Application and repeatability of ocular biometric measures for gaze position calibration in children

• Published in: Ophthalmic & physiological optics 2021-09, Vol.41 (5), p.1144-1151
• Main Authors: Ntodie, Michael, Enimah, Eugene B, Akoto, Yaw O, Yennu, Joseph N, Abokyi, Samuel, Abu, Emmanuel K
• Format: Article
• Language: English
• Subjects: Adult; Anterior Chamber; Binocular vision; Biometrics; Biometry; Calibration; Child; Children; Cornea; gaze position; Hirschberg ratio; Humans; ocular biometry; Optics; Optics and Photonics; Pediatrics; Population studies; Reproducibility of Results
• ISSN: 0275-5408; 1475-1313
• DOI: 10.1111/opo.12866

Purpose The purpose of this study was to investigate the utility of two ocular biometric measurements to obtain Hirschberg ratios (HRs) in a binocularly normal paediatric population, and to assess the repeatability of this approach. Methods Ocular biometry data from 80 participants (aged 5 to 14 years) was obtained using the KM‐1 LED manual keratometer and the Tomey Biometer AL‐100 A‐scan. HRs were calculated from corneal curvature and anterior chamber depth measurements in the horizontal and vertical meridians of each eye using a regression equation based on a geometric optics model. To assess intrasubject variability in the HRs obtained from biometry, measurements were repeated approximately 1 h later. Results At the initial measurement, mean (SD, range) HRs were 10.77 (0.79, 9.14–12.73) and 11.02 (0.82, 9.48–13.32) °/mm for the horizontal and vertical meridians, respectively. There was a significant difference between the horizontal and vertical HRs (p