Study of Stimulus Parameters in Flicker Electroretinogram (ERG)

The electroretinogram (ERG) is a diagnostic test that measures the electrical activity generated by cells in the retina in response to a light stimulus. Typically, an ERG is recorded with white flash when the pupil is dilated. RETeval Visual Diagnostic Device (RETeval) generates an array of color flashes, which allows studying whether color flash would be a useful diagnostic tool. Full pupil dilation is required to obtain a response from the whole retina. However, this requirement often limits a patient's flow in the clinic and increases the overall time patients spend at the eye practitioner. RETeval provides the possibility of recording ERGs in un-dilated pupils therefore making the whole exam easier and shorter. These results need to be compared to the classic, fully dilated ERG and evaluated for efficiency. The purpose of this research study is to use the RETeval device to measure the eye's electrical response and how it changes with different stimuli such as changing flash color or pupil dilation.

Compare implicit times and amplitudes of electroretinograms obtained from series of color flashes to those obtained from white flashes.

Compare implicit times and amplitudes of ERGs obtained from cd/m2/sec stimulation (used with dilated pupils) to those obtained from troland stimulation (used with un-dilated pupils).

Flicker ERGs obtained to 56 CIE 1931 (created by the International Commission on Illumination (CIE) in 1931) colors series. White flash of 0,33, 0,33 was used for comparison.

Two series of white flashes: 3,0 cd/m2/sec and Trolands equivalent assuming 3,7 mm pupil size, delivered at 3 min interval over 30 min.

Inclusion Criteria: healthy adult volunteers volunteers able to get their pupil fully dilated Exclusion Criteria: pregnant women children subjects with light sensitivity photosensitive epilepsy allergies or sensitivity to pupil dilation ophthalmic solutions history of glaucoma cardiac dysrhythmia will not be invited to participate in this study. Pregnancy status, light sensitivity and photosensitive epilepsy will be based on volunteer's providing this information at the time of signing the consent form

Davis CQ, Kraszewska O, Manning C. Constant luminance (cd.s/m2) versus constant retinal illuminance (Td.s) stimulation in flicker ERGs. Doc Ophthalmol. 2017 Apr;134(2):75-87. doi: 10.1007/s10633-017-9572-3. Epub 2017 Feb 3.