Bossong Heather, Swann Michelle, Glasser Adrian, Das Vallabh E
Division of Sensory-Motor Systems, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA.
Invest Ophthalmol Vis Sci. 2009 Feb;50(2):966-73. doi: 10.1167/iovs.08-2686. Epub 2008 Nov 21.
This study was designed to use infrared photorefraction to measure accommodation in awake-behaving normal and strabismic monkeys and describe properties of photorefraction calibrations in these monkeys.
Ophthalmic trial lenses were used to calibrate the slope of pupil vertical pixel intensity profile measurements that were made with a custom-built infrared photorefractor. Day to day variability in photorefraction calibration curves, variability in calibration coefficients due to misalignment of the photorefractor Purkinje image and the center of the pupil, and variability in refractive error due to off-axis measurements were evaluated.
The linear range of calibration of the photorefractor was found for ophthalmic lenses ranging from -1 D to +4 D. Calibration coefficients were different across monkeys tested (two strabismic, one normal) but were similar for each monkey over different experimental days. In both normal and strabismic monkeys, small misalignment of the photorefractor Purkinje image with the center of pupil resulted in only small changes in calibration coefficients, that were not statistically significant (P>0.05). Off-axis measurement of refractive error was also small in the normal and strabismic monkeys (approximately 1 D to 2 D) as long as the magnitude of misalignment was <10 degrees.
Remote infrared photorefraction is suitable for measuring accommodation in awake, behaving normal, and strabismic monkeys. Specific challenges posed by the strabismic monkeys, such as possible misalignment of the photorefractor Purkinje image and the center of the pupil during either calibration or measurement of accommodation, that may arise due to unsteady fixation or small eye movements including nystagmus, results in small changes in measured refractive error.
本研究旨在利用红外光屈光测量法测量清醒行为状态下正常和斜视猴子的调节功能，并描述这些猴子光屈光测量校准的特性。
使用眼科试验镜片校准用定制红外光屈光仪进行的瞳孔垂直像素强度轮廓测量的斜率。评估了光屈光测量校准曲线的每日变异性、由于光屈光仪浦肯野图像与瞳孔中心未对准导致的校准系数变异性以及由于离轴测量导致的屈光不正变异性。
发现对于-1 D至+4 D范围内的眼科镜片，光屈光仪校准的线性范围存在。所测试的猴子（两只斜视猴子、一只正常猴子）的校准系数不同，但每只猴子在不同实验日的校准系数相似。在正常和斜视猴子中，如果光屈光仪浦肯野图像与瞳孔中心有小的未对准，校准系数只会有小的变化，且无统计学意义（P>0.05）。只要未对准幅度<10度，正常和斜视猴子离轴屈光不正测量值也较小（约1 D至2 D）。
远程红外光屈光测量法适用于测量清醒、行为正常和斜视猴子的调节功能。斜视猴子带来的特定挑战，例如在校准或调节测量期间，由于不稳定注视或包括眼球震颤在内的小眼球运动，可能导致光屈光仪浦肯野图像与瞳孔中心未对准，从而导致测量的屈光不正有小的变化。
