Comparing multifocal pupillographic objective perimetry (mfPOP) and multifocal visual evoked potentials (mfVEP) in retinal diseases

Abstract

Multifocal pupillographic objective perimetry (mfPOP) shows regions of slight hypersensitivity away from retinal regions damaged by diabetes or age-related macular degeneration (AMD). This study examines if such results also appear in multifocal visual evoked potentials (mfVEPs) recorded on the same day in the same patients. The pupil control system receives input from the extra-striate cortex, so we also examined evidence for such input. We recruited subjects with early type 2 diabetes (T2D) with no retinopathy, and patients with unilateral exudative AMD. Population average responses of the diabetes patients, and the normal fellow eyes of AMD patients, showed multiple regions of significant hypersensitivity (p < 0.05) on both mfPOP and mfVEPs. For mfVEPs the occipital electrodes showed fewer hypersensitive regions than the surrounding electrodes. More advanced AMD showed regions of suppression becoming centrally concentrated in the exudative AMD areas. Thus, mfVEP electrodes biased towards extra-striate cortical responses (surround electrodes) appeared to show similar hypersensitive visual field locations to mfPOP in early stage diabetic and AMD damage. Our findings suggest that hypersensitive regions may be a potential biomarker for future development of AMD or non-proliferative diabetic retinopathy, and may be more informative than visual acuity which remains largely undisturbed during early disease.

Retinotopic effects of visual attention revealed by dichoptic multifocal pupillography

“…Overall, it seems we can at least partially choose cortical versus retinal sources by altering the temporal properties of the stimuli. This idea is supported by our demonstration that a visual field marker for early-stage macular degeneration and diabetic eye disease is seen both for yellow mfPOP and mfVEP testing on the same 47 patients when the mfVEP electrodes are positioned to pick up extrastriate cortical activity 32 . In summary, several sources of evidence indicate that mfPOP responses to transiently presented stimuli are substantially driven by the extrastriate cortex, as PON connectivity would suggest 30 .…”

Progresses and prospects of brain electromagnetic imaging

“…. 在认知神经科学的基础研究中, 基于脑电/ 磁成像的研究方法已用于听觉、视觉、语言、运动、 记忆、意识、情感、智力、学习等众多领域 以及视觉疾病的诊断 [142,143] , 同时也可用于评价疗效 和判断预后等.…”

Portable Objective Diagnostics using Visual Evoked Potentials for Age-related Macular Degeneration

“…Furthermore, the sensitivity of ERG to scotopic stimulus levels has been shown to be over 2 orders of magnitude worse than either VEP or psychophysical methods [35], so these tests do not serve well as functional measures of DAR. While there have been many studies of VEP in the context of DAR [36][37][35][38], and the use of multifocal VEP has been studied in the context of AMD [39][40][41], we believe that systematic use of this very attractive technique has been hampered by lack of easy-to-administer, affordable instrumentation, and we have not found any previous VEP studies of DAR in AMD, specifically, in the literature.…”