About

Test taker will see a series of 6 stimuli, each shown for 7 seconds, with a 3 second break before repeating the process. Look at the center point and fixate.

Testing Options: Right Eye/Left Eye/Both Eyes

What is the test? The RightEye test, similar to the Nidek MP1, shows six different targets of varying visual degrees to the test taker. Movement of the eyes via micro saccades and drifts are measured within one, two, four and greater than four degrees.

What is the purpose of the test? This test measures how stable the eye(s) remain(s) in fixed target locations over a short period of time.

Why is this important? Testing the neurological stability of fixation gaze given “fixation is an afferent and motor process: retinal sensory afferents produce efferent signals towards the extraocular muscles in order to maintain eye position. This can imply visual impairment, or eye diseases such as macular degeneration or scatoma.

The RightEye test reports fixation location and stability as well as grades for each variable, and has shown a high test-retest reliability compared to standard SLO measurements.

Life Example: An example of everyday use of fixation stability is reading.

Metrics

Fixation location (%): calculates the number  of x and y coordinates within 1 degree, 2 degrees and 4 degrees of the target.  Predominantly central (>50% of fixation points on the central 2 degrees), poor central fixation (<50% but >25%), predominantly eccentric (<25%).

Fixation Stability (%): calculates the number of x and y coordinates within 1 degree, 2 degrees, and 4 degrees of the target.  Stable (>75% within 2 degrees) relatively stable (<75% within 2 degrees but >75% within 4 degrees), unstable (<75% within 4 degrees).

BCEA (degrees squared): Bivariate Contour Ellipse Analysis. Due to the elliptical nature of fixation points, x and y coordinates are used to find an ellipse that fits the central set of x and y data points for left right and both eyes. Microsaccades and drifts of the human eye cause corrections of the eye back to a central point. These slight eye movements form an area of dispersion in the shape of an ellipse that is measured by the BCEA.