Ethambutol Optic Neuropathy

Paul D. Chamberlain; Ama Sadaka; Shauna Berry; Andrew G. Lee


Curr Opin Ophthalmol. 2017;28(6):545-551. 

In This Article

Ethambutol-induced Optic Neuropathy in Children

Interestingly, the prevalence of EON in children treated with ethambutol is much less than in adults. One review of the literature found the prevalence of vision loss from EON to be 0.05%, or 2 in 3 811 in children taking doses between 15 and 30 mg/kg per day,[68] and the two reported cases were not clear-cut EON.[69,70] In addition to an absence of clinical findings of EON in children, subclinical findings have also been seldom reported. In one study following 47 children on ethambutol therapy,[40] there were no differences in the latency of the p100 wave, a finding suggestive of subclinical toxicity in adults. For many years, ethambutol was used very cautiously in children of any age and its use was not recommended in children under the age of 5 because of their inability to describe changes in their vision.[68] However, these recommendations have recently changed. In 2010 the WHO raised the recommended dose of ethambutol for children to 20 mg/kg per day from the previous 14 mg/kg per day.[71] For some reason not completely understood, the serum concentration of ethambutol in children is lower than in adults for a given dose. As long as the WHO prescription guidelines are followed, the likelihood of EON in children is extremely small. Despite the low prevalence of EON in children, however, we still recommend that children taking ethambutol should be monitored.