Global visual field involvement in acute unilateral optic neuritis

PURPOSE: To quantify automated visual field defects seen at entry in the Op tic Neuritis Treatment Trial (ONTT) to determine whether particular areas o f the field are preferentially affected and to determine the extent of visu al field involvement in patients having "localized" field defects. METHODS: Review of Humphrey 30-2 Visual Field (Allergan-Humphrey, Inc, San Leandro, CA) data from the involved and fellow eyes of 440 patients who wer e enrolled in the ONTT. Field defects were evaluated by comparing the invol ved eye to the fellow eye. RESULTS: Patients with diffuse visual field defects had a relatively equal diminution of visual threshold throughout the tested 30-2 field. Patients w ith localized central and cecocentral scotomas had their greatest depressio n of threshold centrally; however, even those patients with mild defects (m ean defect, <6 dB) had diminution of visual threshold throughout the entire tested 30-degree field. Patients with moderate (mean defect, 6 to 20 dB) a nd severe (mean defect, >20 dB) central and cecocentral defects had even gr eater peripheral depression. Patients with altitudinal or quadrant defects had involvement of the "unaffected" field that also varied with the mean de fect. The overall average depression of visual threshold for all patients a veraged 36% +/- 4% and was relatively uniform throughout the tested field, CONCLUSIONS: Optic neuritis affects the entire central 30-2 field, even in patients who appear to have localized depression of visual threshold. Optic neuritis does not appear to have a predilection for any particular area of the visual field. (C) 1999 by Elsevier Science Inc. All rights reserved.