Bouffard Marc A
Continuum (Minneap Minn). 2019 Oct;25(5):1194-1214. doi: 10.1212/CON.0000000000000771.
The goal of this article is to review the anatomy and physiology of pupillary function and then employ that information to develop a comprehensive framework for understanding and diagnosing pupillary disorders.
The contribution of rods and cones to the pupillary light reflex has long been known. A third photosensitive cell type, the intrinsically photosensitive retinal ganglion cell, has recently been discovered. This cell type employs melanopsin to mediate a portion of the pupillary light reflex independent of rods and cones (the postillumination pupillary response) and photic regulation of circadian rhythm.
The autonomic nervous system regulates pupil size in response to stimuli. The parasympathetic nervous system causes miosis in response to light and near visual stimuli. These stimuli activate supranuclear pathways that project to the Edinger-Westphal nuclei. The sympathetic nervous system causes mydriasis in response to a variety of arousing factors, both physiologic (wakefulness) and pathologic (pain). Abnormalities of physiologic function cause disturbances of pupil size, shape, and response to stimuli. The clinical approach to pupillary abnormalities should focus on the clinical and pharmacologic assessment of the pupil's expected response to diverse stimuli.
本文旨在回顾瞳孔功能的解剖学和生理学知识，然后利用这些信息构建一个理解和诊断瞳孔疾病的综合框架。
视杆细胞和视锥细胞对瞳孔光反射的作用早已为人所知。最近发现了第三种感光细胞类型，即内在光敏性视网膜神经节细胞。这种细胞类型利用黑素视蛋白介导部分独立于视杆细胞和视锥细胞的瞳孔光反射（光照后瞳孔反应）以及昼夜节律的光调节。
自主神经系统根据刺激调节瞳孔大小。副交感神经系统在对光和近距视觉刺激作出反应时导致瞳孔缩小。这些刺激激活投射到动眼神经副核的核上通路。交感神经系统在对各种激发因素作出反应时导致瞳孔散大，这些因素包括生理因素（清醒）和病理因素（疼痛）。生理功能异常会导致瞳孔大小、形状及对刺激反应的紊乱。瞳孔异常的临床处理应侧重于对瞳孔对各种刺激的预期反应进行临床和药理学评估。
