Content by: Suhani Jain, Gowri S. Nair
Design by: Manan Chawda
A 41-year-old Female patient presented to the Ophthalmology department with sudden-onset right eye temporal vision and field defect, which was progressive for the last 2-3 months.
Upon presentation, the patient’s vision was a 6/6. Use glasses for distant vision. A mild Migraine was present. No weakness of limbs, tinnitus, giddiness, swaying while walking, tingling, numbness, shock-like sensations.
Goldman Perimetry: Visual field grossly constricted in RE
Dilated fundus examination: RE Temporal disc pallor (optic atrophy)
Relative afferent pupillary defect
Due to the nature of the findings, a neurological pathology was suspected, and the patient was referred to the Neurology department. The visually evoked potential was conducted, which showed bilateral optic neuropathy, which narrowed the diagnosis to one of Optic neuropathy.
An MRI of the brain was normal; however, an MRI of the orbit was confirmatory in diagnosing an Optic Nerve Sheath Meningioma.
CASE DISCUSSION
Optic nerve sheath meningiomas (ONSM) are rare benign tumours of the central nervous system. Accounting for just 2% of all orbital tumours and 2% of all meningiomas. It usually affects middle-aged females with a median age of 41 years. The mortality rate of this tumour is 0%. Patients usually manifest with vision loss and optic disc atrophy. Although their growth is slow but progressive, their location is critical as it directly affects the anterior visual pathway and can lead to severe visual loss. The clinical presentation and prognosis of ONSMs can vary and largely depend on the tumour’s location and the histologic type. Overall, the diagnosis is based on clinical presentation, examination, and neuroimaging findings. Nevertheless, delays in diagnosis or misdiagnosis are not uncommon and can result in higher morbidity rates. Treatment of this condition is still considered controversial, as the tumour’s proximity to the optic nerve makes it difficult to remove it without secondary complications and sequelae. This case underlines the importance of neurological pathology manifesting as a visual defect, i.e., the Eye is the window to the Brain.
Reference: Charpentier P. Total recovery of optic nerve sheath meningioma [Internet]. U.S. National Library of Medicine; 2016.