背景與目的：傳統測試對於眼肌型肌無力症(ocular myasthenia gravis, OMG)之診斷率大約都只有5 到7 成。眼科的冰敷測試診斷率雖可達80%，唯其肌力評估過於粗糙，且未詳細追蹤臨床病程。方法：本研究收集14 例有眼皮下垂或眼肌無力病人，符合症狀波動及早晚差異特性，完成edrophonium、重覆電刺激、單纖維肌電圖、乙醯膽鹼受體抗體及冰敷共5 項測試。結果：單纖維肌電圖在11 例中8 例(73%) 不正常。抗體在11 例中6 例(55%) 為陽性。13 例中7 例(54%) edrophonium 測試為陽性，14 例中5 例(36%) 冰敷測試為陽性，重覆電刺激在11 例中僅2 例(18%) 不正常。此5 項診斷工具中，僅有1 項異常有5 例，2 項異常6 例，3 項異常1 例，4 項異常2 例。上下眼皮間距(interpalpebral distance, IPD) 在edrophonium測試後平均增加1.9mm，冰敷測試後平均增加1.3 mm。抗體陰性組中，edrophonium 測試IPD 值變化愈大，單纖維肌電圖值較低(p 值0.020)。抗體陽性組的單纖維肌電圖值顯著高於抗體陰性組(p 值0.020)。結論：單纖維肌電圖應是OMG的最敏感診斷工具，依次為抗體，edrophonium測試，冰敷測試，重覆電刺激。

Background and Purpose: The sensitivities of traditional diagnostic tests for ocularmyasthenia gravis (OMG) are around 50%~70%. The ice pack test developed by ophthalmologistswas reported to have over 80% diagnostic accuracy for OMG. However, the less-objectiveevaluation with ptosis and limited description of the clinical course jeopardize the universalacceptance of this test for OMG. Methods: We applied 4 sets of diagnostic tests to 14 OMGpatients including the edrophonium test, repetitive nerve stimulation (RNS), single-fiberelectromyography (SFEMG), acetylcholine receptor antibody (AchRAb), and ice pack test.Results: Eight of 11 patients (73%) had an abnormal SFEMG test. AchRAbs were positive in 6 of11 patients (55%) . The positive rates were 54%(7 of 13 patients) for the edrophonium test, 36% (5of 14 patients) for the ice pack test, and 18% (2 of 11 patients) for the RNS test. Only 1 test wasabnormal in 5 patients, 2 were abnormal in 6 patients, 3 were abnormal in 1 patient, and 4 wereabnormal in 2 patients. The mean increases in the interpalpebral distance (IPD) were 1.9 mm forthe edrophonium test and 1.3 mm for the ice pack test. The increases of the IPD in seronegativepatients were inversely correlated with the jitters (p = 0.020) . The jitterswere significantly higherin seropositive patients compared to their seronegative counterparts (p = 0.020) . Conclusions:The diagnostic sensitivity for OMG patients was best with the SFEMG, followed by AchRAb,edrophonium test, ice pack test, and RNS.