Abstract
Purpose: :
To compare the pattern of visual field loss obtained with static automated perimetry (SAP) to the pattern of increased latency of the multifocal visual evoked potential (mfVEP) in patients with recovered optic neuritis (ON).
Methods: :
20 eyes of 20 patients with ON, ranging in age from 25 to 54, who underwent both mfVEP and 24-2 SAP testing within a 2 month period, were identified retrospectively. Patients with an attack within 6 months of testing were excluded. All patients had a visual acuity of 20/25 or better. Pattern reversal mfVEPs were recorded in response to a 44° diameter, 60 sector dartboard pattern (VERIS, EDI) using a montage of 4 electrodes as previously described.[1] The latency of the responses for each sector was calculated with a computer algorithm and compared to control values.[2] The locations of abnormal (p<5%) mfVEP latencies were displayed on monocular and intraocular probability plots [2], which were combined to show all abnormal points. The number of abnormal points was tabulated at each location. The number of abnormal (p<5%) points at each location was likewise tabulated for the total deviation SAP plot.
Results: :
There were a significantly higher percentage of abnormal points on the mfVEP latency plots than on the SAP visual fields. 48.0% of the sectors of the mfVEP had abnormally long latencies, while 20.1% of the visual field locations on SAP were abnormal. Further, only 25.0% of the patients had abnormal mean deviations on SAP, while 95% of patients had significant mean mfVEP delays.[3] The most common locations of increased latency in the mfVEP were in the cecocentral and inferior arcuate regions. For the SAP fields, there were an insufficient number of abnormal points to confidently determine a pattern.
Keywords: neuro-ophthalmology: optic nerve • electrophysiology: clinical • visual fields