For Students

1. Lesions of the visual path wayLesions of the visual path way
Presented byPresented by
Asit PramanikAsit Pramanik
B.OptmB.Optm

2. Lesions of the Optic NerveLesions of the Optic Nerve
This are characterised byThis are characterised by
marked loss of vision ormarked loss of vision or
complete blindness on thecomplete blindness on the
affected sides with abolition ofaffected sides with abolition of
the direct light reflex on thethe direct light reflex on the
ipsilateral side and consensualipsilateral side and consensual
on the contralateral side. Nearon the contralateral side. Near
reflex is present.reflex is present.
 optic atrophy, traumaticoptic atrophy, traumatic
avulsion of the optic nerve, opticavulsion of the optic nerve, optic
neuropathy and acute opticneuropathy and acute optic
neuritis.neuritis.

3. Lesions through proximal part ofLesions through proximal part of
the optic nervethe optic nerve
Ipsilateral blindness,Ipsilateral blindness,
contralateral hemianopiacontralateral hemianopia
and abolitions of directand abolitions of direct
light reflex on the affectedlight reflex on the affected
side and consensual of theside and consensual of the
contralateral sidecontralateral side

4. Central lesions of the chaismaCentral lesions of the chaisma
These are characterised byThese are characterised by
temporal hemianopiatemporal hemianopia
 supra sellar aneurysms,supra sellar aneurysms,
tumours of the pituitarytumours of the pituitary
gland, craniopharyngioma,gland, craniopharyngioma,
supra sellar meningioma andsupra sellar meningioma and
glioma of the third ventricleglioma of the third ventricle

5. Lateral chaisma lesionsLateral chaisma lesions
these are characterised bythese are characterised by
binasal hemianopiabinasal hemianopia
 distension of third ventricledistension of third ventricle
causing pressure on the eachcausing pressure on the each
side of the chaisma andside of the chaisma and
atheroma of the carotid oratheroma of the carotid or
posterior communicatingposterior communicating
arteries.arteries.

6. Lesions in the optic tractLesions in the optic tract
This are characterised byThis are characterised by
incongruous homonymousincongruous homonymous
hemianopiahemianopia
 syphilitic meningitis orsyphilitic meningitis or
gumma, tuberculosis, tumoursgumma, tuberculosis, tumours
of the optic thalamus, andof the optic thalamus, and
aneurysm of the superioraneurysm of the superior
cerebellar and posteriorcerebellar and posterior
cerebral arteries.cerebral arteries.

7. Lesions of lateral geniculateLesions of lateral geniculate
bodiesbodies
This produce homonymousThis produce homonymous
hemianopia with sparing ofhemianopia with sparing of
pupillary reflex and maypupillary reflex and may
end in partial optic atrophyend in partial optic atrophy

8. Lesions of optic radiationLesions of optic radiation
Involvement of total opticInvolvement of total optic
radiations produce completeradiations produce complete
homonymous hemianopia.homonymous hemianopia.
Inferior quadrantic (pie on theInferior quadrantic (pie on the
floor) hemianopia occurs in thefloor) hemianopia occurs in the
lesions of parietal lobelesions of parietal lobe
(containing superior fibres of(containing superior fibres of
optic radiations). Superioroptic radiations). Superior
quadrantic hemianopia (pie in thequadrantic hemianopia (pie in the
sky) occurs in the lesions ofsky) occurs in the lesions of
temporal lobe (containing inferiortemporal lobe (containing inferior
fibres of optic radiations)fibres of optic radiations)
 vascular occlusions, primaryvascular occlusions, primary
and secondary tumours andand secondary tumours and
trauma.trauma.

9. Lesions of the visual cortexLesions of the visual cortex
Congruous homonymousCongruous homonymous
hemianopia usually sparing inhemianopia usually sparing in
the macula is a features ofthe macula is a features of
occlusion of posterior cerebralocclusion of posterior cerebral
arteries supplying the anteriorarteries supplying the anterior
part of the occipital cortex .part of the occipital cortex .
Congruous homonymousCongruous homonymous
macular defect occurs in themacular defect occurs in the
lesions in the tip of thelesions in the tip of the
occipital cortex following headoccipital cortex following head
injury or gun shot injuries.injury or gun shot injuries.

10. Thank YouThank You