Optometry case study: A classic presentation of benign intracranial hypertension

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By Noni Rupasinghe, Specsavers Sale, VIC

History

Px: 19-year-old female
Reason for visit: Presented for routine biennial check-up. Patient had been getting increasing migraines which she thought were a result of her driving and studying frequently.
GH: Overweight, but no other health issues, no medication
POH: No ocular issues
FOH: No relevant issues

Clinical Assessment

Unaided vision:
RE: 6/6-1      LE: 6/7.5

Subjective refraction:
RE: +0.50/-0.25 x 80  6/4.8      LE: +0.75/-0.25 x 75  6/4.8

Ocular motility: Full and smooth with no double vision or pain

Pupils: Unusually slow pupil constriction to light

Anterior eye examination: Normal results for both eyes

Posterior eye examination: Significant bilateral swelling of the optic discs (Figures 1 and 2). Macula and peripheral retina were normal in both eyes.

Visual fields: Presented with an enlarged blind spot more prominent in the RE than the LE, with some almost arcuate-like defects (Figures 3 and 4).

Diagnosis

Differential diagnosis:

  • Benign or idiopathic intracranial hypertension with papilloedema
  • Optic disc drusen
  • Central retinal vein occlusion
  • Optic neuritis

Management

Given the noticeable signs of bilateral optic nerve swelling and her symptoms of increasing migraines, it was important to refer this case urgently for further ophthalmic investigation. The patient was referred to a specialist hospital where an urgent MRI scan of the head and orbits was taken. MRI scans may show optic nerve enlargement, flattened posterior globe appearance, and occasional optic nerve head protrusion as signs of papilloedema.

After excluding a structural intracranial lesion, a lumbar puncture was performed to measure the cerebrospinal fluid opening pressure, which was measured to be 36cm H20. A neuro-ophthalmologist diagnosed the condition to be benign intracranial hypertension (BIH) with papilloedema. The patient was discharged a few days later and prescribed acetazolamide to provide further symptomatic relief.

Discussion

BIH is a condition characterised by increased intracranial pressure without any known cause1. Papilloedema causes a number of effects on the visual system as it leads to the dysfunction of the nerve fibre due to swelling2. Individuals may not always present with visual symptoms, but if untreated, BIH can lead to loss of optic nerve function and retinal dysfunction2.

As this patient was overweight and experiencing symptomatic headaches, this was a typical presentation of BIH with papilloedema3. This case highlights the importance of fundoscopy, retinal imaging and visual field assessments as these tests emphasised the need for urgent referral. Patients should be referred immediately to the emergency department as it may indicate a potentially serious underlying disease3. Further investigation is essential as neuroimaging and lumbar puncture procedures aid with differentiating diagnoses such as optic tumors, optic neuritis and pseudopapilloedema3.

Due to the need for further radiological investigation to accurately diagnose BIH, practitioners should be prompted to urgently refer for neuro-ophthalmological assessment – regardless of the patient’s symptoms – if bilateral optic nerve swelling is noted. This allows for the appropriate course of treatment to be undertaken to alleviate the patient’s symptoms.


REFERENCES

  1. Digre K. Not so benign intracranial hypertension. BMJ. 2003;326(7390):613-614.
  2. Schirmer C, Hedges T. Mechanism of visual loss in papilledema. Neurosurg Focus. 2007;23(5):1-8.
  3. Mollan S, Markey K, Benzimra J, Jacks A, Matthews T, Burdon M, Sinclair A. BMJ. 2014: 14: 380-390
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