of vision and screen for macular problems.

1. Visual field
defects
PRESENTED BY:
MD JARGIS ALAM
(20ISMO16)
From: 2nd year Optometry
SMD, UOH

2. The normal extent of field of vision
• The Normal visual field is defined as "Island of vision
surrounded by a sea of blindness"
❖60°nasally.
❖50°superiorly
❖70°inferiorly.
❖90° temporally

3. Terms
Visual field defect - a portion of visual field missing. This may be:
1. central (e.g. optic disc or nerve problem)
2. peripheral (along the visual pathways from the optic chiasm
back).

4. Common causes of VF defect
❏ Central field loss occurs with:
1.Optic neuropathy 2.Macular
degeneration
3.Macular hole 4.Cone dystrophies
● A number of rare conditions like Best's disease, Stargardt's disease and
achromatopsia.

5. Common causes of VF defect
❏ Peripheral field loss occurs with:
1.Retinitis pigmentosa 2.Chorioretinitis
3.Glaucoma 4.Retinal detachment
5.Leber's optic atrophy

6. Visual field defects
● Scotoma - this is a type of visual field defect. It is a defect
surrounded by normal visual field.
➢ Relative scotoma- an area where objects of low luminance
cannot be seen but larger or brighter ones can.
➢ Absolute scotoma- nothing can be seen at all within that area.

8. Hemianopia
binocular visual defect in each eye's hemifield.
➢ Bitemporal hemianopia - the two halves lost are on the outside of each eye's
peripheral vision, effectively creating a central visual tunnel.
➢ Homonymous hemianopia - the two halves lost are on the corresponding area
of visual field in both eyes, i.e. either the left or the right half of the visual field.

9. Cont.
Altitudinal hemianopia - refers to the dividing line between loss and sight being
horizontal rather than vertical, with visual loss either above or below the line.
Quadrantanopia - is an incomplete hemianopia referring to a quarter of the
schematic 'pie' of visual field loss.
Sectoral defect- is also an incomplete hemianopia

10. Homonymous hemianopia Bitemporal hemianopia

11. Altitudinal hemianopia
Quadrantanopia Sectoral defect

12. Visual Field Examinations
Six types of visual field tests
1.Confrontation visual field test.
2. Automated static perimetry test.
3.Kinetic visual field test.
4.Frequency doubling perimetry.
5.Electroretinography.
6.Amsler grid

13. AMSLER GRID CHART
● Important in testing macular function when v/a decreased or
distorted
● Chart consisting of white lines on black background & central
white dot for fixation
● 10 cm square divided in 5mm square
● It is use to evaluate 20 degree of v/f surrounding fixation.
● This test is use for screening & diagnostic purpose

15. Procedure
❖ Test is done uniocularly
❖ Patients pupil should not be dilated
❖ Patient should were their full refractive correction
❖ Use good illumination on chart
❖ Hold the chart at 30cm from patients eye.
❖ Ask the patient to fixate on central white dot & tell patient while looking on
central dot give the answers of following questions-

16. Questionaries
1.Can you see the central white dot in the center of grid?
2.While looking at central dot ,can you see all four quadrants of
chart simultaneously?
3.Does the grid appears to have any missing or distorted area?
4.Are there any area of grid that have an unusual appearance?
5.Are any square blurring/missing?

17. Replies
•If the answer is ‘Yes’, a central scotoma is unlikely
unless the clinician is obtaining a false-positive
response due to poor patient compliance.
•If the answer is ‘ It looks washed out’ or ‘It seems
slightly blurry’, one should suspect for a relative
central scotoma.