乙胺丁醇中毒性视神经损害

Optic nerve neuropathy by ethambutol toxicity

目的探讨乙胺丁醇中毒性视神经损害的诊断和防治。方法通过对１７例服用乙胺丁醇后发生视神经损害的结核病患者的临床表现和诊断、分型的分析，对不同日剂量组的损害发生时间和程度的比较，以及损害发生后不同时间进行眼科诊疗效果的比较，总结防治乙胺丁醇引起视神经损害的更有效方法。结果１７例均有服乙胺丁醇史，主诉为视朦，视力、眼底、视野及色觉异常为体征，本病诊断成立。据损害部位分型轴型７例、轴旁型２例、混合型３例、不定型５例，无视网膜炎型病例。各日剂量组视力损害发生时间比较Ｐ＜０．００５，损害程度比较Ｐ＜０．００２５，视野及色觉损害也随日剂量增大而加重，显示视功能损害与日剂量成正比。治疗以血管扩张剂、神经营养剂为主；发生损害１５天内治疗者（８例）恢复视力平均为１．２，＞３０天者（６例）仅达０．３９（Ｐ＜０．０２）；视野和色觉１５天内治疗者全部恢复正常，＞３０天治疗者仅１例达正常。结论应高度警惕、预防乙胺丁醇损害视神经，小剂量应用乙胺丁醇并定期行眼科检查、监测视功能可避免或减少损害。一旦发现异常，应据病史、症状、体征明确诊断，立即停药，及时行眼科治疗。

Objective To investigate the clinical manifestations, treatment and prevention of optic nerve damage by ethambutol toxicity. Methods Retrospective analysis was done on 17 patients of tuberculosis who had been treated with ethambutol and shown ocular symptoms. Results Changes in visual acuity, fundal appearance, visual field and color sensation were major abnormal findings. According to the neural damage, the patients were diagonosed as axial neuritis 7 cases, periaxial neuritis 2 cases, mixed type 3 cases and there were no significant changes on fundus, color sensation or visual field in 5 cases. In 17 cases, none of the patient showed the appearance of retinitis. The impairment of visual acuity and the duration of damage were related to the daily dosage significantly. After stop of ethambutol and vasodilators or neurotrophic drugs were given, the function of optic nerves were recovered. Conclusions To prevent the damage of optic nerves by the toxicity of ethambutol, the appropriate small dosage of ethambutol is recommended, regular examination and monitoring of visual function is necessary. The physicians should be fully aware of the diagnosis and clinical manifestations of ocular toxicity of ethambutol, as soon as the diagnosis is made, ethambutol should be stopped immediately and appropriate therapy should be given.