1. The visual pathway includes the optic nerve, optic chiasm, optic tracts, lateral geniculate bodies, and optic radiations which transmit visual information from the eyes to the visual cortex. 2. Lesions along the visual pathway can cause different types of visual field defects including hemianopia, quadrantanopia, and homonymous hemianopia. The type and characteristics of the field defect depend on the specific location of the lesion. 3. Pupillary reflexes involve both afferent and efferent pathways. Abnormalities of the pupillary reflexes can localize lesions and help diagnose conditions affecting the visual pathway or autonomic nervous system.

1. Visual & Pupillary Pathway
and it’s lesions

2. VISUAL PATHWAY ANATOMY

3. COMPONENTS OF VISUAL PATHWAY

4. VISUAL
PATHWAY

5. Anopia

6. •Hemianopia: Loss of vision in one half of
visual field
Heteronymous hemianopia

7. Quadrantanopia
Loss of vision in a quadrant of visual field
Homonymous type

8. Homonynous hemianopia
Congruous Incongruous
Defects are
identical in
size,shape,
location, slope
of margins
eg-Post optic
radiation lesions
Defects are
dissimilar
eg-Optic tract &
LGB lesions

9. inverted
reversed

10. LESIONS
OF
VISUAL
PATHWAY

11. Field Defects in Lesions of Optic Nerve
Anopia Cause:
traumatic avulsion or optic atrophy
Clinical features:
Ipsilateral anopia
(loss of vision)
Loss of direct pupillary reaction
(same side)
loss of consensual pupillary reaction
(other side)
Near or accommodation reflex is
present
Anterior chiasmal syndrome

12. Field Defects in Lesions of Optic Chiasma
(Less common)
 IIIrd ventricle
enlargement /
dilatation
 Atheroma of carotids or
posterior
communicating arteries
 Pituitary adenoma
or malignancy
 Craniopharyngioma
 Chronic chiasmal
arachnoiditis
 Fracture of the base
of skull
Middle chiasmal syndrome

13. Pituitary Adenoma
B/L superotemporal
quadrantanopia

14. Craniopharyngioma
B/L inferotempoal quadrantopia

15. Field Defects in Lesions of Optic Tract
left optic tract lesion
involving left cerebral
peduncle and left 3rd nerve.

16. Causes of optic tract lesion

17. Field Defects in Lesions of
Lateral geniculate Body (LGB)
sparing of pupillary
reflexes

18. Lesion of optic radiations
Anterior temporal lobe Parietal lobe
Pie in the sky
Pie on the floor
Posterior part of
Internal capsule (Ant
occipital cortex)
c/o visual
hallucination(for
med)
c/o uncinate fits
c/o acalculia
c/o agraphia
c/o agnosia
c/o spatial neglect
c/o constitutional
apraxia

19. Common causes of lesions of optic
radiations

20. Lesions of optic radiations-Clinical
presentation

21. Field Defects in Lesions of Visual Cortex
B/L homonymous
hemianopia with
macular sparing
Congruous homonymous
macular defects

22. Common causes of lesions of Visual
Cortex

23. Clinical presentation in Visual Cortex
Lesions (Cortical blindness)
[Anton syndrome]
[Riddoch phenomenon]
[Alexia]

24. Differences between occipital lobe and
optic tract lesions
Clinical Features Occipital lobe
lesion
Optic tract lesion
Pupillary reaction Normal Abnormal
Field defect Congruous Incongruous
Macular involvement Sparing Involved
Optic atrophy
- +

26. LIGHT REFLEX – Afferent pathway
From rods and cones to ganglion
cells, information reaches optic
nerve and travels to optic chiasma
Nasal fibres decussate and travel
along opposite tract to terminate
in contra lateral pretectal nucleus
Fibres from temporal retina pass
uncrossed to terminate in the
ipsilateral pretectal nucleus

27. LIGHT REFLEX – Internuncial
pathway
Internuncial fibres connect each
pretectal nucleus with Edinger
Westphal nucleus of both sides in
the midbrain
This forms the basis of the
CONSENSUAL LIGHT REFLEX

28. LIGHT REFLEX – Efferent pathway
Pre ganglionic fibres from Edinger
Westphal nucleus enter the
inferior division of 3rd nerve
Reach the ciliary ganglion via the
nerve to IO muscle
Post ganglionic fibres travel along
short ciliary nerve to innervate
sphincter pupillae

29. NEAR REFLEX

30. CONVERGENCE
REFLEX
Afferent fibres from MR travel via 3rd
nerve to mesencephalic nucleus of
5th nerve and then to convergence
center in tectal area
Internuncial fibres from convergence
centre go to Edinger Westphal nucleus
Efferent fibres go along 3rd nerve to
relay in accessory ganglion and then
reach sphincter muscle

31. ACCOMMODATION
REFLEX
Afferent fibres from retina travel to
parastriate cortex via optic nerve,
chiasma, tract and radiation
Internuncial fibres relay impulses
from para striate cortex to Edinger
Westphal nucleus of both sides
Efferent fibres travel along 3rd
nerve to relay in accessory ganglion
and then reach sphincter muscle

32. SYMPATHETIC
PATHWAY
• Central 1st neuron starts in
posterior hypothalamus, descends
and terminates in ciliospinal centre
of Budge (C8, T1, T2)
2nd preganglionic neuron passes
from ciliospinal centre to end in
superior cervical ganglion in neck
3rd postganglionic neuron enters
skull, joins ophthalmic division of 5th
nerve to reach dilator muscle via
nasociliary and long ciliary nerves

33. EXAMINATION OF REFLEXES

36. Abnormalities of pupillary reflex

37. AFFERENT PATHWAY DEFECTS
1. Total Afferent Pathway Defect
(TAPD) / Amaurotic pupil

38. AFFERENT PATHWAY DEFECTS
2. Relative Afferent Pathway Defect (RAPD) / Marcus Gunn
pupil
OPTIC NERVE DISORDERS
1. Optic neuritis
2. Ischaemic optic neuropathies
3. Advance glaucoma
4. Traumatic optic neuropathy
5. Optic nerve compression
6. Optic atrophy
RETINAL DISEASES
1. Ischaemic retinal diseases (CRVO,
CRAO, BRAO)
2. Ischaemic ocular disease
3. Retinal detachment
4. Severe macular degeneration
5. Large retinal/choroidal tm.

39. Swinging flash light test

41. AFFERENT PATHWAY DEFECTS
3. Wernicke’s hemianopic pupil
Ipsilateral direct and
contralateral consensual reflex absent
Ipsilateral direct and
contralateral consensual reflex present

42. EFFERENT PATHWAY DEFECTS

43. EFFERENT PATHWAY DEFECTS
1. Tonic pupil

44. EFFERENT PATHWAY DEFECTS
Adie’s tonic pupil

46. LIGHT NEAR DISSOCIATION
Argyll Robertson pupil

47. ANISOCORIA
DIM LIGHT BRIGHT LIGHT
RIGHT –SIDED ANISOCORIA

48. EVALUATION OF ANISOCORIA
physiological

50. SYMPATHETIC PARESIS
Horner’s syndrome

51. Horner’s syndrome
• Central
• Preganglionic
• Postganglionic
CENTRAL
• Tumours and
vascular brainstem
lesions
• Syringomyelia
• Spinal cord lesions
at C8-T2
PREGANGLIONIC
• Pancoast tumour
• Carotid and aortic
aneurysm
• Malignant cervical
LN
POSTGANGLIONIC
• Vascular headache
• Head trauma
• Cavernous sinus
lesions

52. Horner’s syndrome
• Central
• Preganglionic
• Postganglionic

53. Horner’s syndrome
• Cocaine test
• Hydroxy amphetamine test
• Adrenaline/Phenylephrine test

54. Thank
you