Anderson Heather A, Hentz Gloria, Glasser Adrian, Stuebing Karla K, Manny Ruth E
College of Optometry, University of Houston, Houston, Texas, USA.
Invest Ophthalmol Vis Sci. 2008 Jul;49(7):2919-26. doi: 10.1167/iovs.07-1492. Epub 2008 Mar 7.
Guidelines for predicting accommodative amplitude by age are often based on subjective push-up test data that overestimate the accommodative response. Studies in which objective measurements were used have defined expected amplitudes for adults, but expected amplitudes for children remain unknown. In this study, objective methods were used to measure accommodative amplitude in a wide age range of individuals, to define the relationship of amplitude and age from age 3.
Accommodative responses were measured in 140 subjects aged 3 to 40 years. Measurements were taken with the Grand Seiko autorefractor (RyuSyo Industrial Co., Ltd., Kagawa, Japan) as the subjects viewed a high-contrast target at 33 cm through minus lenses of increasing power until the responses showed no further increase in accommodation.
The maximum accommodative amplitude of each subject was plotted by age, and a curvilinear function fit to the data: y = 7.33 - 0.0035(age - 3)(2) (P < 0.001). Tangent analysis of the fit indicated that the accommodative amplitude remained relatively stable until age 20. Data from this study were then pooled with objective amplitudes from previous studies of adults up to age 70. A sigmoidal function was fit to the data: y = 7.083/(1 + e([0.2031(age-36.2)-0.6109])) (P < 0.001). The sigmoidal function indicated relatively stable amplitudes below age 20 years, a rapid linear decline between 20 and 50 years, and a taper to 0 beyond 50 years.
These data indicate that accommodative amplitude decreases in a curvilinear manner from 3 to 40 years. When combined with data from previous studies, a sigmoidal function describes the overall trend throughout life with the biggest decrease occurring between 20 and 50 years.
根据年龄预测调节幅度的指南通常基于主观的推近法测试数据，这些数据高估了调节反应。使用客观测量方法的研究已经确定了成年人的预期调节幅度，但儿童的预期调节幅度仍然未知。在本研究中，采用客观方法测量了广泛年龄范围个体的调节幅度，以确定3岁及以上年龄调节幅度与年龄的关系。
对140名年龄在3至40岁的受试者测量调节反应。当受试者通过度数逐渐增加的负透镜观察33 cm处的高对比度目标时，使用精工自动验光仪（日本香川县龙生工业株式会社）进行测量，直到反应显示调节不再进一步增加。
将每个受试者的最大调节幅度按年龄绘制，并对数据拟合曲线函数：y = 7.33 - 0.0035(年龄 - 3)²（P < 0.001）。对拟合曲线的切线分析表明，调节幅度在20岁之前保持相对稳定。然后将本研究的数据与先前对70岁以下成年人的客观调节幅度研究数据合并。对数据拟合S形函数：y = 7.083 / (1 + e^([0.2031(年龄 - 36.2) - 0.6109]))（P < 0.001）。S形函数表明，20岁以下调节幅度相对稳定，20至50岁之间迅速线性下降，50岁以后逐渐趋近于0。
这些数据表明，调节幅度在3至40岁之间呈曲线下降。与先前研究的数据相结合时，S形函数描述了一生中的总体趋势，最大降幅发生在20至50岁之间。
