Primary tumor of the optic nerve

一、optic glioma

* 最常見的optic nerve primary tumor
* 患者非常年輕（70%在10歲以前，90%在20歲以前）
=> opitc nerve sheath meningioma的患者較老（中年阿姨多）

* 症狀以proptosis最多（94%），次為visual loss (87%)
=> optic glioma的proptosis比較明顯！而optic nerve sheath meningioma只有mild proptosis。

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二、optic nerve sheath meningioma
* 第二常見的optic nerve primary tumor
* benign tumor
* 常見於40-50歲adult，female居多 (3:1)
* Classic Diagnostic Triad
1. Painless, slowly progressive monocular visual loss
2. Optic atrophy ( or swelling of the disc)
3. Occasionally, optociliary shunt vessels (retinochoroidal collaterals)

* Minimal to mild proptosis （Proptosis很不明顯！與optic glioma區分！）

* 若tumor往前延伸，可見disc edema
* Mild ocular motility
* 通常不需要Biopsy
=> 原因：biopsy不準確、造成多餘傷害、結果與tumor behavior無關

* Optic nerve sheath meningioma沒有marked proptosis (optic glioma有)