Baumeister Martin, Wendt Mark, Glasser Adrian
Department of Ophthalmology, Frankfurt University, Frankfurt am Main, Germany.
Invest Ophthalmol Vis Sci. 2010 Oct;51(10):5378-90. doi: 10.1167/iovs.10-5269. Epub 2010 May 19.
In humans, accommodative and disaccommodative dynamics depend on response amplitude and starting point. The purpose of this study was to determine the influence of amplitude and starting point on open-loop accommodative dynamics in Edinger-Westphal (EW)-stimulated, anesthetized rhesus monkeys of different ages.
One eye each of two younger and two older iridectomized rhesus monkeys, (aged 6.8, 8.9, 15.0, and 16.3 years) were studied. The experiment was repeated in one eye of one younger monkey. Lens thickness changes were recorded by dynamic ultrasound biometry at 100 Hz. Stimuli used produced accommodative responses: (1) starting from baseline with increasing amplitudes; (2) from increasing starting points to maximum accommodation; and (3) from increasing starting points with a constant amplitude of 1 D. The lens thickness measurements were converted into accommodation and velocities and accelerations of the responses were determined by using a two-point difference algorithm.
Maximum accommodative amplitudes ranged from 4.68 to 6.37 D in the older monkeys and 9.33 to 11.59 D in the younger monkeys. The peak velocity of accommodation and disaccommodation increased linearly with response amplitude. Peak velocity and peak acceleration of accommodation and disaccommodation were independent of the response starting point. Subtle variations in disaccommodative response peak velocities were found to vary with age.
The results suggest that, in anesthetized rhesus monkeys, disaccommodative rather than accommodative dynamics may be more sensitive to age-related changes and that, unlike in conscious human subjects, the starting configuration of the accommodative plant has little influence on accommodative dynamics.
在人类中，调节和放松调节的动力学取决于反应幅度和起始点。本研究的目的是确定幅度和起始点对不同年龄的经动眼神经核（EW）刺激的麻醉恒河猴的开环调节动力学的影响。
研究了两只年轻和两只年老的虹膜切除恒河猴（年龄分别为6.8、8.9、15.0和16.3岁）的每只眼睛。在一只年轻猴子的一只眼睛上重复了该实验。通过动态超声生物测量法以100 Hz记录晶状体厚度变化。使用的刺激产生调节反应：（1）从基线开始，幅度逐渐增加；（2）从逐渐增加的起始点到最大调节；（3）从逐渐增加的起始点开始，幅度恒定为1 D。将晶状体厚度测量值转换为调节量，并使用两点差分算法确定反应的速度和加速度。
老年猴子的最大调节幅度在4.68至6.37 D之间，年轻猴子的最大调节幅度在9.33至11.59 D之间。调节和放松调节的峰值速度随反应幅度线性增加。调节和放松调节的峰值速度和峰值加速度与反应起始点无关。发现放松调节反应峰值速度的细微变化随年龄而变化。
结果表明，在麻醉的恒河猴中，放松调节而非调节动力学可能对与年龄相关的变化更敏感，并且与清醒的人类受试者不同，调节装置的起始配置对调节动力学影响很小。
