視神經炎發生於患有全身性紅斑狼瘡合併泛視神經脊髓炎之患者並不多見。我們報告一位24歲女性主訴右眼有進行性的視力減退5天，同時伴隨著眼睛疼痛。她有全身性紅斑狼瘡之病史但控制良好。她的右眼視力減退至僅可辨手動。右眼視神經炎為初步診斷，給予脈衝類固醇治療3 天，然後轉為口服類固醇緩慢減量。進一步評估顯示陽性抗水通道蛋白4抗體，所以加強其免疫抑制劑之使用。她的視力在治療後進步到20/25。對於全身性紅斑狼瘡合併視神經炎之病患，檢測抗水通道蛋白4抗體是必要的。儘管目前尚無法對這類病例做出具體的治療結論，但應早期給予類固醇，並考慮是否給予預防復發之治療方針。

Optic neuritis (ON) in a patient of systemic lupus erythematosus (SLE) overlapping with neuromyelitis optica spectrum disorder (MNOSD) was a rare occasion. We presented a 24-year-old female with the complaint of progressive visual loss associated with eye pain in the right eye for 5 days. She had past history of SLE with well control. Her vision decreased to hand motion. Right optic neuritis was impressed after ocular examination. Pulse steroid for 3 days was given and followed by slow tapering oral steroid. Further evaluation revealed positivity of AQP4-IgG and immunosuppressive therapy was augmented. Her vision improved to 20/25 after treatment. The presence of ON in a patient of SLE should warrant the testing for AQP4-IgG. Although there are no specific recommendations for the treatment of SLE/ MNOSD overlapping cases, early pulse steroid was necessary. Long term immunosuppression should be considered as an effective way to attack prevention.