Fluctuations on the Humphrey and Octopus perimeters

Area of Science:

• Ophthalmology
• Visual Neuroscience
• Medical Technology

Background:

• Accurate visual field testing is essential for diagnosing and monitoring eye conditions.
• Threshold determination in perimetry can be affected by short-term and long-term fluctuations.
• Automated perimeters like Octopus and Humphrey are widely used but may exhibit different reproducibility.

Purpose of the Study:

• To compare short- and long-term threshold fluctuation between the Octopus and Humphrey automated perimeters.
• To assess the impact of device differences on the reproducibility of visual field testing.

Main Methods:

• Thirty-six healthy subjects were recruited for the study.
• Visual field testing was performed using both Octopus and Humphrey perimeters with identical threshold programs.
• Each of the 16 tested locations was assessed twice to measure fluctuation.

Main Results:

• Short-term threshold fluctuation was significantly greater on the Octopus perimeter (1.6 +/- 0.3 dB) compared to the Humphrey perimeter (1.3 +/- 0.3 dB; P < 0.001).
• Heterogeneous long-term fluctuation was also higher on the Octopus perimeter (1.6 +/- 0.4 dB) versus the Humphrey perimeter (1.3 +/- 0.5 dB; P < 0.05).
• Homogeneous long-term fluctuation was minimal and comparable between both devices.

Conclusions:

• The Octopus perimeter demonstrated greater short- and long-term threshold fluctuation than the Humphrey perimeter.
• Differences in fluctuation between these automated perimeters can influence the evaluation of visual field abnormalities.
• Reproducibility in perimetry is influenced by various factors, including the specific device used.