College of Optometry, University of Houston, 4901 Calhoun Road, Houston, TX 77204, United States.
Exp Eye Res. 2013 Aug;113:80-6. doi: 10.1016/j.exer.2013.05.017. Epub 2013 May 27.
If longitudinal studies of accommodation or accommodation restoration procedures are undertaken in rhesus monkeys, the methods used to induce and measure accommodation must remain reproducible over the study period. Stimulation of the Edinger-Westphal (EW) nucleus in anesthetized rhesus monkeys is a valuable method to understand various aspects of accommodation. A prior study showed reproducibility of EW-stimulated accommodation over 14 months after chronic electrode implantation. However, reproducibility over a period longer than this has not been investigated and therefore remains unknown. To address this, accommodation stimulation experiments in four eyes of two rhesus monkeys (13.7 and 13.8 years old) were evaluated over a period of 68 months. Carbachol iontophoresis stimulated accommodation was first measured with a Hartinger coincidence refractometer (HCR) two weeks before electrode implantation to determine maximum accommodative amplitudes. EW stimulus-response curves were initially measured with the HCR one month after electrode implantation and then repeated at least six times for each eye in the following 60 months. At 64 months, carbachol iontophoresis induced accommodation was measured again. At 68 months, EW stimulus-response curves were measured with an HCR and photorefraction every week over four consecutive weeks to evaluate the short-term reproducibility over one month. In the four eyes studied, long-term EW-stimulated accommodation decreased by 7.00 D, 3.33 D, 4.63 D, and 2.03 D, whereas carbachol stimulated accommodation increased by 0.18 D-0.49 D over the same time period. The short-term reproducibility of maximum EW-stimulated accommodation (standard deviations) over a period of four weeks at 68 months after electrode implantation was 0.48 D, 0.79 D, 0.55 D and 0.39 D in the four eyes. Since the long-term decrease in EW-stimulated accommodation is not matched by similar decreases in carbachol iontophoresis stimulated accommodation, the decline in accommodation cannot be due to the progression of presbyopia but is likely to result from variability in EW electrode position. Therefore, EW-stimulated accommodation in anesthetized monkeys is not appropriate for long-term longitudinal studies of age-related loss of accommodation or accommodation restoration procedures.
如果要在恒河猴中进行关于调节或调节恢复程序的纵向研究，那么在研究期间，用于诱导和测量调节的方法必须保持可重复性。麻醉恒河猴的 Edinger-Westphal（EW）核刺激是了解调节各个方面的一种有价值的方法。先前的一项研究表明，在慢性电极植入后 14 个月，EW 刺激调节具有可重复性。然而，在此期间以上的可重复性尚未得到研究，因此尚不清楚。为了解决这个问题，对两只恒河猴（13.7 岁和 13.8 岁）的四只眼睛进行了 68 个月的适应刺激实验。在电极植入前两周，用 Hartinger 符合折射计（HCR）首次测量了卡巴胆碱离子电渗疗法刺激的调节幅度，以确定最大调节幅度。在电极植入后一个月，用 HCR 最初测量 EW 刺激-反应曲线，然后在接下来的 60 个月内，对每只眼睛至少重复测量六次。在 64 个月时，再次测量卡巴胆碱离子电渗疗法诱导的调节。在 68 个月时，每周连续四周用 HCR 和光折射法测量 EW 刺激-反应曲线，以评估一个月内的短期可重复性。在研究的四只眼睛中，长期 EW 刺激调节下降了 7.00 D、3.33 D、4.63 D 和 2.03 D，而卡巴胆碱刺激调节在此期间增加了 0.18 D-0.49 D。在电极植入后 68 个月的四周期间，四只眼睛的最大 EW 刺激调节（标准偏差）的短期可重复性分别为 0.48 D、0.79 D、0.55 D 和 0.39 D。由于 EW 刺激调节的长期下降没有被类似的卡巴胆碱离子电渗疗法刺激调节下降所匹配，因此调节的下降不可能是由于远视的进展，而是可能由于 EW 电极位置的变化所致。因此，麻醉恒河猴的 EW 刺激调节不适合长期纵向研究与年龄相关的调节丧失或调节恢复程序。
