Acute and subacute inflammation of the optic nerve and its sheath: clinical features in Chinese patients.

OBJECTIVE: Inflammation of the optic nerve (optic neuritis) and its sheath (optic perineuritis) can have similar initial clinical presentations. They are less well-defined in the Chinese than in Caucasians, and the aetiology of optic neuritis may also differ depending on ethnicity. The aim of our study was to document the clinical features of acute/subacute optic neuritis/optic perineuritis in Chinese patients. DESIGN: Retrospective case series. SETTING: Hong Kong Eye Hospital, Hospital Authority. PATIENTS: Records of all patients presenting to the Hong Kong Eye Hospital between 2005 and 2008, with their first episode of optic neuritis/optic perineuritis with onset of symptoms within 30 days, were reviewed. MAIN OUTCOME MEASURES: Disease aetiology, clinical features and outcomes. RESULTS: Twenty-nine patients were included (M:F=13:16), with a mean age of 46 years at presentation. Among these, 25 had optic neuritis and four had optic perineuritis; four presented with bilateral optic neuritis. Among the optic neuritis group, 17 (68%) were idiopathic, seven (28%) were related to multiple sclerosis, and one (4%) had neuromyelitis optica. Poor visual outcome in the optic neuritis group was associated with poor visual acuity at presentation and poor visual acuity at the nadir. CONCLUSION: Optic perineuritis and neuromyelitis optica-related optic neuritis were more commonly encountered in our study of Hong Kong Chinese patients than in Caucasian populations. Even in Chinese patients with 'typical' optic neuritis, neuro-imaging and further investigations may be warranted to exclude optic perineuritis/neuromyelitis optica, since Chinese ethnicity is itself an atypical feature. Where neuro-imaging is not readily available, intravenous methylprednisolone may be considered as initial treatment to cover both optic neuritis/optic perineuritis in patients with severe visual loss.