Method to detect transmissible spongiform encephalopathies via electroretinogram

A method for screening transmissible spongiform encephalopathy in livestock of the genus Bos via an electroretinogram, the method comprising:

• arranging electroretinogram electrodes on the eye of the livestock,
• producing and recording from said electrodes a biphasic electroretinogram waveform having an a-wave and b-wave from livestock retina in response to photic stimulus under photopic conditions,
• measuring the amplitude of the b-wave, wherein the amplitude is measured from the trough of the a-wave to the peak of the b-wave,
• measuring the implicit time of the b-wave, wherein the implicit time is measured from onset of photic stimulus to b-wave peak;
• and
• comparing said recorded waveform to a comparative waveform of livestock of the genus Bos known not to have transmissible spongiform encephalopathy,
• determining whether the recorded waveform has a decreased b-wave amplitude of approximately 20 percent to approximately 31 percent less than the comparative waveform or an increased b-wave implicit time of approximately 18 percent to approximately 23 percent greater than the comparative waveform, wherein a decreased b-wave amplitude or increased b-wave implicit time is indicative of the screened Bos livestock as having transmissible spongiform encephalopathy.

A method for screening transmissible spongiform encephalopathy in livestock of the genus Ovis via an electroretinogram, the method comprising:

• arranging electroretinogram electrodes on the eye of the livestock,
• producing and recording from said electrodes a biphasic electroretinogram waveform having an a-wave and b-wave from livestock retina in response to photic stimulus under scotopic conditions,
• measuring the amplitude of the b-wave, wherein the amplitude is measured from the trough of the a-wave to the peak of the b-wave,
• measuring the implicit time of the b-wave, wherein the implicit time is measured from onset of photic stimulus to b-wave peak,
• comparing said recorded waveform to a comparative waveform of livestock of the genus Ovis known not to have transmissible spongiform encephalopathy,
• determining whether the recorded waveform has a decreased b-wave amplitude of approximately 39 percent to approximately 54 percent less than the comparative waveform or an increased b-wave implicit time of approximately 89 percent greater than the comparative waveform, wherein a decreased b-wave amplitude or increased b-wave implicit time is being indicative of the screened Ovis livestock as having transmissible spongiform encephalopathy.