electroretinogram

An electroretinogram, often abbreviated as ERG, is a diagnostic test used to measure the electrical response of the retina to light. It is performed by placing electrodes on or near the eye and then flashing a light stimulus. The electrodes detect the tiny electrical signals generated by the photoreceptor cells (rods and cones) and other retinal cells in response to the light. The ERG records these signals as waveforms, which can be analyzed by an ophthalmologist or optometrist.

The ERG is a valuable tool for diagnosing and monitoring a variety of retinal diseases and conditions. It can help identify abnormalities in retinal function that may not be apparent through a standard eye examination. For instance, it is commonly used to assess patients with suspected inherited retinal dystrophies, such as retinitis pigmentosa, or to evaluate the extent of damage from conditions like diabetic retinopathy or retinal artery occlusion.

Different types of ERG tests exist, including the full-field ERG, which assesses the overall retinal function, and the multifocal ERG, which provides more localized information about specific areas of the retina. The procedure is generally non-invasive and painless, although a topical anesthetic is often used to numb the eye. The results of an ERG test, when interpreted in conjunction with a patient's clinical history and other diagnostic findings, can provide crucial insights into the health and function of the retina.