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A 35 year old woman is found to have a best-corrected visual acuity of 20/50 (6/15, 0.40) in her left eye and 20/20 (6/6, 1.0) in her right eye on a routine optometric examination. Formal visual fields show a nerve fiber bundle defect in the affected left eye and a normal visual field in the right eye. There is an afferent pupil defect in the left eye, but otherwise the examination of both eyes is normal, including the appearance of both optic discs on ophthalmoscopy. Brain/orbit MRI shows this isolated abnormality.

    • Review Topic

    You would tell the patient that

    A) This is an intracranial sphenoid ridge meningioma and that surgery has a better than 50% chance of improving vision in the affected eye and less than a 10% chance of harming vision in the unaffected eye

    Correct! The imaging features here are so characteristic of meningioma that biopsy is not needed for confirmation. Experienced skull-base neurosurgeons are achieving improvement in vision in over 50% of operated cases and causing no harm to the unaffected eye so long as they do not attempt to remove every bit of tumor! Primary x-irradiation may stop tumor growth and even shrink tumor size, but it rarely improves vision. It is an option if surgery is too dangerous or fails to remove enough tumor, or if tumor growth occurs after surgery. Avoiding any intervention is always an option if the patient is afraid of surgery or x-irradiation, but the chances of further tumor growth and vision loss are high, especially in such a young patient.

    B) This is a meningioma and that x-irradiation is favored over surgery because it has a better than 50% chance of improving vision and lower risks than surgery

    Incorrect

    C) This is likely a meningioma, but biopsy is needed to exclude other lesions

    Incorrect

    D) Delaying any intervention is best because both surgery and radiation have risks and vision is unlikely to worsen over time

    Incorrect