OPTIC NERVE

Question 1

1. What are the two types of optic disc edema?
2. What are causes of pseudo disc edema?
3. What is papilledema? And its Causes.
4. SS of papilledema?
5. Treatment of papilledema?
6. What is foster Kennedy syndrome?

Answer 1

1. Active ….due to inflammation of optic nerve head papillitis.
   Passive ….non inflammatory edema due to change in perfusion pressure at level of lamina cribrosa.
2. High hypermetropia
   Optic disc Drusen
   Persistent hyaloid tissue.
3. It is edema of optic nerve head secondary to raised intracranial pressure. Always bilateral

Raised ICP. ➡️ stasis of axoplasm. ➡️ Optic disc swelling .

Causes include
Space occupying lesions
Pseudo tumor cerebri
Impaired CSF circulation
Intracranial infection
Head injury
Hypervitaminosis

4. Headache,nausea, vomiting and altered consciousness.

Disc hyperemia and edema with retaining of central cup
Absent venous pulsations
Engorged blood vessels
Blurred disc margins
Hemorrhages
Hard Exudates
Incomplete macular star temporal part missing
Enlarged blind spot
Patons lines retinal folds
In late stages optic atrophy occurs
Visual acuity, pupillary reactions, colour vision remain Normal.

5. Treat the underlying cause
   Give diuretics and do repeated lumber punctures to lower ICP.
6. Frontal lobe tumor causes optic atrophy on the side of lesion and papilledema on the other side.

Question 2

1. What is optic neuritis?
2. What are SS of optic neuritis?
3. Types of optic neuritis?
4. Treatment of optic neuritis?

Answer 2

1. Inflammation of optic nerve.
2. Visual acuity and color vision is reduced.
   RAPD is present.
   Disc edema with blurred central cup is present.
   Pain with ocular movements.
   Phosphenes sensations of coloured flashes or sparkles on orbital compression.
   In neuroretinitis, macular star is also present.
   There is central or centrocecal scotoma.
   VEP are also abnormal.
3. Papillitis… inflammation of optic nerve head.
   Neuroretinitis… papillitis ass with retinal involvement.
   Retrobulbar optic neuritis… inflammation of orbital part of optic nerve in which optic disc appears normal.

4.IV methylprednisolone
IM interferon beta
Vitamin B12,B6,B1 injections.

Question 3

1.What is Optic neuropathy?

2. Classify optic neuropathy!

Answer 3

1. Inflammatory disease of optic nerve fibre or ganglion cells resulting in visual loss.
2. Glaucomatous optic neuropathy

Anterior ischemic optic neuropathy
(Arteritic and non arteritic)

Compressive optic neuropathy

Infiltrative optic neuropathy

Traumatic optic neuropathy

Mitochondrial optic neuropathy

Nutritional optic neuropathy

Toxic optic neuropathy (methanol and ethambutol)

Question 4

1. Difference bw arteritic and non arteritic optic neuropathy!
2. What are features of Lebers Hereditary optic neuropathy?

Answer 4

1. Arteritic is caused by giant cell arteritis. ➡️Vasculitis of short ciliary artery➡️ ischemic necrosis of optic nerve head
   Occurs 10%
   Swollen disc,RAPD is present.
   Altitudinal visual field defects

Treatment… systemic steroids

Non arteritic 90%
Caused by HTN,DM, hyperlipidemia.
RAPD present. Swollen disc and pale
.Altitudinal visual field defects present.

Treatment…treat the underlying cause.

2.disc hyperemia
Peripapillary telengiectasia
Peripapillary nerve swelling

Question 5

1.Types of optic atrophy!

Optic atrophy is degeneration of retinal ganglion cells and their axons.

2.features of optic atrophy?

Answer 5

Primary
Lesion is proximal to optic disc so it is without swelling of optic nerve head.
Optic disc is chalky white.
Absent vessel sheathing

Secondary
Preceded by swelling of optic disc with proliferation of glial tissue as in papillitis,chronic papilledema,AION.
Disc is grey or dirty white.
Sheathing of vessels is present.

Consecutive
Ass with retinal disease e.g retinitis pigmentosa,high myopia ,CRVO
waxy disc

Glaucomatous

2.visual acuity is reduced
Colour vision is altered
RAPD present
Visual field defects present