So What’s the problem?

The problem is:

• There is a misdiagnosis in 25% of cases of optic nerve disease on presentation with young people being assumed to have Optic Neuritis and older people AION

• There is no treatment for these conditions – observation only. So there will be a delay in initiating appropriate treatment if the neuropathy is due to something else

Why does this happen?

Because we take a short history, have a look then fit

what we have heard and seen (with necessary perceptual modification) to one of our

stock diagnoses.

Three common Optic Neuropathies

1. Glaucoma2. Optic neuritis

3. Ischaemic optic neuropathy

Glaucoma

• Typical History:

– None. Patients rarely present because of symptoms of glaucoma

Glaucoma

• Typical Examination:– Visual acuity is normal– Colour testing is normal– External examination is normal ie no proptosis,

ptosis etc– Pupils are normal– Disc changes are “glaucomatous” ie increased cd

ratio, not ISNT, notch, haem loss of nerve fibre layer, and areas of preserved rim are not pale

Glaucoma• Typical Perimetry

– Field loss crosses vertical midline and stops at horizontal midline

– Defect matches disc changes

Ok So this is glaucoma

This probably is

This too even though IOP is low

• A 72 year old incidentally noted to have a field defect on routine testing by his optometrist

• VA R&L 6/6• Colour vision normal• IOP 14mmHg R&L• R disc cupped• Glaucomatous field

defect

LTG because

• Asymptomatic• Colour vision normal• Characteristic disc changes without pallor of

remaining nerve tissue• Field defect matched disc changes

But this isn’t

• 63 year old investment banker presents having noticed slow reduction in right vision

• VA 6/6 OU• IOP R 29mmHg L 27mmHg• Ishihara down on right• Diffuse cupping of right

disc. Cd ratio 0.6 Pale rim• Left disc looks normal CD

ratio 0.4

Not glaucoma because:

• Patient complained of progressive loss of vision• Colour vision down• Optic disc pallor• Field did not match disc

• NB Diagnosed as glaucoma. After 2 years of progressive vision loss a pituitary tumour was found

Optic Neuritis

• Typical History:– Age: 15 to 45 male or female– Otherwise well– Unilateral– Acute onset worsening over hours to days– Pain..worse on eye movement– No diplopia or other neurological signs

Optic Neuritis

• Typical Examination– No proptosis, ptosis, eye movements normal– VA and colour vision down unilaterally– RAPD– Disc normal or mildly swollen…no disc pallor– No signs of vasculitis or intraocular inflammation– Other eye normal

Optic Neuritis

• Typical Perimetry– Anything goes in either eye

• Symptoms stop getting worse within 2 weeks and start to improve within 4 weeks

For example

• A 29 year old computer programmer presents with progressive loss of right vision in her left eye. Started 4 days ago and has stabilised.

• Pain on eye movement• VA R 6/6 L 6/18• RAPD• Colour vision down on left• Right disc normal Left disc

swollen

Probably optic neuritis because

• History– Age 15 to 45– Otherwise well– Unilateral symptoms– Rapid onset of symptoms– Eye or orbital pain– No other neurological symptoms

• Examination– No orbital signs– RAPD– Disc normal or mildly swollen– No disc pallor– No signs of intraocular inflammation or vasculitis– Other eye normal

This isn’t

• A 22yr old medical student presents with a 6 day history of painless subacute loss of vision in her left eye.

• VA R 6/5 L 6/18• Ishihara R 13/13 L 6/13• Left RAPD• Discs look normal

Advised that things should get better and routine appointment made with a neurologist (for a few

months later)

6 weeks later represented with worse vision and a swollen disc.

MRI showed a diffuse mass infiltrating the optic nerve which turned out to be a

lymphoma

Not typical Optic neuritis because of:

• absence of pain• slow onset of symptoms• progression of symptoms beyond 2 weeks

Ischaemic optic neuropathy

• Typical History– Age 40 or over male or female– Vascular risk factors present OR symptoms of giant

cell arteritis– One eye affected – Acute onset and no improvement over time– No pain– No diplopia

Ischaemic optic neuropathy

• Typical Examination– Markedly reduced VA and colour saturation– No orbital or neurological signs (proptosis, ptosis,

abnormal eye movements)– RAPD– Mild to severe disc swelling: hyperaemic or pale

swelling, sectorial or diffuse

For example

• A 52 year old truck driver presents with sudden painless loss of right vision while driving. No change since onset of symptoms

• VA R 6/36 L 6/6• RAPD• Disc swollen• Left disc small, crowded• No meds but smokes

Clinically AION Because:

• History– Over 40– Vascular risk factor present– Unilateral– Very sudden onset– Painless

• Examination– No orbital signs– RAPD– Diminished colour vision– No other intraocular disease– Swollen disc– Other eye “Disc at RisK” but otherwise normal

But not this time!• 46 year old accountant

presents with progressive loss of right vision over 2 weeks

• VA R 6/18 L 6/6• RAPD• Colour vision down on the

right• Disc is moderately swollen• History of hypertension,

hypercholesterolaemia and a family history of heart disease

Not AION Because:

• Onset slow

• On further questioning there was an 8 week history of night sweats and lethargy and on further examination cervical lymphadenopathy and a history of a cat scratch

QUIZ TIME

Quiz 1

• A 20 year old newlywed is referred by ENT colleague to have her pressures checked because of headaches (having found no sinus disease).

• Overweight but otherwise well with no visual symptoms.

Visual acuity 6/6 OUPupils normal

IOP 16mmHg OUColour vision: some errors on Ishihara

Discs: Pharque! Look at that!

What is the diagnosis?

1. Optic neuritis2. Ischaemic optic neuropathy

3. Acute domestic bliss4. Other

Answer

• D. Other

Quiz 2

A 75 yr old man presents with acute loss of vision in one eye.

Usually well but off colour lately and not eating.

Bad headache for two weeks. Had a fall a few months ago and sustained

fractured orbit

Visual acuity Right eye PL. Left eye 6/6. IOP 16mmHg OU. Right APD.

Other signs

What is diagnosis?

1. Ischaemic optic neuropathy2. Traumatic optic neuropathy

3. Optic neuritis4. Pituitary tumour

Answer

• 1. ION

Quiz 3

A 70 yr old lady presents for glasses check.Incidentally found to have IOP of 48

mmHg right and 28 mmHg left.VA 6/12 OU

Pupils reacting normallyColour vision normal

Ant seg photo Right eye

Discs

Fields

What is the diagnosis?

1. CVA2. Ischaemic optic neuropathy.

3. Open angle glaucoma.4. Closed angle glaucoma

Answer

• 3 or 4