Abstract
Our purpose was to explore S-cone ERG protocols for a commercial full-field hand-held stimulator that contains colored LEDs, and to see whether the test would be useful as a part of routine ERG testing. S-cone responses were elicited by blue flashes over a longer-wavelength background. With the standard stimulator containing blue (461 nm), green (513 nm) and red (652 nm) LEDs, we were unable to obtain satisfactory responses. Reproducible S-cone ERGs were obtained with a stimulator that had been custom-fitted with shorter-wavelength blue (440 nm) LEDs for stimulation, and orange (590 nm) LEDs for background adaptation. S-cone responses took only a few minutes to record, and the typical waveform showed a slow peak at 45-50 ms with amplitude 3-9 μV, but ranging from 0 μV to more than 10 μV. Larger waves appeared in a patient with enhanced S-cone syndrome. S-cone responses could also be obtained with an alternating blue-orange flicker protocol. We added the S-cone response to our regular ERG protocol for a number of months. Although most normal subjects and patients showed recognizable S-cone responses with this stimulator, the amplitudes were small and there was too much variability to make the technique effective for routine clinical testing. In general, the S-cone responses followed the standard cone ERG responses in disease.
Original language | English |
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Pages (from-to) | 101-107 |
Number of pages | 7 |
Journal | Documenta Ophthalmologica |
Volume | 109 |
Issue number | 1 |
DOIs | |
State | Published - 1 Jul 2004 |
Keywords
- Electroretinogram
- Enhanced S-cone syndrome
- Hand-held stimulator
- S-cone
ASJC Scopus subject areas
- Ophthalmology
- Sensory Systems
- Physiology (medical)