| Autor: |
Hickman, S.J., Kupersmith, M.J., Straga, J., Egan, R., Kraker, R., Lefton, D., Miszkiel, K.A., Miller, D.H., Plant, G.T. |
| Předmět: |
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| Zdroj: |
Neuro-Ophthalmology; Sep2002, Vol. 28 Issue 2, p69-76, 8p |
| Abstrakt: |
Aim: To determine whether an upper temporal visual field defect can occur in the asymptomatic fellow eye of patients with acute optic neuritis affecting the posterior optic nerve, suggesting involvement of contralateral crossing fibres (a concept originally proposed by Wilbrand). Methods: A retrospective analysis was performed on 135 patients from two cities with acute optic neuritis. Perimetry results were reviewed to determine whether there was an upper temporal visual field defect in the contralateral healthy eyes of those patients with posterior optic nerve enhancement on gadolinium-enhanced magnetic resonance imaging. Results: Abnormal enhancement of the intracranial optic nerve immediately anterior to, but not including, the optic chiasm was seen in nine patients. Of these, two cases exhibited superior temporal visual field defects in their contralateral healthy eyes. Repeat examination 12 days later in Case one and 24 days later in Case two revealed resolution of these defects. Conclusions: An acute lesion of the posterior optic nerve in optic neuritis can occasionally give rise to an upper temporal visual field depression in the asymptomatic fellow eye in the apparent absence of chiasmal involvement. These cases could indicate the involvement of crossing fibres which are 'junctional' in the sense that they follow a course closely associated with the junction of the posterior optic nerve and chiasm. Whether or not such fibres cross the junction into the posterior optic nerve, as suggested by Wilbrand, hut recently refuted by Horton, the localising value of such field defects remains clinically significant. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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