Acute Optic Neuritis in Children : Clinical Features, Visual Outcome, Recurrence Rate, and Subsequent Evolution into Multiple Sclerosis

Koo, Nam Hyang; Kim, Yeun Hee; Kim, Sung Hwan

Abstract

PURPOSE: Acute optic neuritis is an inflammatory optic neuropathy, and rarely occurs in children. Childhood-onset optic neuritis is different from adult-onset optic neuritis in terms of clinical and prognostic aspects. We investigated the clinical characteristics and visual prognosis related to the steroid therapy in children with acute optic neuritis. In addition, we evaluated the recurrence rate of acute optic neuritis and subsequent evolution into multiple sclerosis.
METHODS
The medical records of ten children, who were previously admitted for acute optic neuritis at the Department of Pediatrics of Ajou University Medical Center from January 1995 to April 2004, were retrospectively reviewed. Nine patients were treated with intravenous methylprednisone pulse therapy, 0.5-1.0 g/day, for 3-5 days followed by an oral prednisone therapy. To 30 months after discharge, we followed up a long-term visual prognosis, recurrence rate and subsequent evolution into multiple sclerosis.
RESULTS
There were 4 boys and 6 girls and the mean age of onset was 10 years. Bilateral optic neuritis was noticed in 8 children and 9 children presented with papillitis. Etiology of acute optic neuritis was idiopathic in 50% of patients. Of the remaining cases, it was related with acute disseminated encephalomyelitis(30%), sinusitis(10%), and neuromyelitis optica(10%). Orbital MRI showed optic nerve enhancement and/or enlargement and optic disc protrusion in 15 of the 18 examined eyes. Visual evoked potential (VEP) was abnormal in 12 of the 16 examined eyes; P100 response was totally attenu ated in 6 eyes, and in the others the amplitude of P100 response was normal but the latency was delayed. On follow-up VEP at 1 month after steroid pulse therapy, the amplitude of P100 response was normalized in all, but the latency was still delayed in 60% of the patients. A short-term visual acuity after treatment with steroid was normally recovered in 14 of 15 involved eyes. Acute optic neuritis recurred in one of the nine patients who were treated with high dose methylprednisone pulse therapy, but there was no subsequent development of multiple sclerosis during the follow up.
CONCLUSION
The most common cause of acute optic neuritis in children is idiopathic, and presents as bilateral papillitis. On this study, a short-term visual prognosis after high dose methylprednisone pulse therapy is extremely good, but there was no significant difference in long-term visual prognosis at 6 months after treatment with steroid. Acute optic neuritis in children does not usually recur, and does not evolve into multiple sclerosis.