Diagnostic Testing

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Readalyzer

Readalyzer is a diagnostic tool that uses infared technology to record eye movements while reading. This is used to diagnose eye tracking and teaming dysfunctions as well as reading comprehension problems not remediated with tutoring.

Diopsys Nuero Optic Vision Assessment

The Diopsys Nuero Optic Vision Assessment (Visual Evoked Potential Testing Systems have been developed for eyecare professionals to objectively measure the neurological responses of the entire visual pathway. This test is non-invasive, patient friendly and olny takes a few minutes. Best of all, the patient is asked only to watch a series of quick videos to complete the test.

Visual Evoked Potentials

Visual Evoked Potentials (VEPs) are electrical signals that are measured from the electrophysiological activity (?brain waves?) at the visual cortex. A technician will generally place three sensors on the patient?shead to measure the VEP signal that travels from the retina to the visual cortex. VEPs occur when a patient observes a visual stimulus, such as a flash of light or a pattern on a monitor. VEP results are a representation of the functional integrity of all levels of the visual pathway including the retina, optic nerve, optic radiations, and visual cortex.

VEP waveforms are represented on graphs using amplitude and time (latency) measurements. In general terms, the amplitude, measured in microvolts (μv), indicates the integrity of the neural structures including axons conducting information along the visual pathway. Latency, measured in milliseconds (ms), indicates the time the electrical signal takes to travel from the retina to the visual cortex. The combination of amplitude and latency is helpful in determining the health of the visual pathway.

VEP recordings have been used for a variety of applications that involve neuro‐visual disorders such as glaucoma, amblyopia, multiple sclerosis, and diabetic retinopathy. Visual Evoked Potential tests provide the clinician with objective data on vision abnormalities that are often subtle and difficult to detect, as no response is required from the patient. This also allows clinicians to test preverbal children, infants, and patients with communication difficulties.