Eccentricity Dependency of Retinal Electrophysiological Deficits in People With Episodic Migraine.

PURPOSE

During the non-attack period, people with migraine may show retinal dysfunction. This study builds on previous work by exploring the possibility of foveal and non-foveal visual field and electroretinographic deficits and determining the overlap in eccentricity of such localized visual deficits in people with migraine.

METHODS

Visual fields and multifocal electroretinography (mf-ERG) were tested in 27 people with migraine (aged 19-45 years) and 18 non-headache controls (aged 20-46 years). Data were averaged according to 5 concentric rings at 0.05). In contrast, the non-foveal mf-ERG was reduced in amplitude in people with migraine relative to controls (P < 0.001), and this group difference depended on eccentricity (P < 0.001) - most prominently, in the parafoveal region (ring 2, P = 0.001).

CONCLUSIONS

Retinal electrophysiological deficits were observed in people with migraine in the parafoveal region (between 1.5 degrees and 5 degrees eccentricity), without corresponding visual field deficits. This suggests a spatially localized area of retinal neuronal dysfunction in people with migraine that is insufficient to manifest as a visual field sensitivity loss using standard perimetric methods. Our study highlights the added confound of migraine when conducting standard clinical retinal electrophysiological tests for conditions such as glaucoma, particularly non-foveally.