visual field- its assessment, defects, diseases associated. Types of visual field defects. visual field defects in glaucoma in detail. Humphrey's visual field analyser chart.

1. VISUAL FIELD DEFECTS

2. INTRODUCTION
• Visual field : 3D area of a subject’s
surroundings that can be seen at a time
around a point of fixation.
• Traquair: “Island of vision surrounded by a
sea of darkness”

3. The normal extent of vision
60°superiorly .
 60°nasally .
 75°inferiorly .
 100° temporally .

4. • VF divided into central and peripheral field
 Central field- area from fixation to a circle 300
- physiologic blind spot on
temporal side
 Peripheral field- rest of area

5. • Scotoma: Area of depressed or lost vision
surrounded by area of normal vision.
- Positive & negative
- Absolute & Relative

6. COMMON CAUSES OF VISUAL FIELD
DEFECT
• Central field loss
 Optic neuropathy
Macular degeneration
Macular hole
Cone dystrophies

7. • Peripheral field loss
Glaucoma
Retinal detachment
Retinitis pigmentosa
 Chorioretinitis

8. Visual Field Assessment
• Screening test
 Confrontation method
• Quantitative methods
 Perimetry

9. Advantages
• Localize the site of the lesion by mapping the
visual field deficit by finger confrontation
• Quantitative visual field
the perimeters provide a sensitive means of
detecting scotomas in the visual field.
• They are exceedingly useful for serial
assessment of visual function in chronic
diseases such as glaucoma

10. INTERPRETATIONS
• Scotoma in one eye- lesion in either
Optic nerve Retina

11. Retinal diseases
• When photoreceptors affected
 Corresponding scotoma
 more loss of VF for blue than red
• When ganglion cell layer/nerve fibre layer
affected
 Does not correspond to lesion
 More loss of VF for red than blue

12. •Temporal bundle lesion
 Nasal defect
 Arcuate in shape
• Nasal bundle lesion
 Temporal defect
 Fan shaped

13. • Damage to macula
Central scotoma

14. Optic nerve lesion
• Central or centrocecal scotoma
• Field defects more marked to red
• VF normal in early papilloedema
• Enlargement of blind spot in late
papilloedema
• Altitudinal scotoma- ishaemic optic
neuropathy

15. Glaucoma
• Damage to nerve fibres in optic disc
• Arcuate fibres most prone to damage
• Macular fibres most resistant

16. Glaucomatous field defects
• Isopter contraction
• Baring of blind spot
• Small wing-shaped paracentral scotoma
• Siedel’s scotoma
• Arcuate or bjerum’s scotoma
• Ring or double arcuate scotoma
• Roenne’s central nasal step

18. Key points
• Paracentral scotoma
• Roenne nasal step
• Paracentral scotoma widens, new scotoma
forms, they coalasce arching shape
between the nasal horizontal meridian and
the blind spot
• Affect both upper &lower regions Ring-
scotoma

19. Advanced glaucomatous field defects
• Tubular vision
• Temporal island of vision

20. • Defect identical in other neuropathies-
differentiated by history & examination
- VF defects before loss of vision
- Colour blindness typically blue-yellow
- Ophthalmoscopic appearance of disc
- Tonometry