Which test analyzes the health of the retinal pigment epithelium (RPE) by examining differences in electrical potentials between light and dark conditions?

The test that analyzes the health of the retinal pigment epithelium (RPE) by examining differences in electrical potentials between light and dark conditions is the Electrooculogram (EOG). This test measures the electrical potential difference between the front and back of the eye, which reflects the functionality of the RPE. During the EOG, patients are typically asked to follow a light stimulus, and the changes in electrical potential are recorded in both light and dark phases. The responses can indicate how well the RPE is working, which is crucial for proper phototransduction and overall retinal health. The amplitudes of the EOG responses can reveal dysfunctions in the RPE, helping in diagnosing conditions like Best disease and other retinal disorders associated with RPE issues.

Other options, while also related to eye health, serve different diagnostic purposes. The Electroretinogram (ERG) evaluates the overall function of the retina, including photoreceptors and inner retinal layers, but does not specifically focus on the RPE's health. Visual Field Testing assesses peripheral vision and can reveal defects related to a variety of conditions but does not provide information about the electrical activity of the RPE. Fundus Photography captures images of the retina but does not provide functional electrical