Purchase this article with an account.
Jason Ki-kit Lau, Sin-Wan Cheung, Michael J Collins, Pauline Cho; Short-term changes in choroidal thickness and axial length in children fitted with orthokeratology lenses of different compression factors. Invest. Ophthalmol. Vis. Sci. 2018;59(9):1786. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the influence of compression factor (CF) upon short-term changes in choroidal thickness (ChT) and axial length (AL) in young myopic children treated with orthokeratology (OK) and to examine the relationship between the magnitude of change in AL and ChT.
This was a within-subject, contralateral, double-masked clinical trial. OK lenses with different CFs (0.75 and 1.75 D) were fitted to the contralateral eyes of each subject in a randomized manner. AL (Lenstar) and ChT (Spectralis OCT) measurements were obtained prior to commencing OK lens wear and then weekly for one month. OCT images were segmented using customized software to determine the subfoveal ChT (with manual correction where appropriate). A repeated measures ANOVA was used to examine AL and ChT changes over time and between fellow eyes. Pearson correlation test was used to examine the correlation between the change in ChT and AL.
Twenty-five children (mean age: 9.3 ± 1.0 years) with low myopia (-2.12 ± 1.00 D) and minimal astigmatism (-0.37 ± 0.37 D) and anisometropia (0.04 ± 0.61 D) completed the study. Baseline refraction (-2.30 ± 1.05 D), ChT (253.3 ± 56.4 µm) and AL (24.30 ± 0.64 mm) were well-matched between the fellow eyes.There was no significant effect of CF upon ChT or AL (both p > 0.05). However, ChT and AL significantly changed over time (p < 0.005) in a quadratic trend of approximate anti-phase relationship (p < 0.001). ChT initially increased by 11.5 ± 12.1 µm at week 1 (p = 0.001) and gradually returned to its original thickness at week 4 while AL significantly decreased by 26.8 ± 6.9 µm at week 1 (p = 0.008) and returned to its original thickness at week 4. For both CFs, changes in ChT were only significantly correlated to changes in AL at week 3 (-0.56 < r < -0.41, p < 0.05).
Increasing the CF of OK lenses did not result in different changes in ChT and AL and the shortening of AL observed in OK treated children could not be entirely explained by an increase in ChT.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only