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USER MANUAL RETEVET™ PORTABLE ERG
T +49 7461 96 580 0 | F +49 7461 96 580 90 | export@eickemeyer.com | www.eickemeyer.com
Flash ERG Testing
For more complete retinal function testing (including issues of seeing in dim light situations), fl ash testing can be used in
addition to the fl icker testing.
1. Dark-adapted rod response (DA 0.01): provides information about rod system, night vision and therefore is useful in
detecting rhodopsin-related mutations and SARDS for example.
2. Dark-adapted, mixed, rod and cone response (DA 3.0): both, rod and cones are assessed. Photoreceptors are evaluated
separately (a-wave) from their pathways in the inner retina (b-wave) providing generalized yet complete evaluation of the
retinal function.
3. Dark-adapted mixed, rod and cone response to a higher intensity fl ash (DA 10.0): in addition to the information acquired
in the previous step, the response to the higher intensity fl ash allows for the evaluation of the impact the opacity of the
media such as a cataract has on the retinal function.
4. Dark-adapted Oscillatory Potentials (OPs) extracted from the mixed response by using the 85 – 190 Hz bandpass fi lter
provide more subtle and consistent information about the diffused changes in the inner retina caused by e.g., ischemic
events or amacrine cell function. These test results are mainly used for research purposes. Up to 5 cursors are automatically
placed on the oscillatory potential peaks and troughs and are indicated on the report as black dots on the waveform.
Implicit times (time to peak) and amplitudes (peak to following trough) are reported for each individual cursor. The sums
of implicit times and amplitudes for all cursors are also reported. When interpreting the summed cursor times and
amplitudes, you should examine the cursor dots on the waveform to ensure that no waves are missed.
5. Light adapted cone response (LA 3.0) provides an overall assessment of outer and inner retina in the day vision.
6. Light adapted fl icker (LA 3.0 fl icker) is a robust response of the cone pathway and an excellent tool for a quick assessment
of the retinal function.
Flash conditions in those steps depend on the species, particularly on their behavioral time of activity (nocturnal vs. diurnal).
Therefore, protocols are built based on the individual customer’s needs.
Subtests in these protocols display the waveform results after each measurement period and enable the operator to repeat
the step as many times as desired. Automated cursor placements are computed to the average cursor placement across all
repetitions. Any subtest can be skipped without affecting the rest of the protocol. On the review screen, the operator has the
option of selecting which replicates to keep from the reports. This option enables replicates to be deleted in the event, for
example, of poor patient compliance or excess noise in some replicates. To remove a replicate, simply uncheck the box
associated with that replicate. Replicates can be selected or removed anytime while collecting replicates. After you have
moved to the next test step, you no longer can alter the replicate selection for previous steps.
For dark-adapted tests, the display is automatically dimmed and reddened. The green power status LED is also turned off to
assist in dark-adaptation. The display and LED are automatically brightened at the end of the dark-adaptation tests.
To create the visual stimulus, the RETevet™ device generates variable-duration fl ashes of white light, made from red, green,
and blue LEDs all being on for the same duration. The maximum energy fl ash of white light is 30 cd·s/m², which has a fl ash
duration of 5 ms.
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