Optic Nerve/Neuro Flashcards Preview

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Flashcards in Optic Nerve/Neuro Deck (38):
1

Hyaloid Remnants/Persistent Hyaloid Artery

- incomplete regression (usually done by 8 months)
- asymptomatic
- rare for vitreous hemorrhage

2

Prepapillary Vascular Loops

- unilateral, arterial and embryonic in nature

Management:
- routine

3

Congenital Macrovessels

- enlarged single vessel crossing the horizontal raphe

Management:
- recognition of leakages

4

Cilioretinal Vessels

- usually derived from short posterior ciliary artery system or choroidal vascular system
- positioned temporally, hooking out of papillomacular bundle
- may remain patent even during CRAO because it is a different system

Management:
- routine eye examination
- occlusion may indicate giant cell arteritis

5

Myelinated Nerve Fibres

- represent the continuation of normal myelinated tissue anterior to the lamina cribosa
- superficial retinal opacification with feathered edges
- may create visual field loss at threshold

Management:
- rule out CWS`

6

Choroidal Crescent

- darker crescent due to absence of retina

7

Scleral Crescent

- lighter/white crescent due to absence of choroid and retina
- may be associated with ROP, ectasia and sickle cell proliferation

8

Circumpapillary Staphyloma

- usually unilateral
- area around the disc is depigmented and may have pigmentary migration
- variably reduced vision or constricted fields
- differential diagnosis helped with utlra sound

Management:
- patient education and provision of safety eyewear
- routine eye examinations indicated

9

Coloboma

- absence of tissue due to failure of fetal tissue to close

- affected nerve head always larger than its fellow, unusual looking
- usually inferior portion affected with significant excavation and surround of pigment hyperplasia
- reduced VA and VF defects variable but present
- associated with systemic abnormalities
- associated with non-rhegmatogenous retinal detachment and rhegmatogenous in retinochoridal variety

Management:
- rule out systemic abnormalities
- protective eyewear
- ed RD

10

Morning Glory Disc

- unilateral, affected head larger than its fellow
- unusual vascular pattern radiating from disc
- unilateral? severe vision loss. bilateral? mild-moderate.
- strong association with non-rhegmatogenous detachment

Management:
- rule out systemic involvement with neurological consultation
- ed on RD

11

Congenital pits of the ONH

- affected disc larger than its fellow
- pit usually inferior temporal with VF loss
- often associated with RPE disruption adjacent to ONH/reactive hyperplasia secondary to tugging of retinal tissue
- strong association with non-rhegmatogenous retinal detachment
- possible inheritance pattern

Management:
- Amsler grid to monitor vision
- Ed RD

12

Congenital optic nerve head hypoplasia

- ONH 1/2 to 1/3 smaller than fellow eye
- stronger association with astigmatism
- reduced vision due to maldevelopment of NFL
- variable VF defects (nasal or altitudinal)
- associated with multiple systemic abnormalities especially if bilateral
- present in 50% of fetal alcohol syndrome

Management:
- rule out so it's not treated as amblyopia
- rule out systemic abnormalities
- communication with other health care providers

13

Megalopapilla

- unilateral enlarged disc of congenital nature secondary to abnormal development of primitive epithelial papilla
- may stimulate asymmetric C/D of glaucomatous optic atrophy

Management:
- benign condition so just annual eye examinations

14

Buried Drusen

- inherited in an autosomal irregular pattern
- calcium-like deposits anterior to lamina cribosa
- deposits can shear blood vessels, cause hemes,

15

Optic Neuritis

- young female (20-45)
- MS associated
- unilateral, sudden, painful vision loss (VA 20/20 to NLP)
- (+) RAPD
- decreased vision sensitivity, VF defects
- VA may return to normal/near normal over 2-3 months although will have permanent reduced CSF and optic nerve pallor.

16

Risk of developing MS after episode of optic neuritis?

15 year risk: 50%

72% if one or more white matter lesions are present on MRI, 25% if none.

17

What are causes of optic neuritis?

- idiopathic
- Syphilis
- Cat-scratch disease
- Lyme disease
- Meningitis
- Sarcoidosis
- Systemic lupus erythematosus
- Devic's disease (has no white lesions)
- optic neuritis AND myelitis (spinal cord)

18

Uhthoff's phenomenon

Transient vision loss with increased body temperature (i.e. exercise). Highly characteristic of multiple sclereosis. Only occurs in 6% of patients though.

19

Arteritic AION (AAION)

- secondary occlusion of the short posterior ciliary arteries, most commonly due to giant cell arteritis (GCA)
--> systemic inflammation of the medium/large blood vessels
- commonly occurs at age >55 years
- elevated ESR, CRP and platelet count

- Elevated ESR and CRP are 97% specific to GCA

20

Leber's optic neuropathy

- hereditary condition that occurs from mutations in mitochondrial DNA that are inherited from the mother.
- usually male and onsent in late teens/early 20s
- commonly starts with one eye and sudden onset of decreased VA (20/200 to CF), before affecting other eye

Early signs; optic disc edema, disc hyperemia, telangiectatic vessels on surface of optic nerve

Late signs: optic disc atrophy

Conditions may spontaneously improve in 35% of cases.
No treatment.

21

Optic nerve sheath meningioma

- most common in young to middle-aged women
- generally benign, unilateral tumours that result in compression of optic nerve with resulting optic disc edema, followed up optic atrophy and progressive vision loss

Treatment:
- observation, radiation, and/or surgery

22

Ocular myasthenia

- autoimmune antibodies against acetylcholine receptors in the neuromuscular junction
- results in weakness and fatigue
- Graves' and Myasthenia can co-exist
- decreased innervation to levator and EOM results in ptosis and diplopia
- signs are variable and worse at end of the day due to patient fatigue

23

Von Graefe's sign

Upper lid lag during downgaze

24

Kocher's sign

Globe lag compared to eyelid movement during upgaze/lid retraction on gaze

25

Dalrymple's sign

Upper eyelid retraction with upper sclera showing resulting in stare appearance

26

Lagophthlmos

Incomplete lid closure.

27

Bell's phenomenon

Eye deviate up and outwards with forced lid closure

28

Pituitary adenoma is associated with?

- bitemporal hemianopia
- amenorrhea
- galactorrhea
- infertility
- loss of libido

29

Causes of chiasmal lesion

- suprasellar meningioma
- internal carotid artery aneurysm
- craniopharyngiomas
- gliomas

30

Macula-only homonymous visual field defects should..?

Be imaged for compressive lesions.

Unlikely due to stroke reasons because of dual supply from middle cerebral and posterior cerebral arteries.

31

Junctional scotoma

Temporal defect respecting the midline in "good" VA eye, and central/diffuse visual field defect in the fellow eye.

32

Foster Kennedy Syndrome

Optic atrophy in one eye and optic edema in the other.. Tumour within the frontal lobe.

VF often normal in the edematous nerve, but central VF loss in atrophy.

33

Macula-sparing homonymous hemianopia
(spares at least central 5 degrees in both eyes)

Most commonly due to stroke because macula fibers receive dual blood supply.

34

Raised optic nerve differentials

1. Papilledema
2. Compressive optic neuropathy
3. Optic neuritis: papillitis
4. Central Retinal Vein Occlusion
5. Ischemic Optic Neuropathy

35

Papilledema causes

1. papilledema
2. idiopathic intracranial hypertension
3. increased intracranial hypertension from space ocupying lesion in brain

36

Idiopathic intracranial hypertension

- abnormal CSF opening pressure (>250mmH20)
- refer to neuro-ophth

GOALS:
1. preserve vision
2. decrease headaches

37

Causes for space occupying lesions:

- intracranial mass
- sinus thrombosis
- spinal cord mass

38

Compressive optic neuropahy

Occurs when a lesion compresses along the optic nerve usually from within the orbit.

From globe to chiasm.
-chalked pale nerve