Repeatability of Noninvasive Break-Up Time Measurements using Keratograph Oculus 3

Area of Science:

• Ophthalmology
• Optometry
• Tear Film Dynamics

Background:

• Non-invasive break-up time (NIBUT) is a crucial indicator of ocular surface health.
• Accurate and repeatable NIBUT measurements are essential for diagnosing and managing dry eye disease.
• Keratographs offer a non-invasive method for assessing tear film stability.

Purpose of the Study:

• To evaluate the repeatability of NIBUT measurements using a keratograph based on one, two, or three partial measurements.
• To recommend an optimal methodology for NIBUT determination in clinical practice.
• To verify that repeated NIBUT measurements do not influence the outcome.

Main Methods:

• Prospective study involving 38 healthy volunteers.
• NIBUT measurements were taken using an OCULUS 3 Keratograph.
• Repeatability was assessed using Bland-Altman analysis and repeatability coefficients for different measurement series (one, two, or three partial measurements).

Main Results:

• No statistically significant differences were found between partial or all six NIBUT measurements.
• Repeatability coefficients improved with more measurements: 15.0s (1 measurement), 12.1s (2 measurements), and 10.0s (3 measurements).
• Significantly better repeatability was observed in eyes with low NIBUT (<10s).

Conclusions:

• Determining NIBUT from three consecutive measurements significantly enhances repeatability.
• Repeated NIBUT measurements do not adversely affect the measured values.
• The methodology using three partial measurements on a keratograph is recommended for clinical practice.