Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.
National Clinical Research Center for Ocular Diseases, Wenzhou, China.
Ophthalmic Physiol Opt. 2022 Sep;42(5):1124-1132. doi: 10.1111/opo.12996. Epub 2022 May 22.
To investigate whether the treatment zone (TZ) decentration in orthokeratology (OK) lenses affects retinal expansion in Chinese children with myopia.
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 (d ). 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 = ax + 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.
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 d (β = -0.37, p = 0.03) (R = 0.34, p = 0.002). When compared with smaller d (0.45 ± 0.15 mm), a larger d (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; K : 0.35 ± 0.11 vs. 0.39 ± 0.09, p = 0.02; K : -0.42 ± 0.08 vs. -0.46 ± 0.08, p = 0.004).
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.
研究角膜塑形术（OK）镜片的治疗区（TZ）偏心是否会影响中国儿童近视的视网膜扩张。
评估了 30 名 8 至 13 岁的儿童，共 13 个月，包括 12 个月的 OK 镜片佩戴和随后停止镜片佩戴 1 个月。在 0、1、3、6、9、12 和 13 个月时测量角膜地形图。计算 OK 镜片的 TZ 偏心，并根据加权平均偏心（d）的中位数将受试者分为小偏心组（S 组）和大偏心组（L 组）。在睫状肌麻痹下，在 0 和 13 个月时测量中央视网膜、10°、20°和 30°鼻侧和颞侧的中央眼轴（AL）和外周眼长（PEL）。应用二次多项式（y=ax+bx+c）和线性拟合（y=Kx+B）来描述外周相对眼长（PREL），并使用系数“a”和“K”来描述眼的形状。
一年中平均 AL 增长 0.28±0.17mm。在多元线性回归模型中，AL 伸长与基线年龄（β=-0.41，p=0.01）和 d（β=-0.37，p=0.03）相关（R2=0.34，p=0.002）。与较小的 d（0.45±0.15mm）相比，较大的 d（0.89±0.17mm）与眼生长速度较慢有关（中央：0.20±0.13mm 与 0.35±0.17mm，p=0.009；10°鼻侧：0.26±0.18mm 与 0.45±0.21mm，p=0.02；10°颞侧：0.17±0.14mm 与 0.32±0.19mm，p=0.02），视网膜形状更扁（“a”：-0.13±0.02 与-0.14±0.02，p=0.02；K：0.35±0.11 与 0.39±0.09，p=0.02；K：-0.42±0.08 与-0.46±0.08，p=0.004）。
使用 OK 镜片时 TZ 偏心较大与轴向生长较慢和视网膜形状更扁有关。TZ 偏心引起局部离焦变化，可能抑制近视进展。这些发现可能对改善近视控制的光学设计具有重要意义。
