Dear Editor,We read with interest the article titled “Analysis of regular screening of children in schools for the blind - Its importance” by Kavitha and Heralgi.[1] The authors have highlighted the importance of regular screening of children in blind schools to identify children with blindness due to treatable conditions. We appreciate the authors’ efforts and research. We would like to highlight few points regarding pyridoxine-dependent epilepsy (PDE), which is known to cause strabismus and incomplete/delayed myelination, thereby resulting in avoidable blindness.Prematurity and its neurological sequelae, including seizures, should not stand against the likelihood of PDE as a possible diagnosis.[2] Chinta et al.[3] evaluated the etiology and clinical features of optic atrophy in 324 children (583 eyes) <16 years of age. Hypoxic-ischemic encephalopathy (HIE) was the most common cause of childhood optic atrophy (133 children) in this study. Twenty patients in the HIE group were preterm. Two patients had intracranial hemorrhage. Forty children had squint and defective vision. Our assumption is PDE should be considered as a differential diagnosis in this subset of children. Squint and incomplete/delayed myelination is a feature of PDE.[4] Our assumption is that PDE caused optic atrophy due to impaired myelination, resulting in defective vision and strabismus. PDE may be misdiagnosed as HIE.[5] To conclude, PDE (treatable inborn error of metabolism) should be considered in children with neurological sequelae of presumed HIE, strabismus, optic atrophy, and defective vision.
Authors: Clara D M van Karnebeek; Sylvia A Tiebout; Jikkemien Niermeijer; Bwee Tien Poll-The; Aisha Ghani; Curtis R Coughlin; Johan L K Van Hove; Jost Wigand Richter; Hans Juergen Christen; Renata Gallagher; Hans Hartmann; Sylvia Stockler-Ipsiroglu Journal: Pediatr Neurol Date: 2016-01-11 Impact factor: 3.372