Optic Nerve Pathologies.. An introduction

2. DISEASES OF THE OPTIC
NERVE
BY: SUMAYYA NASEEM
INTERNEE OPTOMETRIST

3. Optic nerve
The optic nerve (also known as cranial nerve II) is
a continuation of the axons of the ganglion cells in
the retina.
There are approximately 1.1 million nerve cells in
each optic nerve.
The optic nerve, which acts like a cable connecting
the eye with the brain, actually is more like brain
tissue than it is nerve tissue.

6. Optic Neuritis
• “Optic neuritis” is an inflammation of the optic
nerve.
• It may affect the part of the nerve and disc within
the eyeball (papillitis) or the portion behind the
eyeball (retrobulbar optic neuritis) .

7. Causes
• Malnutrition. E.g. vit B complex deficiency.
• Infections such as viruses (especially in children), measles, meningitis, syphilis,
sinusitis, tuberculosis, and human immunodeficiency virus (HIV)
• Tumors
• Chemicals or drugs such as tobacco, lead, methyl alcohol, ethambutol,
chloroquinine, arsenic, and certain antibiotics
• Certain autoimmune diseases such as multiple sclerosis
• Intraocular inflammation (uveitis)
• Rare causes include diabetes, hypertension, anemia, Grave's disease, bee stings,
vaccinations, and injuries. However, the cause of optic neuritis is often
unknown.

8. 1. Papillitis
• It is the inflammation of intraocular part of
optic nerve ( optic disc).
Symptoms
• Loss of vision
• Complete or partial blindness
• Loss of some or all color vision (red green)
• Pain behind the eye.
• Painful eye movements

9. Blurred vision

11. Signs
 Disc = hyperemic
 Margins = blurred.
 Oedematous

12. P
A
P
I
L
L
I
T
I
S

13. 2. Retrobulbar neuritis
• It the inflammation of the posterior part of
the optic nerve, behind the globe.
• There is a common saying:
‘PATIENT SEES NOTHING & THE DOCTOR
SEES NOTHING’

14. Signs & Symptoms
• Loss of vision
• Pain behind the eye.
• RAPD
• Complete recovery may take place, but
usually optic atrophy.

15. Investigations:
• Ophthlamoscopy
• Pupillary reflex
• Visual field
• Color vision
• CT Scan Brain
• MRI Brain
Treatment:
• Many cases improve without
treatment
• Systemic I/V steroids—3 days.

16. Fundus photographs and visual fields of patient with ON.
(a) Fundus photographs showing mild swelling of both optic discs (left, right eye;
right, left eye).
(b) Visual fields showing bilateral central scotoma and blind spot enlargement
(left, left eye; right, right eye).

17. Papilloedema
• It is defined as swelling of the optic disc.
Causes:
• Increased ICP
• Trauma / head injury
• Tumor (brain, orbital)
• Sub dural or sub arachnoid hemorrhage
• Meningitis
• Encephalitis

18. Signs & Symptoms
• Headache
• Nausea & vomiting
• Mild decrease in vision
• Paralysis of extra ocular muscles.
Observer will see:
• APD or RAPD
• Optic disc swelling
• Hyperemia
• Blurred margins
• Loss of venous pulsations
• Hemorrhages on the disc margin.

20. Investigations:
• Ophthlamoscopy
• Pupillary reflex
• CT Brain
• Visual Fields
Treatment:
• Directed towards the cause.

21. Glaucoma
• It is a syndrome in which there is :
1. IOP is raised.
2. Cupping of optic disc.
3. Visual field constriction.

22. Signs & symptoms
• Decrease in vision
• V.F. defect
• Headache
• Nausea & vomiting
• Haloes
Observer will see:
• Raised IOP
• RAPD
• Optic disc cupping
• Hemorrhages on the disc margin.
• V.F. defect
• Optic atrophy (last stage)

24. CDR (cup disc ratio)

25. Arcuate Scotoma

26. Progressive cupping of the optic disc. Early progression of cupping can be seen by
comparing photographs of the optic nerve. The optic cup which was initially not visible
(A) has enlarged over time (B).

27. Optic nerve hemorrhage. There is a flame-shaped hemorrhage
of the optic nerve located at the arrow at 5 o’clock

28. Humphery visual field analyzer

31. Observed clinically as pallor of the disc:
•PRIMARY - disc pale & white, margins are distinct
•SECONDARY - disc pale & white, margins indistinct
- such cases result from previous oedema or
inflammation of the nerve head.
Optic atrophy

32. Causes:
• Same as optic neuritis.
Signs & symptoms:
• Loss of vision
• Loss of brightness & color discrimination
• Diminished or absent Pupillary reflex
• V. F. defect
• Blindness ( end result)
Treatment:
• Optic nerve can’t regenerate, so visual loss is
irreversible.

33. Optic atrophy

35. Tumors
• Intrinsic - e.g. gliomas, melanocytomas and
meningiomas originating from nerve tissue.
• Extrinsic e.g. meningiomas of sphenoidal ridge or
olfactory groove, pituitary adenomas and some
metastatic tumors.

36. Optic nerve glioma
• Optic nerve glioma (also known as optic pathway glioma) is the
most common primary neoplasm of the optic nerve.
Signs & symptoms:
• Problem in ocular motility
• Proptosis
• Defective vision if they affect the ON conductive system
• Nystagmus
Diagnosis:
• CT
• MRI

37. a) Axial orbit CT scan shows enhancing glioma involving the left intraorbital optic nerve (b) Fundus
photograph Image shows marked swelling of the left optic disc. (c) Patient was treated with an excision of the
orbital optic glioma of the left eye. Photograph shows the excised specimen. (d) Fundus photograph 3
months after the optic nerve excision. Image shows optic disc pallor and tractional retinal detachment.

38. Proptosis due to Glioma

39. Congenital defects
• Optic nerve hypoplasia (small+ poorly developed disc)
• Optic nerve pit (small deep hole in centers of optic disc)
• Optic disc coloboma

40. Optic nerve hypoplasia

41. Optic nerve pit

42. Colobomas
• Incomplete closure of fetal cleft thus appearing inferiorly. May
be associated with choroidal /iris coloboma.
• Optic nerve coloboma (medical condition): A hole in the eye
structure called the optic nerve which is responsible for sending
visual information from the eye to the brain. Severity of
symptoms is determined by the size of the defect.
• Impaired vision
• V.F. defect
• Field defect corresponds to the area of projection of the missing
fibers.

43. Optic nerve coloboma