Effects of orthokeratology versus cylindrical annular refractive elements spectacle lenses on myopia control and choroidal thickness in myopic children: A 1-year prospective clinical trial.

Objective

To compare the 1-year effects of orthokeratology (OK) and cylindrical annular refractive elements (CARE) spectacle lenses on myopia control and choroidal thickness (ChT).

Methods

This prospective, non-randomized clinical trial recruited 504 children stratified into low (-2.75 to -1.00 D) and moderate (-5.00 to -3.00 D) myopia groups, and then were assigned to wear either OK, CARE (7-mm central zone surrounded by treatment zone incorporating CARE with mean positive power + 4.6 D), or CARE S (9-mm central zone surrounded by CARE with power + 3.8 D) lenses. The 1-year data were evaluated, including axial length (AL), spherical equivalent (SE), subfoveal (SF) ChT, and ChT in nine retinal regions.

Results

At the 1-year visit, there were no statistical differences in AL among the three groups in low myopia subjects (P > 0.05). For the moderate myopia subjects, the OK and CARE groups had lower AL elongation than the CARE S group (0.16 ± 0.12 mm and 0.19 ± 0.11 mm vs. 0.25 ± 0.15 mm, P < 0.001); the CARE group had lower SE increase than the CARE S group (-0.36 ± 0.22 D vs. -0.48 ± 0.27 D, P = 0.003); the OK and CARE groups had greater SFChT, central ChT, and superior ChT increases than the CARE S group (all P < 0.001); the OK group had lower nasal ChT increase than the CARE and CARE S groups (all P < 0.001). ChT increased in most regions after wearing the three lenses. For the OK group, the change in AL was negatively correlated with change in SFChT, nasal, and temporal ChT (P < 0.05). For the CARE and CARE S groups, the change in AL was negatively correlated with change in SFChT and superior ChT (P < 0.05).

Conclusions

OK and CARE lenses were more effective than CARE S lenses in myopia control for moderate myopic children over a 1-year follow-up period, which might be related to the different levels of ChT increases in various regions.