Inter-device variability of the Stratus optical coherence tomography

Area of Science:

• Ophthalmology
• Medical Imaging Technology

Background:

• Optical coherence tomography (OCT) is crucial for diagnosing and monitoring various eye conditions.
• Assessing inter-device variability is essential for reliable diagnostic test technology.
• The Stratus OCT is a widely used device for retinal imaging.

Purpose of the Study:

• To evaluate the measurement variability between different Stratus OCT devices.
• To determine the impact of signal strength on Stratus OCT measurements.
• To assess the clinical significance of inter-machine variability in OCT imaging.

Main Methods:

• Eight healthy subjects' eyes were scanned using four Stratus OCT machines across four medical centers.
• Fast retinal nerve fiber layer (RNFL) and macula protocols were employed.
• Inter-device variability, signal strength, and their correlation with thickness measurements were statistically analyzed using standard deviation, coefficient of variance, ICC, and Spearman correlation.

Main Results:

• No statistically significant differences were found for most macular parameters and all but one RNFL parameter across the four Stratus OCT machines.
• Mean signal strengths differed significantly between the Stratus OCT devices, with newer machines yielding stronger signals.
• Some RNFL parameters demonstrated a moderate, statistically significant correlation with signal strength.

Conclusions:

• While Stratus OCT machines showed minimal parameter variability, significant differences in signal strength were observed.
• Signal strength is a critical factor, correlating with some RNFL measurements and potentially influencing clinical assessments.
• Inter-machine variability in RNFL measurements and the inclusion of signal strength in assessments are clinically significant for patient follow-up and serial examinations.