Ocular findings in twelve patients of subacute myelo-optico neuropathy (SMON) thirty years after the onset

A massive outbreak of subacute myelo-optico-neuropathy (SMON) occurred in 1965 in Ibara and Yubara districts of Okayama Prefecture. Out of 287 members of Okayama-Ibara SMON Patients' Association, 12 patients underwent ophthalmological examinations in 1995. The tests included visual acuity, visual field, slitlamp biomicroscopy, funduscopy, color vision and critical flicker frequency. Six patients showed temporal pallor of the optic disc, central scotoma and concentric contraction attributable to SMON. In general, the patients showed low-grade visual disturbance. This feature could be explained by a biased selection of patients in this study. Ophthalmologists should be aware that many patients are still suffering from visual disturbances caused by SMON.