Carle Corinne Frances, James Andrew Charles, Rosli Yanti, Maddess Ted
John Curtin School of Medical Research, Eccles Institute of Neuroscience, The Australian National University, Canberra, ACT, Australia.
ANU Medical School, The Australian National University, Canberra, ACT, Australia.
Front Neurol. 2019 Mar 12;10:203. doi: 10.3389/fneur.2019.00203. eCollection 2019.
Multifocal pupillographic objective perimetry (mfPOP) is being developed as an alternative to standard visual perimetry. In mfPOP, pupil responses to sparse multifocal luminance stimuli are extracted from the overall composite response. These individual test-region responses are subject to gain-control which is dependent on the temporal and spatial density of stimuli. This study aimed to localize this gain within the pupil pathway. Pupil constriction amplitudes of 8 subjects (41.5 ±12.7 y, 4 male) were measured using a series of 14 mfPOP stimulus variants. The temporal density of stimulus signal at the levels of retina, pretectal olivary nuclei (PON), and Edinger-Westphal nuclei (EWN) were controlled using a combination of manipulation of the mean interval between stimulus presentations (3 or 6 stimuli/s/hemiretina) and the restriction of stimuli to specific subsets of the 24 visual field test-regions per eye (left or right eye, left or right hemifield, or nasal or temporal hemifield). No significant difference was observed between mfPOP variants with differing signal density at the retina or PON but matched density at the other levels. In contrast, where signal density differed at the EWN but was the same at the retinal and PON levels e.g., between 3 stim/s and variants, significant reductions in constriction amplitudes were observed [ = -2.07 to -2.50, all < 0.05]. Similar, although more variable, relationships were seen using nasal, and temporal hemifield stimuli. Results suggest that the majority of gain-control in the subcortical pupillary pathway occurs at the level of the EWN.
多焦点瞳孔客观视野计（mfPOP）正在被开发作为标准视觉视野计的替代方法。在mfPOP中，从整体复合反应中提取瞳孔对稀疏多焦点亮度刺激的反应。这些单个测试区域的反应会受到增益控制，该控制取决于刺激的时间和空间密度。本研究旨在确定该增益在瞳孔通路中的位置。使用一系列14种mfPOP刺激变体测量了8名受试者（41.5±12.7岁，4名男性）的瞳孔收缩幅度。通过操纵刺激呈现之间的平均间隔（3或6次刺激/秒/半视网膜）以及将刺激限制在每只眼睛24个视野测试区域的特定子集中（左眼或右眼、左半视野或右半视野、或鼻侧半视野或颞侧半视野），来控制视网膜、顶盖前橄榄核（PON）和动眼神经副核（EWN）水平上刺激信号的时间密度。在视网膜或PON处信号密度不同但其他水平处密度匹配的mfPOP变体之间未观察到显著差异。相比之下，当EWN处信号密度不同但视网膜和PON水平处信号密度相同时，例如在3次刺激/秒和变体之间，观察到收缩幅度显著降低[=-2.07至-2.50，所有<0.05]。使用鼻侧和颞侧半视野刺激也观察到了类似但更具变异性的关系。结果表明，皮质下瞳孔通路中的大部分增益控制发生在EWN水平。
