Nystagmus in infancy: causes, characteristics and main tools for diagnosis

Nystagmus in infancy may occur as part of an ocular condition, a neurological disorder or be idiopathic. The objective of our study was to evaluate the main causes for nystagmus in infants aged 0-1 year, the accompanying clinical characteristics and the effectiveness of different diagnostic tests used for reaching definite diagnosis. A retrospective study was conducted on medical records of infants who were seen at a tertiary hospital between 2016 and 2021. Clinical data were obtained including age at presentation, presence of strabismus, refractive errors, auxiliary tests performed to reach diagnosis, and initial versus final diagnosis. This study included 147 infants. The most common ocular pathology causing nystagmus was albinism followed by inherited retinal diseases (IRDs). Main tests that helped reach diagnosis included clinical examination, genetic testing and electroretinogram (ERG). Vertical nystagmus was seen in 8/147 infants; among them 4 had an IRD as a final diagnosis. The most common associated clinical characteristics were high hypermetropia and strabismus. The most common causes for nystagmus during the first year of age were albinism and IRDs. The most useful diagnostic tests to reach diagnosis were ERG together with genetic testing for IRDs and clinical ophthalmologic examination for albinism. IRDs play an important role as the cause for nystagmus in infants; this diagnosis can be often missed during the first months of life and a vertical nystagmus wave is commonly observed in this group. Nystagmus secondary to a neurologic condition is rare in this age group.