Flynn-Evans Erin E, Tabandeh Homayoun, Skene Debra J, Lockley Steven W
Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.
Retina-Vitreous Associates, Beverly Hills, California, USA.
J Biol Rhythms. 2014 Jun;29(3):215-224. doi: 10.1177/0748730414536852. Epub 2014 Jun 10.
Light is the major environmental time cue that synchronizes the endogenous central circadian pacemaker, located in the suprachiasmatic nuclei of the hypothalamus, and is detected exclusively by the eyes primarily via specialized non-rod, non-cone ganglion cell photoreceptors. Consequently, most blind people with no perception of light (NPL) have either nonentrained or abnormally phased circadian rhythms due to this inability to detect light. Conversely, most visually impaired participants with some degree of light perception (LP) exhibit normal entrainment, emphasizing the functional separation of visual and "nonvisual" photoreception. The aims of the study were to identify the prevalence of circadian disorders in blind women, with the further aim of examining how eye disease may relate to the type of circadian disorder. Participants (n = 127, age 50.8 ± 13.4 years) completed an 8-week field study including daily sleep diaries and sequential 4 to 8 hourly urine collections over 48 h on 2 to 3 occasions separated by at least 2 weeks. Circadian type was determined from the timing and time course of the melatonin rhythm measured by cosinor-derived urinary 6-sulfatoxymelatonin rhythm peak. Of the participants with NPL (n = 41), the majority were abnormally phased (24%) or nonentrained (39%), with 37% classified as normally entrained. Of the participants with LP (n = 86), the majority were normally entrained (69%). Eighteen LP participants (21%) were abnormally phased (8 advanced, 10 delayed). Nine LP participants (10%) were nonentrained. The eye conditions most associated with abnormal phase and/or nonentrained circadian rhythms were bilateral enucleation (67%) and retinopathy of prematurity (57%). By contrast, 84% of participants with retinitis pigmentosa and 83% of those with age-related macular degeneration were normally entrained. These findings suggest that the etiology of blindness in addition to LP status is related to an individual's ability to process the circadian light signal.
光是主要的环境时间线索，它能使位于下丘脑视交叉上核的内源性中枢昼夜节律起搏器同步，并且光主要通过专门的非视杆、非视锥神经节细胞光感受器被眼睛唯一检测到。因此，大多数没有光感知（NPL）的盲人由于无法检测到光，其昼夜节律要么没有被调节，要么相位异常。相反，大多数有一定程度光感知（LP）的视力受损参与者表现出正常的节律调节，这强调了视觉和“非视觉”光接收的功能分离。本研究的目的是确定失明女性中昼夜节律障碍的患病率，进一步目的是研究眼病与昼夜节律障碍类型之间的关系。参与者（n = 127，年龄50.8±13.4岁）完成了一项为期8周的现场研究，包括每日睡眠日记以及在2至3个场合下，每次间隔至少2周，连续48小时每4至8小时收集一次尿液。昼夜节律类型由通过余弦分析得出的尿6 - 硫酸氧褪黑素节律峰值所测量的褪黑素节律的时间和时间进程来确定。在没有光感知（NPL）的参与者（n = 41）中，大多数相位异常（24%）或未被调节（39%），37%被归类为正常调节。在有光感知（LP）的参与者（n = 86）中，大多数正常调节（69%）。18名有光感知（LP）的参与者（21%）相位异常（8名提前，10名延迟）。9名有光感知（LP）的参与者（10%）未被调节。与相位异常和/或未被调节的昼夜节律最相关的眼部疾病是双侧眼球摘除（67%）和早产儿视网膜病变（57%）。相比之下，84%的视网膜色素变性参与者和83%的年龄相关性黄斑变性参与者节律正常。这些发现表明，除了光感知状态外，失明的病因还与个体处理昼夜节律光信号的能力有关。
