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S-Cone ERG

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S-Cone ERG

Posted on Friday April 1, 2022

The short-wavelength cone (S-Cone) protocol tests the blue-light receptor retinal pathway. This test can be useful for diagnosing inherited retinal disorders and distinguishing between rod monochromacy and S-cone monochromacy.  


The S-Cone protocol can be run on a ColorDome stimulator that delivers flashes of blue light on an amber-colored background. The background light serves to saturate the rod system and reduce contributions from the L- and M-cone systems.  


This test result forms two peaks, one for L- and M-cone response, and a second peak for S-cone response. 


Example Test

A normal S-Cone response following the L/M, long and medium cone responses.

S-Cone ERG



Perlman, I., Kondo, M., Chelva, E. et al. ISCEV extended protocol for the S-cone ERG. Doc Ophthalmol 140, 95–101 (2020). https://doi.org/10.1007/s10633-019-09730-6