P50 and N95 are key waves in pattern ERG (PERG), reflecting retinal ganglion cell (RGC) function:
- P50: Early positive wave, mainly from RGCs and inner retinal layers. Reduced amplitude or delayed timing suggests ganglion cell dysfunction, common in early glaucoma or optic neuropathies.
- N95: Later negative wave, more specific to optic nerve health. A drop in N95 amplitude often signals optic nerve damage or axonal loss.
Both waves together help gauge severity and progression of optic nerve diseases. For example, in glaucoma, P50 might reduce first, then N95 drops as damage worsens.