Risk factors for developing multiple sclerosis after childhood optic neuritis.

We reviewed the records of all children (younger than 16 years of age) who presented with a diagnosis of optic neuritis (ON) identified through the comprehensive records-linkage system at the Mayo Clinic and identified 94 cases between 1950 and 1988 with a documented history of idiopathic ON. Detailed follow-up information was available on 79 patients, with a median length of follow-up of 19.4 years. Life-table analysis showed that 13% of the 79 patients with isolated ON had progressed to clinically or laboratory-supported definite multiple sclerosis (MS) by 10 years of follow-up, 19% by 20 years, 22% by 30 years, and 26% by 40 years. Gender, age, funduscopic findings, visual acuity, or family history of either ON or MS did not predict the development of MS. The presence of bilateral sequential or recurrent ON increased the risk of developing MS (p = 0.002; hazard ratio = 5.09), whereas the presence of infection within 2 weeks before the onset of ON decreased the risk of developing MS (p = 0.060; hazard ratio = 0.24). This study of childhood ON supports the lower risk of recurrence and progression to MS compared with adults.