Categories
Nervous system Ocular System

Papilledema

Optic disc oedema secondary to high intracranial pressure (ICP).

  • Papilledema is frequently bilateral & symmetric but may be asymmetric or unilateral

Other causes of disc oedema:

  1. Inflammation
    • Papillitis, Neuroretinitis, Papilophebitis, Uveitis
  2. Ocular hypotony
    • Any cause
  3. Vascular causes
    • CRVO, Diabetic Papillopathy, Uremia, Anterior Ischaemic Optic Neuropathy (AION)
  4. Orbital causes
    • Tumours, Grave’s orbitopathy, orbital cellulitis
  5. Infiltrative conditions
    • Leukaemias, Lymphomas

Etiology

Causes of increased intracranial pressure (ICP):

  • Space-occupying lesions:
    • Intracranial mass
    • Abscess
    • Hemorrhage
    • Arteriovenous malformation
  • Focal/diffuse cerebral oedema:
    • Trauma
    • Toxic
    • Anoxia
  • Reduction in size of the cranial vault:
    • Craniosynostosis
    • Thickening of skull
  • Blockage of CSF flow:
    • Non-communicating hydrocephalus
  • Reduction in CSF reabsorption:
    • Communicating hydrocephalus
    • Meningitis
    • ↑ cerebral venous sinus pressure
    • ↑ CSF protein
  • Increased CSF production
  • Idiopathic intracranial hypertension (IIH) (predominantly affects obese women of childbearing age)

Pathogenesis

Hayreh’s theory:

Papilloedema develops due to axoplasmic flow stasis in the prelaminar region of the optic disc, due to an alteration in the pressure gradient across the lamina cribrosa.
  • Retrolaminar area disturbances: Increased intracranial pressure, malignant hypertension, orbital lesions
  • Prelaminar area disturbances: Ocular hypotony
  • Steps:
    1. Axonal Swelling
    2. Venous Congestion
    3. Extracellular Oedema

Presentation

Symptoms due to raised ICP:

  • Headache (worse in morning)
  • Associated projectile vomiting

Ophthalmologic manifestations:

  • Normal vision (papilledema does not lead to vision loss but can result in secondary optic atrophy which results in vision loss)
  • Amaurosis fugax (due to blockage of axoplasmic transport): Transient vision loss
  • Enlargement of blind spot

Mechanical obstruction:

  • Blurring of optic disc margins (earliest sign)
  • Elevation of optic disc
  • Edema in retina nerve fiber layer
  • Paton’s lines: Radial retinal lines cascading from optic disc

Vascular congestion:

  • Hyperemia of optic disc
  • Venous engorgement
  • Cotton wool spots
  • Splinter hemorrhages over and/or adjacent to the optic disc
  • Macular star appearance of exudates
Funduscopic findings of papilledema
Funduscopic findings of papilledema include engorged and tortuous retinal veins, a hyperemic and swollen optic disk, and retinal hemorrhages around the disk. A swollen optic disk is suggested by disk elevation, loss of the optic cup, and obscuration of the fine vessels on the optic nerve surface. | James Garrity, MD.

Stages:

  1. Early (incipient) papilloedema
  2. Established (fully developed) papilloedema
  3. Chronic (vintage) papilloedema
  4. Atrophic papilloedema (postneuritic optic atrophy)
Chronic papilledema
Chronic papilledema: The optic nerves remain elevated with blurred margins, with feathering of the retinal nerve fiber layer. The nerve can become more atrophic and pale. Retinochoroidal (optociliary) shunt vessels can form due to the chronic outflow obstruction (black arrow in left image). Refractile bodies representing lipid exudates can also be seen (black arrow in right image). | Acheson JF. Idiopathic intracranial hypertension and visual function. Br Med Bull. 2006;79-80:233-244.

Diagnosis

Modified Frisens Scale:

  • Grade 0 (Normal): Normal disk with blurring of nasal and temporal disk; the cup is maintained, and there is no obstruction of retinal vessels
  • Grade 1 (Minimal): C-shaped blurring of the superior, nasal, and inferior disk borders; the temporal margin is usually normal
  • Grade 2 (Low-degree): 360-degree elevation of the disk margin
  • Grade 3 (Moderate-degree): Entire disk elevation with partial obscuration of one or more retinal vessels at the disk margin
  • Grade 4 (Marked): Complete obliteration of the cup and complete obscuration of at least some vessels on the surface of the disk. Small, dilated telangiectatic capillaries may be seen on the disk
  • Grade 5 (Severe): Dome-shaped disk appearance, with all retinal vessels obscured
Frisen stages (0 – 5) of papilledema
Frisen stages (0 – 5) of papilledema | Evaluation and treatment of papilledema in pregnancy – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Frisen-stages-0-5-of-papilledema-Refer-to-Table-1-for-staging_fig1_6786445 [accessed 14 Feb, 2019]

Differential diagnosis:

  • Papillitis: Inflammation of the Optic Nerve Head
  • Pseudopapillitis
FeaturePapilloedemaPapillitisPseudopapillitis
1. LATERALITYUsually bilateralUsually unilateralUnilateral/Bilateral
2. SYMPTOMS
Visual AcuityAmaurosis fugax

 

Later vision decreases due to optic atrophy

Marked loss of vision, sudden onsetDefective vision depending on degree of refractive error
Pain and TendernessAbsentMay be present with ocular movementsAbsent
3. FUNDUS EXAMINATION
MediaClearPosterior vitreous hazeClear
Disc colourRed and juicyMarked hyperaemiaReddish
Disc marginsBlurredBlurredNot well defined
Disc swelling2-6 dioptres≤ 3 dioptresDepending on degree of hypermetropia
Peripapillary oedemaPresentPresentAbsent
Venous engorgementMore markedLess markedAbsent
Retinal haemorrhagesMarkedUsually not presentAbsent
Retinal exudatesMore markedLess markedAbsent
MaculaMacula star may be presentMacula fan may be presentAbsent
4. FIELDSEnlarged blind spotCentral scotoma for more coloursNo defect
5. FLUORESCEIN ANGIOGRAPHYVertical pool of dye due to leakageMinimal leakageNo leakage

Management

  • Emergency hospitalisation
  • Urgent neuroimaging (CT scan/MRI with gadolinium enhancement)
  • Treat underlying cause
  • Bad visual prognosis

Leave a Reply