Papilloedema

Usually bilateral disc swelling secondary to raised ICP

Causes

• Mass effect

  • Tumour
  • Haemorrhage
  • Oedema

• Increased CSF: choroidal plexus tumour

• Reduced CSF drainage

  • Blockage of the foreman of Munro or Sylvian aqueduct (congenital or mass)

  • Damage to arachnoid granulations: meningitis, SAH

  • IIH

    • Drugs: tetracyclines, steroids (withdrawal), vitamin A derivatives (isotretinoin), nitrofurantoin, growth hormone, indometacin, cimetadine, nalidixic acid (one of the first synthetic quinolones)
    • Systemic disease: hypoparathyroidism, adrenal adenomas, renal failure, addison’s disease, OSA, COPD
    • Anaemia

  • Malignant hypertension

  • Cerebral venous sinus thrombosis

Clinical features

• Visual disturbance/obscurations

  • Transient repeated episodes
  • Sustained: implies irreversible damage
  • Field defects: enlarged blind spot

• Headache

  • Postural

• Nausea/vomiting

• Pulsatile tinnitus

• Disc swelling may not be present in early cases

  • May also be absent if the disc is structurally abnormal eg congenital anomaly, atrophic, high myope

• Sixth nerve palsy: stretching of the abducens over the petrous part of the temporal bone (false-localizing sign)

Staging

• Early

  • Hyperaemic (hyperaemia tends to persist until atrophy occurs)
  • Blurred/elevated margins
  • Subtle oedema
  • Dilated capillaries/veins
  • Absent SVP
  • Paton’s line: retinochoroidal folds around the disc
  • Preservation of the optic cup

• Acute (above plus)

  • Peripapillary haemorrahges
  • Cotton wool spots
  • Increased oedema obscuring the vessels
  • Macular changes: subretinal fluid
  • Normal or reduced VA
  • Enlarged blind spot
  • Macular fan in younger patients (not the same as macular star)

• Chronic

  • Less hyperaemic
  • Less cotton wool spots or haemorrhages
  • Elevated
  • Drusen-like deposits: pseudodrusen are believed to be exudates from extruded axoplasm of retinal ganglion cells
  • Collateral vessels at the disc
  • RPE atrophy

• Atrophic/late

  • Pale disc
  • Attenuated vessels
  • Gliosis

Tests

• Urgent neuroimaging with venography

  • Can also measure the calibre of the optic nerves (normal nerve sheath diameter is 5.5mm +/- 1mm)

• LP: normal opening pressure is less than 25cm/water

• FFA: if uncertainty about papilloedema: late leakage from the dilated disc capillaries

Pseudopapilloedema and congenital disc anomalies

Typically an asymptomatic patient: in 80% of normal patients there will be spontaneous venous pulsation

• Disc drusen

• Tilted discs

  • Superotemporally elevated

• Hypermetropic discs

  • Crowded and elevated

• Myopic discs

  • Nasally elevated
  • Leakage of FFA

• Myelinated peripapillary nerve fibres: the only cause of pseudopapilloedema which obscures the vessels

Tilted disc

• Typically bilateral but asymmetrical

• Optic nerve inserts obliquely into the globe

• Associated with myopia and astigmatism

• Bitemporal field defects that do not respect the vertical midline (cp with chiasmal lesions)

  • May resolve with refraction

• Elevation of the superotemporal rim and thinning of the inferonasal RPE/choroid

• Situs inversus of the retinal vessels

• Rarely associated with CNV or sensory macular detachment

Optic disc pit

• Rare, typically unilateral

• Herniation of the neuroectodermal tissue into the optic nerve

• Asymptomatic but complications associated with reduced VA and field defects (may mimic glaucoma)

• Grey pit in the temporal disc

• Larger than usual disc (and compared to fellow eye)

• Complications

  • Macular retinoschisis/serous retinal detachment: treated with IVT anti-VEGF, vitrectomy and gas tamponade. Consider optic disc pit in suspected CSR cases

• Spontaneous resolution in 25%

• Laser can be tried along margin

• Vitrectomy, ILM and gas tamponade

Disc drusen

• 0.5% prevalence in Caucasians, may be AD inherited

• Calcified deposits within the nerve

• May be associated with visual field loss (75%): may be progressive but rarely have a significant impact on vision

• Episodic visual blurring may be associated with transient ischaemia of the nerve

• Typically bilateral

• May become more obvious with age: in children buried drusen are hidden beneath the nerve fibre layer

• Absent cup

• NFL thinning

• Centrally emerging vessels

• Associations:

  • CNV
  • RP: often easier to detect drusen in RP patients
  • Angioid streaks +/- pseudoxanthoma elasticum (an inherited connective tissue disorder of elastin)
    • 75% of those with angioid streaks develop CNV
  • Alagille syndrome: autosomal dominant condition of the liver and heart
  • NAION
  • Optociliary shunts

• Drusen can be demonstrated on: ocular ultrasound, OCT, autofluorescence, CT

Causes of optociliary shunts

• BRVO/CRVO
• Optic nerve sheath meningioma
• Chronic glaucoma
• Chronic papilloedema
• Optic nerve head drusen
• Optic nerve glioma
• Arachnoid cyst of optic nerve
• Phakomatoses
• Diabetic retinopathy

Optic nerve hypoplasia

• Reduced axons in the nerve
• Important cause of reduced vision in newborns
• May be sectoral
• RAPD if unilateral
• Double-ring sign
• Associations:
  • Septo-optic dysplasia (‘de Morsiers’)
  • Midline CNS abnormalities: absent septum pellucidum, absent/dysgenic corpus callosum
  • Endocrine abnormalities: hypopituitarism

Optic disc coloboma

• Incomplete closure of the embryonic fissure (inferonasally)

• May be unilateral or bilateral

• Variable involvement of the neighbouring retina

• Sporadic or autosomal dominant (PAX6 gene)

• Associated with:

  • Trans-sphenoidal encaphalocoele
  • Chromosomal abnormalities
    • Patau: trisomy 13
    • Edwards: trisomy 18
    • Cat-eye: trisomy 22
  • Aicardi syndrome (X-linked dominant: fatal for males in utero), CHARGE, Walker-Warburg, Goltz, Goldenhar, Meckel-Gruber
  • Disc pit
  • Coloboma of the retina, ciliary body, iris
  • Microphthalmos and microcornea
  • CNV, serous retinal detachment

• If severe, may cause reduced VA (amblyopia) and field defects (superior)

• Glistening white bowl excavation within the disc

Morning glory anomaly

• Very rare: unilateral excavation of the posterior globe involving the optic disc (and sometimes macula)

  • May also be associated with PAX6

• Severely reduced VA

• Enlarged pink disc with pigmented annular zone surrounding

• Abnormally straight vessels arising like spokes (see image)

• Serous retinal detachment

• Systemic associations are rare:

  • Trans-sphenoidal encephalocoele
  • Moya-moya
  • PHACE syndrome

Myelinated nerve fibres

• Abnormal myelination of ganglion cell axons extending beyond the cribiform plate

• 1% of the population

• VA can be reduced if the macula is involved

• Not necessarily contiguous with the optic disc

• Obscures neighbouring retinal vessels

• Usually unilateral (80%)

• DDx: neoplastic infiltration

• Associated with myopia, anisometropia, strabismus and amblyopia

• Systemic associations

  • Neurofibromatosis
  • Down syndrome
  • Craniofacial dysostosis
  • Gorlin-goltz syndrome (Basal cell naevus syndrome)
  • High myopia

• Hyper-reflective RNFL on OCT