Visual pathway of eye with necessary lessions

this ppt contains a complete notes of visual pathway .

1. Visual pathway & optic nerve

2. Retina Optic nerve Optic chiasm Optic tract Lateral geniculate body Optic radiation Visual cortex Visual pathway consists of:

3. Retina

4. Optic nerve Second cranial nerve Extends from optic disc to optic chiasma It is backward continuation of nerve fibre layer of retina Contains afferent(sensory) fibres of light reflex Not covered by neurilemma ( doesn’t regenerate when cut) Surrounded by meningeal sheath

5. NERVES

6. INTRAOCULAR PART This is the portion of the optic nerve that lies within the eye socket (orbit). It starts from the optic disc and extends to the point where the optic nerve penetrates the back of the eye (sclera) and enters the optic canal. Passes through sclera, choroid and finally appears as optic disc Optic nerve head has avg. diameter 1.5mm Divided: Surface nerve fibre layer Pre- laminar region Lamina cribrosa Retrolaminar region

7. INTRAORBITAL PART

8. INTRACANALICULAR PART

9. INTRACRANIAL PART

10. OPTIC CHIASMA

11. OPTIC TRACT

12. LATERAL GENICULATE BODY

13. OPTIC RADIATION Extend from LGB to visual cortex Fibres of optic radiation spreads out fanwise to form medullary optic lamina

14. VISUAL CORTEX The final destination for visual information is the visual cortex, located in the occipital lobe at the back of the brain Here, the information is further processed and interpreted, allowing us to perceive shapes, colors, movement, and depth. It is divided into primary visual cortex(conscious) and secondary visual cortex by calcarine fissure

15. Fibers affected Field affected Right temporal fibres + Right nasal fibres Right nasal visual field + Right temporal visual field LESSION 1 OPTIC NERVE(RIGHT) LEFT VF RIGHT VF

16. FIBERS AFFECTED FIELD AFFECTED Left nasal fibres + Right nasal fibres Left temporal visual field + Right temporal visual field LESSION 2 OPTIC CHIASMA RIGHT VF LEFT VF

17. FIBRES AFFECTED FIELD AFFECTED Left temporal fibres + Right temporal fibers Left nasal visual field + Right nasal field LESSION 3 Lateral optic chiasm LEFT VF RIGHT VF 3 3

18. FIBRES AFFECTED FIELD AFFECTED Left temporal + Right nasal Left nasal + Right temporal field LESSION 4 OPTIC TRACT(LEFT) LEFT VF RIGHT VF 4

19. LESSION 5 OPTIC RADIATION (LEFT) FIBRES AFFECTED FIELD AFFECTED Left temporal + Right nasal Left nasal + Right temporal LEFT VF RIGHT VF 5

20. LESSION 6 ANTERIOR VISUAL CORTEX LEFT VF RIGHT VF 6

21. THANK YOU