Motion perimetry identifies nerve fiber bundlelike defects in ocular hypertension.

OBJECTIVE

To determine whether patients with ocular hypertension (OHT) have elevated motion perimetry thresholds.

DESIGN

Motion perimetry uses a customized computer graphics program to detect the ability to identify a coherent shift in position of 50% of dots in a defined circular area against a background of fixed dots. Motion size threshold is defined as the smallest circular area in which dot motion is detected. Subjects respond by touching the area of the computer monitor with a light pen where motion stimuli are perceived. Reaction times (milliseconds) to stimuli and localization error (number of pixels from target center) are also obtained for each trial.

SETTING

University hospital ophthalmology clinic.

PATIENTS OR OTHER

PARTICIPANTS

Twenty-seven patients with OHT and 27 age-matched normal subjects. One eye was tested in each subject.

MAIN OUTCOME MEASURES: Random dot motion stimuli size thresholds and total deviation probability plot data, reaction times, and spatial localization errors.

RESULTS

The patients with OHT had more abnormal test points in the total deviation probability plot analysis compared with the controls (P < .001, chi 2). The abnormal test points were concentrated in the superior and inferior nasal regions. Six subjects had nerve fiber bundlelike defects to motion stimuli. Six subjects (5 overlapping with the probability plot analysis) had abnormal glaucoma hemifield test results. The patients with OHT also had significantly greater localization errors.

CONCLUSION

Motion threshold perimetry may be a more sensitive method to detect visual field abnormalities in OHT than conventional automated perimetry.