A 43-year-old restaurant manager was referred for a neuro-ophthalmology opinion in Adelaide in 2001. He had consulted a neurologist for neck pain, at which time computed tomography and magnetic resonance imaging scanning showed a well-circumscribed calcified lesion within the left optic nerve (Fig. 1). The signal void in the coronal view localized the lesion to the center of the optic nerve.
The patient gave a history of having been accidentally hit in the left eye by a baseball at age 7 in New York. The impact was severe, causing loss of consciousness. No medical records were available.
On our examination, his corrected visual acuity was 20/20, but there was a left relative afferent pupil. Ishihara color vision testing was normal OD; one error was made OS. A relatively diminished light intensity of only 60% was reported OS. Computerized visual fields showed inferior patchy loss consistent with an inferior arcuate scotoma, along with an enlarged blind spot. The optic disc OD appeared normal, but the optic disc OS showed diffuse pallor. There were no ocular adnexal abnormalities, proptosis, or limitations of eye movements. Ocular alignment was normal.
An 84-year-old man described having very poor vision OD since being involved in a motorcycle accident 50 years earlier, in which he recalled sustaining a right orbital injury.
On our examination, corrected visual acuity was hand movements OD and 20/30 OS. A relative afferent pupil defect was present OD. There was gross constriction of the visual field OD and a normal visual field OS. The optic disc OD was pale, whereas the optic disc OS was normal. There were no ocular adnexal or eye movement abnormalities.
Computed tomography demonstrated heavy calcification within the right optic nerve confined to the orbit (Fig. 2).
The striking optic nerve calcification in both cases is likely to reflect a secondary phenomenon after traumatic injury with hemorrhage. There are many reports of calcification in the brain and spinal cord after traumatic hemorrhage (1). Approximately 10% of patients who have sustained intracerebral hemorrhage demonstrated calcified lesions on follow-up radiologic studies in one report (2).
The main differential diagnosis is calcification within an optic nerve sheath meningioma (3,4). However, calcification in a meningioma is typically a tubular thickening involving the perimeter of the nerve, whereas in our cases, the full thickness of the nerve was calcified. Furthermore, the visual acuity and field defects in both cases had remained stationary for many years, which would be atypical for meningioma. Idiopathic calcification of the dura and optic nerves has been reported (5,6), but perhaps such idiopathic cases represent missed trauma or meningioma (7).
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4. Saeed P, Rootman J, Nugent RA, et al. Optic nerve sheath meningiomas. Ophthalmology
5. Murray JL, Hayman LA, Tang RA, et al. Incidental asymptomatic orbital calcifications. J Neuroophthalmol
6. Phadke RV, Agarwal P, Sharma K, et al. Idiopathic duro-optic calcification-a new entity? Clin Radiol
7. Moseley I. Idiopathic duro-optic calcification (letter). Clin Radiol