CPT® Code 92270

Electro-oculography (EOG) is a specialized diagnostic test utilized to assess the functionality of the retinal pigment epithelium (RPE) within the eye. The RPE is a crucial layer of pigmented cells situated just outside the retina, positioned between the vascular choroid layer and the light-sensitive outer segments of the photoreceptors. This layer, along with the photoreceptors, plays an essential role in maintaining visual function by supporting the health and performance of the retina. The EOG procedure involves measuring the electrical potential changes across the RPE as the eye transitions between dark and light environments. During the test, the patient's pupils are dilated to enhance the accuracy of the readings. Electrodes are strategically placed on the skin, typically on the medial and lateral sides of the eye, to capture the electrical activity. The patient is then positioned in a head and chin rest within a full-field dome that features two red fixation lights, which are used to guide the patient's eye movements. The test consists of two phases: the dark phase and the light phase, each lasting 15 minutes. In the dark phase, the dome is set to complete darkness, and the fixation lights are alternately activated, prompting the patient to shift their gaze from one light to the other while recordings are taken. The light phase follows, where background lights are turned on, and the same alternating fixation light procedure is repeated. The EOG recordings are analyzed to evaluate the eye's adaptation to dark and light conditions, with specific parameters calculated to provide a comprehensive report of the findings, including the Arden ratio, dark trough amplitude, and light peak timing.