Optometry case study: Bilateral optic nerve swelling in a young child

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By Jonathan Tolentino, Specsavers Rouse Hill, NSW

History

Px: Middle Eastern female aged 2 years 8 months
Reason for visit: Routine eye examination. First eye examination. Mother was concerned because father was of a ‘high prescription’.
GH: No systemic conditions, normal pregnancy, developmentally sound – reaching developmental milestones at expected times
POH: No ocular injuries / surgeries
FOH: Father is high hyperope

Examination

Retinoscopy: R&L +1.25DS
MEM: R&L +1.25DS
Pupils: PERRLA, no RAPD
Ocular motilities: Good tracking to all gazes, no pain, slight head movement
Cover test: Ortho distance and near
External eye examination (direct observation): No abnormalities OU
Fundus examination (undilated BIO): Swollen optic nerves OU, macula flat with foveal reflex OU, periphery clear OU, media clear

Differential Diagnosis

  • Optic neuritis (with papillitis)
  • Papilloedema (NB: papilloedema is reserved for isolated bilateral optic nerve swelling due to idiopathic intracranial hypertension)
  • Bilateral optic nerve swelling (due to intracranial space occupying lesion or other)
  • Retinal vein occlusion
  • AION
  • Compressive / inflammatory / infective optic neuropathy
  • Traumatic optic neuropathy
  • Toxic / metabolic optic neuropathy

Management

Given the appearance of the optic nerves, further history was taken with specific emphasis on headaches. After questioning, the mother revealed the patient had been experiencing headaches for 6-7 weeks, initially as a 9-day period of daily headaches associated with nausea and vomiting.

Despite the limited communication, it was noted that she was experiencing the headaches in the middle of her forehead. They had presented to the emergency department of a local hospital where the symptoms were diagnosed as “virus without fever”. The nausea and vomiting continued after the patient was discharged from the hospital but by then it was occurring once or twice a week. It mostly happened during the night, with the patient often waking up vomiting. It was reported that she would be quite lethargic the following day.

An immediate referral was organised to a private ophthalmologist who subsequently referred the patient to a hospital emergency department. MRI showed a large left cerebellar tumour with secondary obstructive hydrocephalus, and surgery was scheduled for the following day with a paediatric neurosurgeon. The tumour was determined to be a juvenile pilocytic astrocytoma, which was completely removed with good recovery and no neurological deficit. The papilloedema was expected to improve completely as the hydrocephalus was relieved.

Discussion

Guided history-taking is important in all cases. It is important to conduct a full eye examination (notably a form of funduscopy), regardless of history of medical examinations or lack of imaging equipment, particularly in those difficult patients such as young children, mentally handicapped patients, or any uncooperative patients.

Juvenile pilocytic astrocytoma is a rare childhood brain tumour occurring in the first two decades of life. Most cases are often slow growing and benign, and do not spread to surrounding brain tissue. Symptoms may be varied, but being an intracranial space-occupying lesion, symptoms related to increased pressure in the brain may be exhibited, including headaches, nausea, vomiting, balance problems, lethargy, drowsiness, or changes in personality or mental status. Ocular signs include bilateral disc swelling, nystagmus and diplopia, and in some cases, sixth and seventh cranial nerve palsies may occur.

Bilateral optic nerve swelling in either children or adults is a medical emergency that requires urgent referral to ophthalmological care. It can indicate a number of different inflammatory, infectious, toxic, metabolic, genetic or vascular conditions. Early intervention reduces possible long-term damage, as chronic optic nerve swelling can lead to constriction of visual fields and loss of central visual acuity.

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