Reproducibility of carbachol stimulated accommodation in rhesus monkeys
- 作者：Mark Wendt ; Adrian Glasser ; aglasser@uh.edu
- 关键词：presbyopia ; accommodation ; carbachol ; iontophoresis ; monkey
- 刊名：Experimental Eye Research
- 出版年：2012
- 期刊代码：293_00144835
- 类别：med
- 出版时间：June, 2012
- 卷：99
- 期：Complete
- 页码：89-97
- 文件大小：1045 K
摘要
Approaches are being explored to restore accommodation to the presbyopic eye. Some of these approaches can be tested in monkeys by stimulating accommodation in various ways including using carbachol iontophoresis. Knowledge of the repeatability of carbachol iontophoresis stimulated accommodation in the monkey phakic eye is necessary to understand the variability of this method of evaluating accommodation. Data from 9 to 10 separate carbachol iontophoresis experiments performed on phakic eyes from 8 monkeys were retrospectively analyzed. For each experiment, carbachol was applied iontophoretically to the eyes of anesthetized monkeys and refraction generally measured every two minutes until accommodation reached a plateau. Repeated experiments were performed in each monkey over periods ranging from 10 to 18 months. Maximum accommodation measured for each monkey ranged from 11.1聽D to 18.3聽D with standard deviations from 0.8聽D to 2.1聽D and differences in accommodative amplitude varying from 2.2聽D to 7.5聽D. Time to reach maximum accommodation ranged from 18 to 64聽min in individual experiments. Averaged time-courses indicate that maximum accommodation is generally achieved between 10 and 20聽min after carbachol administration. Although carbachol iontophoresis is considered a reliable method to stimulate maximum accommodation in anesthetized monkeys, the amplitude achieved typically varies by more than 2聽D. Presbyopia treatments evaluated in this way in phakic monkeys would need to show an increase in accommodation of over 2聽D to clearly demonstrate that the treatments work when being tested with carbachol iontophoresis stimulation.