Variability of quantitative automated perimetry in normal observers

Area of Science:

• Ophthalmology
• Visual Science
• Medical Device Technology

Background:

• Automated static perimeters are crucial for diagnosing and monitoring visual field defects.
• Understanding test/retest variability is essential for reliable visual field assessment.

Purpose of the Study:

• To evaluate the test/retest variability of six commercial automated threshold static perimeters.
• To compare variability across different regions of the visual field.

Main Methods:

• Six commercially available automated static perimeters were tested.
• Three projection perimeters (Squid, Octopus 500, Humphrey Field analyzer) and three LED perimeters (Dicon 2000, Fieldmaster 50, Digilab 350) were used.
• Normal volunteers participated in the test/retest evaluations.

Main Results:

• All tested perimeters exhibited some degree of test/retest variability.
• Variability was found to increase from the central 10 degrees to 30 degrees of eccentricity for all devices.
• Some devices demonstrated better performance (lower variability) than others.

Conclusions:

• Despite advancements, all automated static perimeters have inherent test/retest variability.
• Increased variability in the mid-peripheral visual field (10-30 degrees) may affect diagnostic sensitivity.
• Clinicians should consider device-specific variability when interpreting visual field test results.