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Purpose: The aim of this study was to evaluate the short‐term effects of peripheral gradient high‐addition multifocal soft contact lenses (MFSCLs) and orthokeratology (Ortho‐K lenses) on visual performance in myopic children. Methods: Thirty myopic children participated in this prospective study. Each participant wore different sets of lenses in the following sequence: single‐vision spectacles (SVSPs) as a control, MFSCLs and Ortho‐K lenses. Ocular aberrations, topography, high‐contrast visual acuity (HCVA), low‐contrast visual acuity (LCVA) and accommodation of the right eye were measured with each type of correction on a different day. Results: Compared with SVSPs, high‐addition MFSCLs and Ortho‐K lenses significantly increased all items of aberrations (all p < 0.05) except trefoil (p = 0.17). MFSCLs induced less coma, root mean square of the third‐order aberration (RMS3) and higher order aberrations than Ortho‐K lenses (all p < 0.05). No significant difference in HCVA was found across the three correction types (F = 1.19, p = 0.39). In terms of LCVA, MFSCLs performed significantly poorer than SVSPs (difference, 0.16 logMAR; p = 0.001) and slightly worse than Ortho‐K lenses (difference, 0.08 logMAR; p = 0.35). No significant difference in decentration was found between the two types of contact lenses, and no associations were observed between decentration and visual acuity at both high‐ and low‐contrast levels (all p > 0.05). For MFSCLs, decentration was positively related to coma (r = 0.43, p = 0.02) and RMS3 (r = 0.44, p = 0.02), which was not the case for Ortho‐K lenses. Accommodative facility was worse with MFSCLs than Ortho‐K lenses (p = 0.001). Conclusion: Multifocal soft contact lenses differed from Ortho‐K lenses in aberration profile and LCVA, although decentration was similar. Decentration <1 mm had minimal influence on both HCVA and LCVA for either type of correction, but significantly increased third‐order aberrations for MFSCLs, but not Ortho‐K lenses. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether the treatment zone (TZ) decentration in orthokeratology (OK) lenses affects retinal expansion in Chinese children with myopia. Methods: Children aged 8 to 13 years (n = 30) were assessed over 13 months comprising 12 months of OK lens wear followed by discontinuation of lens wear for 1 month. Corneal topography was measured at 0, 1, 3, 6, 9, 12 and 13 months. TZ decentration of the OK lens was calculated, and subjects were subdivided into a small decentration group (group S) and a large decentration group (group L) based on the median value of the weighted average decentration (dave). Central axial length (AL) and peripheral eye lengths (PELs) at the central retina, as well as 10°, 20° and 30° nasally and temporally were measured at 0 and 13 months under cycloplegia. Second‐order polynomial (y = ax2 + bx + c) and linear fits (y = Kx + B) were applied to the peripheral relative eye length (PREL), and the coefficients 'a' and 'K' were used to describe the shape of the eye. Results: Mean AL growth for one year was 0.28 ± 0.17 mm. In a multiple linear regression model, AL elongation was related to the baseline age (β = −0.41, p = 0.01) and the dave (β = −0.37, p = 0.03) (R2 = 0.34, p = 0.002). When compared with smaller dave (0.45 ± 0.15 mm), a larger dave (0.89 ± 0.17 mm) was associated with slower ocular growth (central: 0.20 ± 0.13 mm vs. 0.35 ± 0.17 mm, p = 0.009; 10° nasal: 0.26 ± 0.18 mm vs. 0.45 ± 0.21 mm, p = 0.02; 10° temporal: 0.17 ± 0.14 mm vs. 0.32 ± 0.19 mm, p = 0.02) and more oblate retina shape ('a': −0.13 ± 0.02 vs. −0.14 ± 0.02, p = 0.02; Knasal: 0.35 ± 0.11 vs. 0.39 ± 0.09, p = 0.02; Ktemporal: −0.42 ± 0.08 vs. −0.46 ± 0.08, p = 0.004). Conclusions: Greater TZ decentration with the use of OK lenses was associated with slower axial growth and a more oblate retinal shape. TZ decentration caused local defocusing changes, which may inhibit myopic progression. These findings may have important implications for improving optical designs for myopia control. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the effect of orthokeratology (OK) on accommodative function and aberrations, to explore the correlations between them and determine what role they play in myopia control. Methods: In this prospective case‐controlled study, 61 children were divided into an OK (n = 30) and a single‐vision spectacles (SVS) (n = 31) group. Accommodation and ocular wavefront aberrations in the OK group were measured at baseline and after 1, 3, 6, 9 and 12 months of OK wear, and again at 1 month after stopping OK (13th month). The same procedure was performed in the SVS group at baseline and at 3, 6 and 12 months. Axial length (AL), accommodative lag area and aberrations including spherical aberration (SA), coma and total higher‐order aberrations (HOAs) were analysed. Results: During OK wear, the accommodative lag area at each visit was lower than the baseline level (all p < 0.01); all aberrations at each visit were higher than pre‐treatment (all p < 0.001). After 1 month of OK treatment, changes in accommodative lag area and SA did not show significant correlation (p = 0.16), but after OK cessation these changes were correlated (p = 0.01). In the OK group, multivariate regression analysis showed changes in accommodative lag area were associated with AL progression in the first 6 months but not in the 1‐year analysis. For the SVS group, there were no significant changes in the accommodative lag area or any aberrations during the study period. Conclusions: Increased HOAs and improved accommodative accuracy were observed during OK treatment, but began to regress after the cessation of OK. A significant positive correlation between improved accommodative accuracy and slowed axial elongation was only observed during the first 6 months of treatment. [ABSTRACT FROM AUTHOR]

Purpose: This prospective study assessed the influence of wearing and then discontinuing orthokeratology (OK) lenses on retinal shape and peripheral refraction in myopic children.Methods: Fifty-eight myopic children (age 8-12 years) were equally divided into an OK group and a single vision spectacles (SVS) group. After 12 months of OK, it was discontinued for 1 month. Peripheral eye length (PEL), relative peripheral refraction (RPR), and corneal parameters were measured in the right eye on the nasal and temporal retinal sides at baseline, 6 months, and 12 months (13 months in OK group) visits.Results: In the SVS group, faster elongation of the temporal side PEL made the eyes more asymmetric and prolate, developing a temporal pointed shape. In the OK group, the nasal retinal side PEL grew faster, the nasal RPR developed less hyperopic defocus, and the eye shape became more symmetric and less prolate. The central cornea became thinner and flattened, while the peripheral cornea became steeper. Changes in corneal thickness, relative peripheral corneal power, and K-values were no significant differences for the OK and SVS groups at 12 months.Conclusions: The cornea reverted to be no difference with myopic children with SVS after 1 month discontinuation of OK. The retinal shape of SVS eyes became more asymmetric and prolate with myopia progression. OK remodelled retinal shape to be less asymmetric and less prolate. [ABSTRACT FROM AUTHOR]