Abstract
Purpose
To evaluate the repeatability of the corneal biomechanical measurements obtained by
Corvis ST in post-orthokeratology patients and analyze the correlation between the
biomechanical and ocular parameters.
Methods
Fifty-one eyes of 51 myopic subjects were included in this study. The biomechanical
parameters were assessed using Corvis ST. Repeatability was assessed using one-way
ANOVA based on within-subject standard deviation (Sw), repeatability coefficient (RC),
intraclass correlation coefficient (ICC) and correlation of variation (CoV). The correlation
was evaluated using Pearson correlation analysis.
Results
All parameters measured by Corvis ST, except length of flattened cornea at the first
and second applanations (A1L and A2L), showed a good intraobserver repeatability after
a 3-month follow-up period. The ICC values for A1L and A2L were 0.444 and 0.654, whereas
the other parameters were higher than 0.8. Similar trends were obtained for CoV, wherein
the CoV values for A1L and A2L were greater than 13 %. The corneal biomechanical parameters
were correlated with age, refraction, axial length (AL), steep and flat keratometry
before and after orthokeratology, and central corneal thickness (CCT). Following orthokeratology
treatment, post-keratometry demonstrated a higher correlation with stiffness parameter
at first applanation (SP-A1), velocity of corneal apex at the first applanation (A1V),
and radius than pre-keratometry, which showed a weak correlation with SP-A1.
Conclusion
Corneal biomechanical parameters assessed using Corvis ST demonstrated a good repeatability,
except A1L and A2L. The corneal biomechanical parameters were correlated with age,
refraction, AL and pre- and post-keratometry. Thus, Corvis ST is a suitable device
for investigating biomechanical parameter.
Keywords
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Article info
Publication history
Published online: December 09, 2022
Accepted:
December 4,
2022
Received in revised form:
December 2,
2022
Received:
August 3,
2022
Publication stage
In Press Corrected ProofIdentification
Copyright
© 2022 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
