VISUAL-FIELD PROFILE OF OPTIC NEURITIS - ONE-YEAR FOLLOW-UP IN THE OPTIC NEURITIS TREATMENT TRIAL

Purpose: The purpose of this present study was to evaluate longitudina l visual field information for 448 patients over their first year of f ollow-up in the Optic Neuritis Treatment Trial. Methods: We reviewed 6 536 automated static visual fields performed on a visual field analyze r (Humphrey Visual Field Analyzer) at nine visits within the 1-year pe riod for each of the patients. Results: The median values of the mean deviations for affected eyes were as follows: -22.88 dB at baseline, - 1.94 dB at 6 months, and -1.62 dB at 1) ear. At 6 months, 51% of affec ted eye visual fields were normal, and at 1 year 55.9% were normal. Ap proximately two thirds (68.8%) of the fellow eyes were classified as a bnormal at baseline, although the defects were generally slight. One t hird (33.2%) were abnormal at 6 months, and approximately one third we re still abnormal at 1 year. More than 87% of those abnormal at 6 mont hs and at 1 year had been abnormal at baseline. Binocular analysis rev ealed that 13.2% of patients showed a chiasmal or retrochiasmal type o f field defect at least once during the year (5.1% bitemporal; 8.9% ho monymous). Of the patients who showed a retrochiasmal visual field def ect, 75.7% had an abnormal magnetic resonance imaging scan at baseline compared with 46% of the rest of the patients in the Optic Neuritis T reatment Trial (chi(2)=10.73, df=1, P<.002). Conclusion: Over the firs t year of follow-up, the majority of patients with visual field defect s from acute optic neuritis returned to normal, as measured by automat ed static perimetry. Many fields showed variation in the pattern and l ocation of the sensitivity loss. Chiasmal and retrochiasmal defects oc curred more commonly than previously reported.