Characteristics and Long-term Follow-up of Isolated Vertical Nystagmus in Infancy

Purpose: To determine the clinical characteristics and long-term outcomes of infants who presented with isolated vertical nystagmus. Methods: The medical records of 114 infants who were diagnosed as having nystagmus from 1996 to 2016 were screened. Patients with vertical nystagmus within the first year of life who had unremarkable magnetic resonance imaging of the brain and demonstrated age-appropriate visual behavior were included. The parents of patients in the final study cohort were contacted by telephone to obtain long-term follow-up information. Results: Eight patients comprised the final cohort. Vertical nystagmus was first observed at a mean age of 1.4 months (range: 1 to 2.5 months) and resolved in 87.5% of patients at a mean age of 3.8 months (range: 2 to 10 months). Vertical nystagmus was intermittent in 62.5%, upbeat in 62.5%, and pendular in 37.5% of patients. One patient's nystagmus did not resolve. Seventy-five percent of patient guardians participated in the telephone questionnaire. The mean age of patients at follow-up was 3.5 years (range: 0.5 to 8.1 years). Isolated iris transillumination was discovered in one patient without other features of albinism. Fifty percent of patients had speech delay requiring intervention. No other developmental delays or general medical conditions were identified. Conclusions: Nystagmus resolved in 87.5% of patients, all before the first year of life, and speech delay was later identified in half of the patients.