Mordi J A, Ciuffreda K J
SUNY/State College of Optometry, Department of Vision Sciences, New York 10010, USA.
Vision Res. 1998 Jun;38(11):1643-53. doi: 10.1016/s0042-6989(97)00336-2.
Although the progressive reduction in accommodative amplitude with increased age is well documented, little is known about several other aspects of static or steady-state accommodation to provide a comprehensive assessment of changes related to age and presbyopia. Static components of accommodation (tonic accommodation, depth-of-focus, slope of the stimulus/response function, and accommodative controller gain) were assessed objectively using an infrared (IR) optometer in 30 human subjects aged 21-50 years; depth-of-focus was also determined psychophysically as was accommodative amplitude. Tonic accommodation and the amplitude of accommodation decreased with increased age, whereas the subjective depth-of-focus increased; the other parameters remained unchanged. The decrease in tonic accommodation and amplitude of accommodation was attributed to biomechanical factors, whereas the increase in subjective depth-of-focus was believed to result from increased tolerance to defocus related to the gradual onset of presbyopia. Constancy of the objective depth-of-focus suggested absence of age effects on the neurologic control of reflex accommodation, whereas the lack of systematic change in slope and controller gain provided support for the Hess-Gullstrand theory of accommodation and presbyopia.
尽管随着年龄增长调节幅度逐渐降低这一点已有充分记录，但对于静态或稳态调节的其他几个方面，人们了解甚少，这些方面对于全面评估与年龄和老花眼相关的变化至关重要。使用红外（IR）验光仪对30名年龄在21至50岁的人类受试者的调节静态成分（张力性调节、焦深、刺激/反应函数斜率和调节控制器增益）进行了客观评估；焦深还通过心理物理学方法以及调节幅度来确定。张力性调节和调节幅度随年龄增长而降低，而主观焦深增加；其他参数保持不变。张力性调节和调节幅度的降低归因于生物力学因素，而主观焦深的增加被认为是由于与老花眼逐渐发生相关的对散焦耐受性增加所致。客观焦深的恒定表明年龄对反射性调节的神经控制没有影响，而斜率和控制器增益缺乏系统性变化为赫斯 - 古尔斯特兰德调节和老花眼理论提供了支持。
