Cone-Mediated Multifocal Electroretinogram in Age-Related Macular Degeneration

Abstract

To evaluate the progression of change in the cone-driven multifocal electroretinogram (mfERG) responses in patients previously identified as having highrisk, soft drusen 63 µm or greater. Methods: Seventeen eyes of 14 patients were reevaluated after 28 to 41 months. Fundus changes were graded depending on drusen size and extent. Each of the 103 mfERG responses was analyzed and compared with agematched normal controls and with the baseline measurement. Results: Stable visual acuity was found in 12 of the 17 eyes. Drusen size or extent was increased, decreased, and unchanged in 6, 3, and 8 eyes, respectively. The mfERG responses demonstrated a significant progression in the response density loss and in N1 and P1 implicit time delay compared with the baseline evaluation regardless of drusen change. The extent of response deterioration occurred over the entire retinal area tested. Eyes having decreased drusen at follow-up were typically associated with higher response delays at baseline and follow-up than eyes with stable or increased drusen. Conclusions: Early age-related macular degeneration is associated with a progressive loss in the cone-driven mfERG response despite stable visual acuity. The response deterioration extended beyond the visible drusen area. Implicit times seem to be an important predictor of drusen regression.

Relationship between Retinal Layer Thickness and the Visual Field in Early Age-Related Macular Degeneration

“…40,41 At the mesopic background luminance of the MP-1 (1.27 cd/m 2 ) increment thresholds may be mediated by mixed rod-cone system responses, or by a mainly cone system response (Crossland MD, et al IOVS 2012;53:ARVO E-Abstract 4822). The nature of the response will also vary depending on damage due to retinal disease and intricate photoreceptor interactions.…”

Macular Function in Eyes with Open-Angle Glaucoma Evaluated by Multifocal Electroretinogram

“…19 Moreover, while FERG allows the electrophysiological evaluation of preganglionic elements in response to luminance stimuli presented in a restricted part of the central retina (4-9 retinal degrees), 1,2,20 the mfERG technique is useful for assessing responses of several different retinal areas enclosed between 18 and 208 of eccentricity from the fovea. [21][22][23] In fact, while the FERG recording collects the contribution from the entire macular region, mfERG ring analysis allows separating selective measures of bioelectrical responses obtained from localized macular areas. 22,23 This means that recording mfERG, testing visual acuity, and performing automated visual field analysis make it possible to explore the entire central retina and, through appropriate data analysis, to receive selective information regarding the function of localized retinal regions.…”

The electroretinogram: a useful tool for evaluating age-related macular disease?

“…Comparison between the conventional cone-mediated mfERG response and morphological changes in ARM have been examined [40,49,68], with outcomes suggesting slight increase in delayed implicit time with drusen progression, drusen regression with increasing RPE changes and in stable drusen. After more than 2 years, the responses became more delayed with reduced response density.…”