Acute unilateral papillitis versus retrobulbar neuritis: relation to multiple sclerosis

Prospectively referred patients with unilateral acute optic neuritis (ON) (n = 223; aged 12-57; 158 women), either idiopathic or part of clinically definite multiple sclerosis (CDMS), were systematically examined by the same physician. We analysed whether the 161 patients with retrobulbar neuritis and the 62 patients with papillitis differed from each other clinically or according to paraclinical tests. The following characteristics were observed in retrobulbar ON respectively papillitis: median age 33 and 33 years, women 70% and 73%, clinically definite MS 30% and 27%. Abnormal results in retrobulbar ON and in papillitis (indicated in brackets) did not differ significantly and were found as follows: cerebral MRI in 56% (63%), VEP from the eye with acute ON in 82% (88%), VEP from the eye without acute ON in 38% (33%), SEP from median nerves in 9% (10%), SEP from tibial nerves in 22% (22%) and biotesiometry in 32% (27%). In the CSF, oligoclonal bands were present in 42% (53%), increased IgG-index in 40% (44%) and increased leucocyte count in 39% (29%). The HLA-DRI5 tissue type was present in 47% (43%). There were no significant differences between retrobulbar ON and papillitis when the idiopathic cases and cases with clinically definite MS were analysed separately. Our data document that unilateral retrobulbar ON and papillitis are both part of the MS spectrum and not different from each other with regard to clinical and paraclinical parameters, indicating that the two groups can be pooled in future treatment trials.