Clinical Analysis Of 64 Cases Of Idiopathic Optic Neuritis

Objective: To analysis initial clinical features of idiopathic optic neuritis in Guangxi area and short-term effect of corticosteroids on visual outcome.Methods: The medical records of all patients diagnosed as idiopathic neuritis optic admitted in the First Affiliated Hospital of Guangxi Medical University between 2003 and 2007 were retrospectively reviewed.Results: 64 cases (100 eyes), 23 men (35.9%), 41 women (64.1%) were included, with a mean age of 35.5±13.2 years. 36 cases (56%) were bilateral and 28 (44%) unilateral. Ocular pain was noted in 30 cases (47%), disc swelling showed in 36 cases (56%) and periventricular plaques in 3 cases (4.7%), while 3 cases (4.7%) met the criteria of multiple sclerosis (MS). There were no significant differences between our present study and Japanese study, but significant differences were found between ours and Optic Neuritis Treatment Trial (ONTT). Visual acuity was worse than 0.1 in 82 affected eyes (82%), varied from 0.1 to 0.5 in 17 eyes (17%), and 0.5 or better in 1 eye (1%). The patients in our study presented with more severe visual loss compared with ONTT patients (P<0.001) and with Japanese patients (P=0.011). Diffuse visual field defects were found in 57 eyes (57%). VEPs were abnormal in all cases (100%). FFA showed dye leakage at the optic disc in 36 cases (56%). CT revealed optic nerve thickening in 2 cases with a positive rate of 5.9%, and MRI revealed abnormal findings in optic nerves in 14 cases with a positive rate of 37%. 29 eyes were treated with intravenous methylprednisolone 0.5g, 28 eyes methylprednisolone 1.0g and 40 eyes dexamethasone 10～15mg. Visual acuity recovered faster in methylprednisolone 1.0g group than in dexamethasone group (P=0.046), but there was no significant difference between methylprednisolone 0.5g group and dexamethasone group (P=0.103).Conclusion: The idiopathic optic neuritis in Guangxi area showed its characteristics as that frequently affected bilateral optic nerve, low risk of developing MS and severe visual loss, and it was doubted as a forme fruste of neuromyelitis optica. Intravenous methylprednisolone 1.0g was a more effective treatment and was recommended by the authors.