CPT® Code 92544

The optokinetic nystagmus (OKN) test, identified by CPT® Code 92544, is a specialized diagnostic procedure used to assess eye movement responses to visual stimuli. This test involves bidirectional stimulation, which means that the visual targets move in both rightward and leftward directions. The procedure utilizes foveal or peripheral stimulation, allowing for a comprehensive evaluation of the patient's eye movement capabilities. During the test, recording is conducted using electronystagmography (ENG), a technique that measures and records the electrical activity of the eye muscles. To perform the test, horizontal electrodes are strategically placed on the skin at the inner and outer aspects of each eye. As the patient observes a series of moving targets, which can include stripes on a rotating drum, a stream of lighted dots across a light bar, or a full-field array of moving stars or trees, their eye movements are recorded. The targets are moved at varying speeds, specifically at rates of 300, 400, or 600 feet per second, to elicit a response. The movement of the targets is then reversed, and the procedure is repeated, allowing for a thorough assessment of the eye's response to both directions of movement. The resulting eye movements generated during the test resemble nystagmus, a condition characterized by involuntary eye movement. After the test, the physician reviews the recorded data to evaluate the symmetry of the eye movement responses. An asymmetrical response may indicate potential central nervous system pathology, making this test a valuable tool in diagnosing various neurological conditions. Overall, the optokinetic nystagmus test is an essential procedure for understanding eye movement dynamics and identifying underlying health issues related to the central nervous system.