Abstract
Purpose :
To investigate changes in choroidal thickness (ChT) and axial length (AL) in children with high myopia undergoing orthokeratology (OK), and their relationship.
Methods :
This prospective study randomly assigned subjects with high myopia in both eyes and <1.25D anisometropia to wear OK lenses with a conventional design targeted for 4.00D reduction (control group) or a dual reverse curve design targeted for full reduction (study group). Data from both eyes were collected at baseline and six-month intervals over one year and analyzed. Partial correlation analysis was used to examine the association between changes in AL and ChT, after controlling for age, gender, group, eye, baseline AL and ChT. Multivariate generalized estimating equation (GEE) analysis was used to investigate factors (age, gender, group, eye, baseline AL and ChT and changes in ChT) associated with axial elongation (AE) over one year.
Results :
Thirty-one Chinese children (18 control and 13 study) with a median age of 12 years and myopia of -5.75D completed the study. There were no significant differences in baseline myopia, AL, or ChT between the two groups. At the one-year visit, there was a mean±standard error reduction of 4.44±0.15D and 4.93±0.20D in myopia in the control and study groups, respectively (p=0.047). Over one year, no significant difference was found in changes in AL or ChT between the two groups. In all subjects, ChT and AL changed significantly over time. ChT thickened by 10±3µm in the first six months and remained stable in the second six months. AL decreased by 26±16µm in the first six months and increased significantly by 53±12µm in the second six months. Changes in ChT were significantly negatively correlated with AE at both the first and second six-month intervals. Multivariate GEE analysis showed that less AE was associated with older age and a greater increase in ChT in the first six months and was only associated with a greater increase in ChT in the second six months.
Conclusions :
The dual reverse curve OK lenses with a greater target showed comparable efficacy in slowing ocular growth in highly myopic children compared to the conventional design with a 4.00 D target. The one-year changes in AL and ChT indicated that ChT might play a role in slowing myopia progression in children with high myopia, especially in the first six months of treatment.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.