Abstract：
OBJECTIVE: To screen patients on ethambutol and evaluate its role on visual functions and toxic optic neuropathy.
METHODS: Retrospective, observational single tertiary centre cohort of 80 patients.
METHODS: A total of 69 from the initial 80 patients with visual complaints were categorised into two groups A and B; ongoing anti-tubercular therapy with ethambutol and having stopped ethambutol for greater than six months respectively. All patients underwent vision (V) testing on ETDRS chart and anterior and posterior segment evaluation. Additionally, patients in group A recorded color vision (CV) on Ishihara chart and visual evoked potential (VEP).
METHODS: P value was calculated using Chi square test (SPSS ver. 20).
RESULTS: Out of 69 patients in our study, 58 (84.05%) patients recorded reduced visual acuity. The mean visual acuity was 0.58 logMAR units. 33 out of our 58 (57%) patients with reduced visual acuity showed normal optic discs while 25 out of 58 (43%) showed altered optic discs. In group B, 14 out of 32 patients with vision of less than 20/20 also had optic disc pallor (p = 0.02). 12 out of 15 patients in group A recorded an altered color vision and also had a vision of less than 20/20 (p = 0.023). 15 patients who recorded altered VEP also had vision of less than 20/20 (p = 0.037).
CONCLUSIONS: Visual acuity, color vision and vep are sensitive and sustainable tools which can be implemented in regular screening. Ethambutol toxicity is a real problem and a collaborative approach is necessary to establish screening protocols and prevent ethambutol induced toxic optic neuropathy.
METHODS: Retrospective, observational single tertiary centre cohort of 80 patients.
METHODS: A total of 69 from the initial 80 patients with visual complaints were categorised into two groups A and B; ongoing anti-tubercular therapy with ethambutol and having stopped ethambutol for greater than six months respectively. All patients underwent vision (V) testing on ETDRS chart and anterior and posterior segment evaluation. Additionally, patients in group A recorded color vision (CV) on Ishihara chart and visual evoked potential (VEP).
METHODS: P value was calculated using Chi square test (SPSS ver. 20).
RESULTS: Out of 69 patients in our study, 58 (84.05%) patients recorded reduced visual acuity. The mean visual acuity was 0.58 logMAR units. 33 out of our 58 (57%) patients with reduced visual acuity showed normal optic discs while 25 out of 58 (43%) showed altered optic discs. In group B, 14 out of 32 patients with vision of less than 20/20 also had optic disc pallor (p = 0.02). 12 out of 15 patients in group A recorded an altered color vision and also had a vision of less than 20/20 (p = 0.023). 15 patients who recorded altered VEP also had vision of less than 20/20 (p = 0.037).
CONCLUSIONS: Visual acuity, color vision and vep are sensitive and sustainable tools which can be implemented in regular screening. Ethambutol toxicity is a real problem and a collaborative approach is necessary to establish screening protocols and prevent ethambutol induced toxic optic neuropathy.
摘要：
目的：筛选服用乙胺丁醇的患者，并评估其在视觉功能和中毒性视神经病变中的作用。
方法：回顾性，80例患者的单三级中心队列观察。
方法：将最初的80例视觉不适患者中的69例分为A组和B两组；分别使用乙胺丁醇进行抗结核治疗和停用乙胺丁醇超过六个月。所有患者均在ETDRS图上进行视力（V）测试以及前后段评估。此外,A组患者在石原表上记录色觉（CV）和视觉诱发电位（VEP）。
方法：使用卡方检验计算P值（SPSSver。20).
结果：在我们研究的69名患者中，58例(84.05%)患者记录视力下降。平均视力为0.58logMAR单位。我们的58例（57％）视力下降的患者中有33例显示正常的视盘，而58例中有25例（43％）显示视盘改变。B组,32例视力低于20/20的患者中，有14例也有视盘苍白（p=0.02）。A组15名患者中有12名记录了色觉改变，并且视力小于20/20（p=0.023）。15例记录VEP改变的患者的视力也低于20/20（p=0.037）。
结论：视力，彩色视觉和vep是敏感和可持续的工具，可以在定期筛查中实施。乙胺丁醇毒性是一个真正的问题，必须采取协作方法来建立筛选方案并预防乙胺丁醇引起的中毒性视神经病变。
方法：回顾性，80例患者的单三级中心队列观察。
方法：将最初的80例视觉不适患者中的69例分为A组和B两组；分别使用乙胺丁醇进行抗结核治疗和停用乙胺丁醇超过六个月。所有患者均在ETDRS图上进行视力（V）测试以及前后段评估。此外,A组患者在石原表上记录色觉（CV）和视觉诱发电位（VEP）。
方法：使用卡方检验计算P值（SPSSver。20).
结果：在我们研究的69名患者中，58例(84.05%)患者记录视力下降。平均视力为0.58logMAR单位。我们的58例（57％）视力下降的患者中有33例显示正常的视盘，而58例中有25例（43％）显示视盘改变。B组,32例视力低于20/20的患者中，有14例也有视盘苍白（p=0.02）。A组15名患者中有12名记录了色觉改变，并且视力小于20/20（p=0.023）。15例记录VEP改变的患者的视力也低于20/20（p=0.037）。
结论：视力，彩色视觉和vep是敏感和可持续的工具，可以在定期筛查中实施。乙胺丁醇毒性是一个真正的问题，必须采取协作方法来建立筛选方案并预防乙胺丁醇引起的中毒性视神经病变。
