Figure 3: Scotopic and photopic ERGs from a normal 8-year-old ESS dog and two RPGRIP1−/− affected ESS dogs at the age of 9 (affected 1) and 12 years (affected 2), respectively. The latter affected dog was normal at ophthalmoscopic examination when it was 9 years old. At the age of 12 years it was only slightly visually compromised, and in a moderately advanced stage of retinal degeneration as seen by ophthalmoscopy. S5: scotopic ERG response using 10 mcd·s/m2 of light stimuli after 20 minutes of dark adaptation, Ssd: scotopic ERG response using 3 cd·s/m2 of light stimuli in the dark, Psd: photopic ERG response using 3 cd·s/m2 in the light after 10 minutes of light adaptation (with 30 cd/m2 of background light), Pfl: photopic ERG flicker response after 30 Hz flickering light stimuli in the light adapted state.