Variation in visual field measurements with an automated perimeter

Area of Science:

• Ophthalmology
• Visual Science
• Medical Technology

Background:

• Automated perimetry is a key tool for assessing visual field defects.
• Understanding the reliability and variability of these tests is crucial for accurate diagnosis.

Purpose of the Study:

• To evaluate the test-retest variability of automated perimetry in normal eyes.
• To determine if variations exceed clinically significant thresholds.

Main Methods:

• Visual field measurements were performed using the Octopus automated perimeter.
• Six subjects with normal eyes underwent testing on four separate occasions over four weeks.

Main Results:

• Eleven of twelve eyes exhibited at least one point with a light detection threshold variance greater than 4 dB between tests.
• This indicates substantial normal variation in visual field measurements.

Conclusions:

• Automated visual field results require cautious interpretation.
• Apparent pathologic changes may represent normal physiological variation, necessitating careful consideration of test-retest reliability.