Untitled

Abstract

Vitelliform macular dystrophy (VMD) is widely known for an abnormal EOG in the presence of a normal ERG. In this study the multifocal electroretinogram (MF-ERG) is described as an additional tool to detect retinal dysfunction in VMD. Three patients aged 30, 37 and 59 years with VMD and a visual acuity of OD: 0.4; OS 0.05 (patient 1), 1.25 OU (patient 2) and OU: 0.6 (patient 3) underwent additional electrophysiological testing with the MF-ERG. A multifocal-ERG of the central 50 degrees of the retina was obtained using the VERIS-system. During recording 103 hexagons flickered according to a binary m-sequence of 2(15). Mean luminance was 100 cd/m2, contrast was set at 99%. The MF-ERG recordings were compared to age matched control groups. In all three patients the MF-ERG of the central 6 degrees showed reduced amplitudes for N1P1 (first negative peak to first positive peak) and for P1N2 (P1 to the second negative peak). Implicit times were not affected. Therefore the MF-ERG can detect focal retinal dysfunction in VMD which would not be apparent in the summed retinal response recorded with the ganzfeld ERG. In contrast to other diseases, amplitudes rather than implicit times seem to be affected in the MF-ERG of vitelliform macular dystrophy.

Multifocal Oscillatory Potentials in the ‘Two Global Flash’ mfERG in High and Normal Tension Primary Open-Angle Glaucoma

“…In conclusion, our results support previous findings, that interposing bright global flashes into the stimulation sequence, increases the sensitivity of the mfERG to detect retinal dysfunction in glaucoma [15,16,27]. While the second induced component of a Figure 5 depicts the receiver operating characteristics (ROC) curves for the IC-2 of group average 7 for NTG patients (left) and POAG patients (right).…”

“…It is interesting to note that in the one global flash mfERG, not only do adaptive effects of the focal m-sequence stimulus influence the ICresponse, but the global flashes also influence the response to the focal flash [19]. This also holds true for stimuli with 3 global flashes, where the response to the focal flash is greatly altered [15]. These nonlinear contributions, have been reported to be much larger in the IC than in the DC.…”

“…Of the nonlinear contributions to the mfERG, the optic nerve head component (ONHC) which has been attributed to the nerve fiber layer [20][21][22][23] is reflected in a large naso-temporal asymmetry of the mfERG response that may be diminished in glaucoma [22,24]. Indeed, the IC has been shown to contain a large naso-temporal asymmetry, while this is only slightly present in the focal flash response [15,16,19]. These adaptive mechanisms are generally attributed to the inner retina [15,16], another reason to apply a global flash paradigm that elicits induced components to the diagnosis of glaucoma.…”

“…Indeed, the IC has been shown to contain a large naso-temporal asymmetry, while this is only slightly present in the focal flash response [15,16,19]. These adaptive mechanisms are generally attributed to the inner retina [15,16], another reason to apply a global flash paradigm that elicits induced components to the diagnosis of glaucoma.…”

Bestrophin 1 and retinal disease

“…In late stages, however, the photopic ERG can sometimes be slightly decreased. Additionally, the multifocal ERG is affected in stages two through four and this is to be expected given the morphological changes (Palmowski et al, 2003). Multifocal ERG readings therefore do not add any further information than what can be gleaned from fundus findings.…”