目的:记录学龄前儿童屈光和屈光成分一年的变化。
方法:儿童,3-5岁,在嘉定区,上海,被跟踪了一年。每次访问,轴向长度(AL),睫状肌麻痹下的屈光(1%环培酮),球形屈光度(DS),圆柱屈光度(DC),测量球面等效屈光度(SER)和角膜曲率半径(CR)。
结果:该研究包括458名儿童的458只右眼。DS的平均变化,DC和SER为0.02±0.35D,-0.02±0.33D和0.01±0.37D,而AL的平均值变化,CR和晶状体屈光力(LP)为0.27±0.10mm,0.00±0.04mm和-0.93±0.49D。SER的变化与基线SER呈线性关系(系数=-0.147,p<0.001)。当基线SER为1.05D时(95%CI=0.21至2.16),SER的变化为0D。基线SER也与LP的变化线性相关(系数=0.104,p=0.013),但与AL的变化(p=0.957)或CR的变化(p=0.263)无关。
结论:在基线SER小于+1.00D的眼中,LP损失比轴向伸长率高,导致屈光远视偏移,而对于那些基线SER在这个范围内的人来说,与轴向伸长相比,LP损失减少了,导致近视的转变。该模型表明了人类屈光的稳态,并解释了屈光发育如何导致轻度远视的首选状态。
OBJECTIVE: To document one-year changes in refraction and refractive components in preschool children.
METHODS: Children, 3-5 years old, in the Jiading District, Shanghai, were followed for one year. At each visit, axial length (AL), refraction under cycloplegia (1% cyclopentolate), spherical dioptres (DS), cylinder dioptres (DC), spherical equivalent refraction (SER) and corneal curvature radius (CR) were measured.
RESULTS: The study included 458 right eyes of 458 children. The mean changes in DS, DC and SER were 0.02 ± 0.35 D, -0.02 ± 0.33 D and 0.01 ± 0.37 D, while the mean changes in AL, CR and lens power (LP) were 0.27 ± 0.10 mm, 0.00 ± 0.04 mm and - 0.93 ± 0.49 D. The change in the SER was linearly correlated with the baseline SER (coefficient = -0.147, p < 0.001). When the baseline SER was at 1.05 D (95% CI = 0.21 to 2.16), the change in SER was 0 D. The baseline SER was also linearly associated with the change in LP (coefficient = 0.104, p = 0.013), but not with the change in AL (p = 0.957) or with the change in CR (p = 0.263).
CONCLUSIONS: In eyes with a baseline SER less than +1.00 D, LP loss was higher compared to axial elongation, leading to hyperopic shifts in refraction, whereas for those with baseline SER over this range, loss of LP compared to axial elongation was reduced, leading to myopic shifts. This model indicated the homeostasis of human refraction and explained how refractive development leads to a preferred state of mild hyperopia.