Full-Field Electroretinography (ffERG)

What does it measure?

ffergThe ffERG measures widespread alteration of the functional integrity of the outer layer of the retina including photoreceptors and bipolar cells.  The ffERG is not sensitive to selective loss of the retinal ganglion cell layer, optic nerve or local retinal lesions. The ffERG is altered by drugs, diseases, ischemia, or procedures that diffusely affect cellular functions.

How is it measured?  

fferg scotopic2Small contact lens electrodes are placed on the cornea; the retina is stimulated by light delivered within a sphere, or Ganzfeld; and the electrical potentials generated by photoreceptors and bipolar cells are recorded.   A standard ERG measures five retinal responses by isolating rod (scotopic) and cone (photopic) circuits following dark and light adaptation.

Why is it important?  

ffERG testing can accelerate drug development. Ocular compounds move more quickly through the FDA approval process if preclinical electrophysiologic data demonstrate no negative effects. OSOD can develop specialized ffERG protocols to meet specific species or development goals.