FUNCTIONAL RETINAL GANGLION CELL ACTIVITY FOLLOWING LIGHT-INDUCED RETINAL DAMAGE IN MICE

Abstract

The scotopic threshold response (STR) of the electroretinogram (ERG) is thought to measure inner retinal function, specifically retinal ganglion cells (RGCs). However, the degree to which the STR is masked by the larger amplitudes of outer retinal function is not known. Light-induced retinal damage (LIRD) was used to selectively cause photoreceptor death in pigmented and albino mice to examine whether the effects of phototoxicity extend beyond photoreceptors. In pigmented mice, there was no structural loss measured with optical coherence tomography over a 121-day period, however, there was a decrease in ERG function. In albino mice, we found retinal thickness loss over a 73-day period, which correlated with the much larger decrease in outer retinal function. No RGC loss was observed with either strain. Changes in inner retinal function are much larger in albino compared to pigmented mice despite no structural loss, suggesting that there are other underlying mechanisms affecting the RGC function indirectly via the loss of photoreceptors, and thereby the generation of the STR.