Periorbital Biometric Measurements using ImageJ Software: Standardisation of Technique and Assessment Of Intra- and Interobserver Variability.

Purpose: To assess the reliability and repeatability of periorbital biometric measurements using ImageJ software and to assess if the horizontal visible iris diameter (HVID) serves as a reliable scale for facial measurements.

Methods: This study was a prospective, single-blind, comparative study. Two clinicians performed 12 periorbital measurements on 100 standardised face photographs. Each individual's HVID was determined by Orbscan IIz and used as a scale for measurements using ImageJ software. All measurements were repeated using the 'average' HVID of the study population as a measurement scale. Intraclass correlation coefficient (ICC) and Pearson product-moment coefficient were used as statistical tests to analyse the data.

Results: The range of ICC for intra- and interobserver variability was 0.79-0.99 and 0.86-0.99, respectively. Test-retest reliability ranged from 0.66-1.0 to 0.77-0.98, respectively. When average HVID of the study population was used as scale, ICC ranged from 0.83 to 0.99, and the test-retest reliability ranged from 0.83 to 0.96 and the measurements correlated well with recordings done with individual Orbscan HVID measurements.

Conclusion: Periorbital biometric measurements using ImageJ software are reproducible and repeatable. Average HVID of the population as measured by Orbscan is a reliable scale for facial measurements.