Inter- and intraindividual sensitivity variations with manual and automated static perimeters

Area of Science:

• Ophthalmology
• Visual Neuroscience
• Medical Technology

Background:

• Accurate measurement of visual field sensitivity is crucial for diagnosing and monitoring various eye conditions.
• Automated perimetry devices are widely used, but their precision compared to manual methods requires ongoing evaluation.
• Understanding variability in visual field testing is essential for reliable clinical interpretation.

Purpose of the Study:

• To compare the precision of different perimetry devices in assessing monocular visual field increment sensitivities in normal subjects.
• To investigate the sources of variability (interindividual vs. intraindividual) in visual field testing.
• To evaluate the impact of visual field location (periphery, superior quadrant, blind spot) on measurement precision.

Main Methods:

• Monocular visual field increment sensitivities were measured in 10 normal subjects using Octopus, Humphrey, Perimat, and Tübingen perimeters.
• One subject was tested 10 times to assess intraindividual variability.
• Interindividual variability was assessed across the 10 different subjects.

Main Results:

• Interindividual spread in visual field sensitivity was greater than intraindividual spread.
• Variability increased towards the visual field periphery and in the superior quadrant.
• Automated perimetry generally showed greater spread than manual Tübingen perimetry, particularly near the blind spot.

Conclusions:

• Automated perimetry devices, in this experience, did not demonstrate superior precision to manual Tübingen perimetry in normal subjects.
• Variability in visual field testing is influenced by the subject, the testing device, and the location within the visual field.
• Further research may be needed to optimize automated perimetry protocols for enhanced precision.