![Sample our Medicine, Dentistry, Nursing & Allied Health journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5944/TOC-Subject-Sample-2021-Medicine-Dentistry-Nursing-Allied-Health.jpg"})
Abstract
Background
To determine four‐year changes of corneal biomechanical parameters in Iranian children aged seven to eleven years and their correlation with optical components.
Methods
In this four‐year prospective cohort study, 468 children aged seven to eleven years who were initially evaluated in 2012 were re‐evaluated in 2016–2017. Multi‐stage stratified cluster sampling was applied. Cycloplegic refraction, biometry using LENSTAR/BioGraph, and corneal biomechanical assessment using Ocular Response Analyzer (ORA) were undertaken for each participant. The corneal biomechanical parameters assessed were corneal hysteresis (CH), corneal resistance factor (CRF), areas under the peaks 1 and 2 (p1 and p2 areas) and irregularity indices (A and B indices).
Results
All biomechanical parameters except A index decreased in phase 2. The mean changes of CH and CRF were 0.68 ± 0.16-mmHg (for both parameters) during four years. The mean difference in CH and CRF was 0.23 ± 0.23 and 0.24 ± 0.23-mmHg in females and 1.03 ± 0.23 and 0.96 ± 0.23-mmHg in males, respectively. Different age groups showed varying amounts of decrease in all parameters except for A index. The age group ‘ten years’ experienced the smallest decrease in CH (0.02 ± 0.48-mmHg) and CRF (0.20 ± 0.47-mmHg) and the age group ‘eleven years’ showed the greatest decrease in CH (1.41 ± 0.35-mmHg) and CRF (0.99 ± 0.34-mmHg). According to linear regression analysis, CH and CRF had a significant direct relationship with corneal power and an inverse relationship with axial length (p < 0.001).
Conclusion
Age and sex are influencing factors on the ORA parameters. Older age is associated with reduced biomechanical parameters and reductions are more significant in males than females. Axial elongation and corneal flattening decrease CH and CRF.
ACKNOWLEDGEMENTS
The authors would like to thank the participants who made this study possible. This research was supported by the Deputy of Research of Mashhad University of Medical Sciences (grant code: 950370) and Noor Research Center for Ophthalmic Epidemiology.