.
Invest Ophthalmol Vis Sci. 2020 Jul 1;61(8):45. doi: 10.1167/iovs.61.8.45.
To evaluate the relationship between refractive error, circadian phase, and melatonin with consideration of prior light exposure, physical activity, and sleep.
Healthy young myopic (spherical equivalent refraction [SER] ≤-0.50DS) and emmetropic adults underwent noncycloplegic autorefraction and axial length (AL) measures. Objective measurements of light exposure, physical activity, and sleep were captured across 7 days by wrist-worn Actiwatch-2 devices. Questionnaires assessed sleep quality and chronotype. Hourly evening saliva sampling during a dim-light melatonin onset (DLMO) protocol evaluated circadian phase, and both morning serum and saliva samples were collected. Liquid chromatography/mass spectrometry quantified melatonin.
Subjects (n = 51) were aged 21.4 (interquartile range, 20.1-24.0) years. Melatonin was significantly higher in the myopic group at every evening time point and with both morning serum and saliva sampling (P ≤ 0.001 for all). DLMO-derived circadian phase did not differ between groups (P = 0.98). Multiple linear regression analysis demonstrated significant associations between serum melatonin and SER (B = -.34, β = -.42, P = 0.001), moderate activity (B = .009, β = .32, P = 0.01), and mesopic illumination (B = -.007, β = -.29, P = 0.02), F(3, 46) = 7.23, P < 0.001, R2 = 0.32, R2adjusted = .28. Myopes spent significantly more time exposed to "indoor" photopic illumination (3 to ≤1000 lux; P = 0.05), but "indoor" photopic illumination was not associated with SER, AL, or melatonin, and neither sleep, physical activity, nor any other light exposure metric differed significantly between groups (P > 0.05 for all).
While circadian phase is aligned in adult myopes and emmetropes, myopia is associated with both elevated serum and salivary melatonin levels. Prospective studies are required to ascertain whether elevated melatonin levels occur before, during, or after myopia development.
评估在考虑先前的光照暴露、体力活动和睡眠的情况下，屈光不正、昼夜节律相位和褪黑素之间的关系。
健康的年轻近视（等效球镜屈光度 [SER]≤-0.50DS）和正视成年人接受非睫状肌麻痹自动折射和眼轴（AL）测量。通过腕戴 Actiwatch-2 设备在 7 天内对光照暴露、体力活动和睡眠进行客观测量。睡眠质量和昼夜类型的调查问卷进行评估。在暗光诱导褪黑素开始（DLMO）方案中每小时采集一次夜间唾液样本以评估昼夜节律相位，同时采集早晨血清和唾液样本。液相色谱/质谱法对褪黑素进行定量分析。
受试者（n=51）年龄为 21.4（四分位距，20.1-24.0）岁。在每个夜间时间点以及两次早晨血清和唾液采样中，近视组的褪黑素水平均显著升高（所有 P≤0.001）。两组之间的 DLMO 衍生昼夜节律相位无差异（P=0.98）。多元线性回归分析显示，血清褪黑素与 SER（B=-0.34，β=-0.42，P=0.001）、中度活动（B=0.009，β=0.32，P=0.01）和中光照明（B=-0.007，β=-0.29，P=0.02）呈显著相关，F（3,46）=7.23，P＜0.001，R2=0.32，R2adjusted=0.28。近视者暴露于“室内”高光照明（3 至≤1000 勒克斯）的时间明显更长（P=0.05），但“室内”高光照明与 SER、AL 或褪黑素均无关联，且两组之间的睡眠、体力活动或任何其他光照暴露指标均无显著差异（所有 P＞0.05）。
尽管成年近视者和正视者的昼夜节律相位一致，但近视与血清和唾液褪黑素水平升高有关。需要前瞻性研究来确定褪黑素水平升高是发生在近视发展之前、期间还是之后。
