[Clinical electroretinogram. Excerpt from a programmed instruction text].

PURPOSE: To describe multifocal electroretinography findings before and after laser photocoagulation of a subretinal nematode in diffuse unilateral subacute neuroretinitis. METHOD: Observational case report. A 45-year-old woman with left eye inflammation, subretinal tracts superior and temporal to the fovea, and a subretinal coiled mobile parasite was treated with laser photocoagulation to destroy the nematode. Multifocal electroretinography was performed before and after laser photocoagulation. RESULTS: In the left eye, multifocal electroretinography before treatment showed decreased foveal response density and increased parafoveal and perifoveal waveform amplitudes. Two months after laser photocoagulation, multifocal electroretinography showed full recovery of normal findings and the visual acuity remained 20/20. CONCLUSION: Multifocal electroretinography appears to be useful in evaluating the retinal findings after photocoagulation of a parasite associated with diffuse unilateral subacute neuroretinitis.

Electroretinography↗

PubMed2002

"On" response dysfunction in multifocal posterior pigment epitheliopathy.

PURPOSE: To determine the electroretinographic properties of one patient with multifocal posterior pigment epitheliopathy. METHODS: Rod and cone electroretinograms (ERGs) and photopic ERGs elicited by long-duration stimuli were studied in a patient with multifocal posterior pigment epitheliopathy. RESULTS: The amplitudes of both the rod and cone ERGs were significantly reduced. Photopic ERGs elicited by long-duration stimuli demonstrated that the b-wave ("on" response) was abolished but the d-wave ("off" response) was reduced by only amplitude. CONCLUSION: The ERG findings in multifocal posterior pigment epitheliopathy indicate that there is dysfunction not only of the photoreceptors but also in the signal transmission specific for the "on" pathway.

Electroretinography↗

PubMed2002

[The concept of induced components in multifocal electroretinograms].

PURPOSE: In the late period of a multifocal electroretinogram (mfERG) waveform, higher order-kernels copy themselves. These images are called projection components(or induced components), and contribute to the particular waveform of mfERG. I describe this feature, which the developer of the multifocal technique was fully aware of. METHOD: Inter-kernel comparisons were made of mfERGs, focusing on the characteristics and influence of induced components. RESULTS AND DISCUSSION: Even though induced components have never been described or discussed in detail in Japan, they are certainly one of the key elements in learning how the multifocal technique works and what the difference is between multifocal and conventional ERGs.

Electroretinography↗