The Photopic Negative Response as an Objective Measurement of Visual Function in Patients with Leber's Hereditary Optic Neuropathy (.pdf)

The photopic negative response (PhNR) is a slow negative component of a flash photopic full field ERG which has been shown to be specific for retinal ganglion cell (RGC) activity. Direct evaluation of RGC function is important in patients with Leber's Hereditary Optic Neuropathy (LHON) in which functional improvement with Idebenone and EPI-743 can take years to be clinically measurable, presumably due to the time required for CNS remodeling. Thus there is a need for objective non-invasive clinical metric in patients with LHON which does not rely on fixation and has the promise of directly measuring RGC activity. The purpose of this study was to evaluate the use of PhNR as a potential clinical metric for patients with LHON