Optic Neuritis III

Question 1

Appearance of optic disc edema

Answer 1

• Swollen nerve fibers
• Blurred margins
• Edema of the peripapillary NFL (Paton lines)
• secondary vascular dilation and leakage
• loss of spontaneous venous pulsation
• loss of the physiologic cup

Question 2

Circulation to the optic disc

Answer 2

SPCA

CRA (surface of optic disc)

Question 3

General hemodynamics patterns

Answer 3

Mean arterial pressure of the arteries entering the eye is around 65mmHg. The pressure in the episcleral veins leaving the eye is around 15mmHg
Ocular profusion pressure (OPP)=diastolic BP-IOP. Perfusion pressure in th eye is approximately 50mmHg.
Reduction of OPP causes hypoxia

Question 4

When ocular perfusion pressure drops below the osmotic pressure

Answer 4

The caps collapse resulting in perfusion crisis

Question 5

Stasis of axoplasmic flow

Answer 5

Non vasculitis ischemia

• alteration in pressure/perfusion ratio
• occlusion of disc vessels
• occlusion of the peripapillary vessels

Vasculitis (inflammation)

Mechanical

• infiltrative: neoplastic/inflammation
• compartment syndrome
• high ICP

Question 6

Ischemic optic neuropathy

Answer 6

AION: arteritis (GCA)
NAION: nonarteritic ION
DION: diabetic

Question 7

AION

Answer 7

• NAION vs AION 10:1
• sudden unilateral painless VA loss 20/200 or worse with poor recovery
• often becomes bilateral
• 70-80 year old female > male
• not particularly assocaited with risk factors: smoking, DM, overweight, HTN, cholesterol, inactive

Question 8

AION: GCA

Answer 8

• inflammation of the elastic later of medium to large arteries
• veins are not affected
• granulomatous inflammation occurs in the vessels supplying the eye cause thrombosis, then occlusion of arteries, and ischemic infarct of optic nerve head
• regional ischemia to peripapillary tissue
• GCA at a remote location will have downstream events: jaw claudication, scalp tenderness, neck pain and trouble focusing; fever, HA, weight loss

Question 9

Anteiror ischemic signs of AION

Answer 9

Tortuous conjunctival and episcleral vessels
Low grade ischemic uveitis 
Cornea edema 
Rubeosis irides and cataract 
Hypotony

Question 10

Posterior ischemic signs of AION

Answer 10

Chorioretinal degeneration
Choroidal ischemic lesions on FA
CRAO and cilioretinal artery occlusion
CWS near cilioretinal artery

Question 11

Weak perfused disc: AION

Answer 11

Pink to pale disc
Small linear flamed shaped hemorrhages
Edema and elevation

Question 12

Severe occlusive disease: AION

Answer 12

Chalk white disc

Edema and elevation

Question 13

Severe functional deficits of the disc: AION

Answer 13

BCVA 20/200 or worse, vision does not recover

RAPD, Pulfrichs distortion, CV defects

VA defects more extensive than in NAION

Question 14

Reolsved AION disc sign

Answer 14

Pale disc often with glaucomatous excavation

Question 15

Pulfrich Effect

Answer 15

-it can be tested for in the office. Is a stereo illusion in which a to and fro motion in the plane facing the subject is seen as an elliptical movement by an individual with a unilateral optic neuropathy

Question 16

AION managment

Answer 16

• affected eye rarel recovers
• fellow eye needs protected
• ESR, CRP, CBC, serum fibrinogen, platelet counts (ESR: men age/2, women age+10/2)
• temporal artery biopsy within 1 week after stating steroids

Question 17

What confirms diagnosis of GCA

Answer 17

Temporal artery biopsy

-you may need to repeat if negative because it has skip lesions

Question 18

1 month after GCA AION

Answer 18

OCT reveals decreased macular ganglion cell layer thickness

Question 19

NAION profile

Answer 19

• whites
• males
• sudden unilateral painless vision loss
• ages 50-70 with peak 55-65 (younger than AION)

Association’s
- compartment syndrome: disc at risk-always examine the other eye and record C/D

Question 20

Pathophysiology of NAION

Answer 20

Hypoperfusion
Acute ocualr hypotensive crisis. Need a nocturnal reduction in BP
Defective autoregulation

Question 21

NAION: static form

Answer 21

75%

• acuity 20/40-20/200
• better VA than arteritic
• altitudinal VF defects is classic
• affluence defects

Question 22

NAION: progressive form

Answer 22

25%

• stepwise reduction in vision
• steady decline (weeks to months)
• VF defects much more variable
• afferent defects

Question 23

NAION disc appearance

Answer 23

Segmental to complete optic disc edema

Resolved NAION shows disc pallor, but does not tend to show disc excavation

Question 24

Fellow eye invovlemt in NAION

Answer 24

15-25% of patients over 5 years (up to 30 years)
More likely if diabetes, anemia, younger age
More likely if first <20/200 at onset

Question 25

Management of NAION

Answer 25

Most texts recommend observation since it is often too late to make a difference If caught early enough - systemic steroids - IV avastin - reduce IOP - blood thinners Surgical procedures - ON decompression - radial neurotomy - vitrectomy

Question 26

Ischemic optic neuropathy decompression trial results

Answer 26

6 months: not good outcomes After 24 months: not good outcomes Don’t recommend this surgery

Question 27

Macula and NAION

Answer 27

There could be some macular complications, so we would need to start treatment for them.

Question 28

DION (DM)

Answer 28

Type I or II Young or old Unilateral or bilateral Diabetic retinopathy usually present

Question 29

Bialteral DION DiffDx

Answer 29

Mimic papilledema

Question 30

Retrobulbar optic neuritis

Answer 30

No visible signs initially; pallor may ensue

Question 31

Optic neuritis profile

Answer 31

- any age - favorable prognosis - if onset of VA is 20/200 or worse, poor prognosis - devic’s disease usually progresses to poor vision

Question 32

Pathophysiology of Optic neuritis

Answer 32

- idiopathic - AI - infiltrative processes - infections - demyelination (MS, Devic’s are the most common causes)

Question 33

Papillitis in optic neuritis

Answer 33

-overlying vitreous cells may be present -mild to severe disc edema -mild to severe vascular engorgment 0spinter disco hemorrhages and peripapillary hemorrhages -edema nad exudates

Question 34

Retrobulbar neuritis

Answer 34

No visible disc signs

Question 35

Presentation of optic neuritis

Answer 35

Ocualr pain on eye movement - differentiates from other optic neuropathies - more common in retrobulbar neuritis

Question 36

Clinical course of optic neuritis

Answer 36

Initial VA is not predictive of outcome

Question 37

Adult optic neuritis

Answer 37

``` Unilateral Retrobulbar EOM pain Most often idiopathic High probability of recurrent demyelainting event and MS ```

Question 38

Pediatric optic neuritis

Answer 38

Bilateral Papillitis HA Most often post infectious or post immunization Low probability of recurrent demyelination gets event and MS

Question 39

Presentation of optic neuritis and MS

Answer 39

- most often retrobulbar - maybe assorted with periphlebitis - typically tenderness of globe on OEM - recurrent pattern

Question 40

Overall odds ratio of developing MS after optic neuritis

Answer 40

50%

Question 41

Optic neuritis treatment trial

Answer 41

- optic neuritis treatemtn trial found that most patients recover with or without therapy - IV plus oral therapy speeds the recovery of optic neuritis, reduces the risk fo MS development for the first two years, but does not offer any long term benefit regarding visual outcome or development of MS

Question 42

Managment of optic neuritis

Answer 42

Patient should be counseled that visual prognosis is good with or without treatment MRI recommended to ascertain future risk -if abnormal disease modifying therapy should be considered to lower conversion to MS

Question 43

Devic’s disease

Answer 43

Optic neuritis plus 2 of the following - lesions expending over 3 vertebrae of spine - absence of MRI findgins indicating MS at onset - IgG serum autoantibodies against AQP4

Question 44

High ICP and optic neuropathy

Answer 44

Papilledema

Question 45

Papiledmea

Answer 45

- bialteral optic disc edema due to increased ICP - any age - visual function preserved but may suffer reduction in chronic cases - mass lesions - medications - lead toxicity - HTN - blood dyscrasias

Question 46

Presentation of papilledema

Answer 46

V A generally preserved If it is reduced, its an emergency (either way it is an emergency)

Question 47

Acute papilledema fundus signs

Answer 47

Bialteral optic disc edema, may be assymetricla Generally marked elevation: Halo and Patons line

Question 48

Presentations of papilledeam (acute)

Answer 48

Blind spot enlargement

Question 49

Chronic papilledema

Answer 49

Blind spot enlargement Loss of central acuity from optic atrophy Optociliary shirt vessels

Question 50

Managment for papilledema

Answer 50

Immediate referral to neurologist for PCP for MR/CT scan Serial lumbar puncture

Question 51

Pseudotumor cerebri

Answer 51

Often occurs in young females with recent weight gain Diagnosis of exclusion - negative MRI with normal to small ventricles - negative CSF analysis - normal CBC If normal weight consider - infection - sarcoidosis, SLE, MS, Reye