在结核病患者中通过评估解剖结构和视功能变化早期发现乙胺丁醇毒性

摘要

目的:通过评估比较治疗前后解剖结构和视功能的变化,包括视网膜神经纤维厚度、图形视觉诱发电位、传统视神经功能检查,早期检测乙胺丁醇毒性.方法:前瞻性研究,包括参加马来西亚理科大学医院的短期治疗观察项目的36例72眼结核病患者.视力和视神经功能检查由同一位研究者进行.同样,Humphrey自动视野检查、光学相干断层扫描(OCT)检查视网膜神经纤维厚度(RNFL)和图形视觉诱发电位(PVEP)均由同一位技术人员进行.在开始乙胺丁醇治疗前和治疗3 mo后各进行检查一次.结果:乙胺丁醇治疗前后视力、彩色视觉、光亮度、红光反射和眼底检查无明显改变.然而,平均视野缺损在治疗后较前变差(P=0.010).OCT和PVEP有显著变化,P100潜伏期延长、幅度降低,RNFL在各个象限均增厚(P＜0.05).结论:通过OCT检测RNFL厚度以及使用PVEP检测P100波峰潜伏期和幅度,可以在传统视神经功能检查异常之前,发现乙胺丁醇治疗后早期解剖结构和视功能的亚临床改变.%AIM:To evaluate if early ethambutol toxicity can be detected by comparing pre-and post-treatment anatomical and visual function using retinal nerve fiber thickness,pattern visual evoked potentials and conventional optic nerve function tests.METHODS:This was a prospective study involving 72 eyes of 36 patients treated with ethambutol according to directly observed treatment short-course(DOTS) strategy in Hospital Universiti Sains Malaysia,Kelantan,Malaysia.The visual acuity and optic nerve function tests were performed by a single investigator.Likewise,Humphrey automated perimetry,optical coherence tomography (OCT) measurement of the retinal nerve fibre layer (RNFL) and pattern visual evoked potential (PVEP) were performed by a single technician.The examinations were performed before initiating ethambutol treatment and 3mo after that.RESULTS:There was no change in visual acuity,colour vision,light brightness,red saturation and fundus findings pre and post ethambutol.However,there was a statistically significant deterioration in the mean deviation of the visual field post treatment (P=0.010).There were also significant changes on OCT and PVEP,with increased RNFL thickness in all quadrants (P＜ 0.05) and PVEP delayed P100 peak latency and amplitude (P＜0.001).CONCLUSION:Ethambutol toxicity is a known complication of tuberculosis treatment.Early detection of this toxicity may prevent severe irreversible visual loss.The use of OCT to detect RNFL thickness and PVEP to assess P100 latency and amplitude can assist in the detection of subclinical anatomical and visual function changes prior to development of abnormalities on conventional optic nerve function tests.