Search Results (2)

Background/Objectives: Myopia progression is strongly associated with axial length (AL) elongation, and orthokeratology (Ortho-K) lens design may influence treatment outcomes. This study has the aim to evaluate the impact of lens customization as optical zone diameter between specific higher-order aberrations (HOA) and axial length (AL) changes in myopic children. Methods: This retrospective study evaluated 66 Caucasian myopic children (mean age, 13.3 ± 1.4 years, 60% male) fitted with Ortho-K lenses with varying back optic zone diameters (BOZD, 4.7–6.0 mm) in a Spanish optometric clinic. Baseline mean spherical equivalent (sphere + 1/2 cylinder) was −2.94 ± 1.24 D and AL = 24.52 ± 0.80 mm. Results: After 12 months, children fitted with smaller BOZDs showed significantly less axial elongation than those with larger BOZDs (0.08 ± 0.12 mm vs. 0.15 ± 0.10 mm, p < 0.001) and smaller plus power ring diameter (PPRD). Differences in AL change were observed between PPRD subgroups (larger and smaller than 4.5 mm). HOA revealed distinct patterns: vertical coma increased significantly only in the PPRD > 4.5 mm group (p = 0.003), horizontal coma increased significantly only in the PPRD < 4.5 mm group (p = 0.004), while total coma increased in both, without intergroup differences. Both PPRD subgroups demonstrated significant increases in spherical aberration (p < 0.001). Conclusions: These findings suggest that reducing BOZD, and consequently PPRD, can slow AL elongation more effectively than standard designs, although optical side effects require consideration. Further studies should clarify the interplay of BOZD, PPRD, and pupil size in myopia control. Full article

We compared the efficacy of controlling the annual increase in axial length (AL) in myopic Caucasian children based on two parameters: the back optic zone diameter (BOZD) of the orthokeratology (OK) lens and plus power ring diameter (PPRD) or mid-peripheral annular ring of corneal steepening. Data from 71 myopic patients (mean age, 13.34 ± 1.38 years; range, 10–15 years; 64% male) corrected with different BOZD OK lenses (DRL, Precilens) were collected retrospectively from a Spanish optometric clinic. The sample was divided into groups with BOZDs above or below 5.00 mm and the induced PPRD above or below 4.5 mm, and the relation to AL and refractive progression at 12 months was analyzed. Three subgroups were analyzed, i.e., plus power ring (PPR) inside, outside, or matching the pupil. The mean baseline myopia was −3.11 ± 1.46 D and the AL 24.65 ± 0.88 mm. Significant (p < 0.001) differences were found after 12 months of treatment in the refractive error and AL for the BOZD and PPRD. AL changes in subjects with smaller BOZDs decreased significantly regarding larger diameters (0.09 ± 0.12 and 0.15 ± 0.11 mm, respectively); in subjects with a horizontal sector of PPRD falling inside the pupil, the AL increased less (p = 0.035) than matching or outside the pupil groups by 0.04 ± 0.10 mm, 0.10 ± 0.11 mm, and 0.17 ± 0.12 mm, respectively. This means a 76% lesser AL growth or 0.13 mm/year in absolute reduction. OK corneal parameters can be modified by changing the OK lens designs, which affects myopia progression and AL elongation. Smaller BOZD induces a reduced PPRDs that slows AL elongation better than standard OK lenses. Further investigations should elucidate the effect of pupillary diameter, PPRD, and power change on myopia control. Full article