Does eye examination order for standard automated perimetry matter?

Area of Science:

• Ophthalmology
• Clinical Research

Background:

• Visual field (VF) testing is crucial for glaucoma diagnosis and monitoring.
• Fatigue during prolonged testing can potentially influence VF results, impacting diagnostic accuracy.

Purpose of the Study:

• To investigate the hypothesis that perimetric fatigue effects are more pronounced in the second eye examined during routine clinical visual field testing.
• To quantify the impact of fatigue on visual field outcomes in a large patient cohort.

Main Methods:

• Retrospective analysis of 6,901 patients' Humphrey Swedish Interactive Testing Algorithm (SITA) VFs from four glaucoma clinics.
• Comparison of Mean Deviation (MD) between the first and second tested eyes.
• Estimation of longitudinal MD variability using linear regression to assess fatigue effects.

Main Results:

• The second tested eye (typically the left) showed a statistically significant, albeit small, reduction in VF sensitivity (median 0.13 dB).
• A surrogate measure of longitudinal MD variability increased by a median of 3% in the second eye tested.
• No significant association was found between these fatigue effects and patient age or rest time between examinations.

Conclusions:

• Statistically significant perimetric fatigue effects are observable in the second eye during routine Humphrey Field Analyzer SITA examinations.
• The average magnitude of these fatigue effects is very small, with considerable inter-patient variability.
• Recommending initial examination of the right eye may help standardize results by ensuring any individual fatigue effects are consistent across visits.