Spatial cone activity distribution in diseases of the posterior pole determined by multifocal electroretinography

Abstract

Thirty patients with a reduced central vision due to diseases of the posterior pole were examined with the VERIS system developed by Sutter and Tran (Vis Res 1992;32:433-446) to characterize the topography of electroretinographic (ERG) changes in comparison to the results in 30 normal volunteers. Diagnoses included Stargardt's macular dystrophy (SMD, n = 10), age-related macular degeneration (AMD, n = 5), cone dystrophy (CD, n = 5), central retinal vein occlusion (CRVO, n = 5), and autosomal dominant optic atrophy (ADOA, n = 5). The 61 local responses obtained from each subjects were grouped by eccentricity to form five concentric rings. The foveal ERG, originating from a central area of 2 degrees radius, was non-recordable or markedly diminished in all patients except those with optic atrophy, where amplitudes were found to be in the normal range. In patients with advanced stages of SMD, functional defects were larger and involved more peripheral areas than in patients with early stages of SMD or with AMD. A reduction of response amplitude even in the most peripheral ring (17-30.5 degrees eccentricity) was found in cone dystrophies and--moderately--in patients with advanced SMD and central retinal vein occlusion only. Prolonged implicit times were found in all but the patients in early stages of SMD and they were maximal in patients with CRVO. This study shows that the multifocal ERG (MFERG) can contribute to differential diagnosis of retinal diseases of the posterior pole especially in cases with a normal photopic Ganzfeld ERG.

The Clinical Applications of Multifocal Electroretinography: A Systematic Review

“…167 The extent of mfERG changes is influenced by the severity of AMD as patients with neovascular AMD had more severe reductions in mfERG response amplitudes and delays in implicit times compared with patients with dry AMD. 110,152 Palmowski et al reported that the functional changes demonstrated by mfERG corresponded well with the anatomical changes detected on fluorescein angiography. 228 However, this was only based on the results from three AMD patients and subsequent studies have demonstrated that the mfERG abnormality tends to be more diffuse compared with the morphological changes.…”

“…14,54,56,57,72,91,110,122,151,152,167,172,228,248,258 Patients with early AMD were found to have significant reduction in the foveal P1 amplitude and delay in N1 implicit time compared with normal age-matched controls. 167 The extent of mfERG changes is influenced by the severity of AMD as patients with neovascular AMD had more severe reductions in mfERG response amplitudes and delays in implicit times compared with patients with dry AMD.…”

“…80,93,131,149,152,154,169,282 The main mfERG findings in patients with cone dystrophy include severe reductions in response amplitudes with delays in implicit times or complete absence of mfERG responses, especially in the central retina. 93,131,152,154,169,282 Holopigian et al evaluated both the cone-and rod-mediated mfERG in patients with cone dystrophy. 93 It was shown that patients had large reductions in cone-mediated mfERG amplitude and delays in implicit time which were more marked in the central retina.…”

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

“…Various studies have reported the efficacy of the mfERG in the assessment of ARMD [6,19,20,29,33,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58].…”

Ocular and Systemic Safety Evaluation of Calcium Formate as a Dietary Supplement

“…16,17 This test used the Visual Evoked Response Imaging System (version 4.9, EDI Inc., CA) with dilated pupils. Both eyes were tested simultaneously.…”