Analogs of microgravity: the function of Schlemm's canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects

作     者：Wei Chen Zhi-Qi Chen Yan Xiang Chao-Hua Deng Hong Zhang Jun-Ming Wang 

作者机构：Department of OphthalmologyTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030Hubei ProvinceChina 

出 版 物：《International Journal of Ophthalmology(English edition)》 (国际眼科杂志（英文版）)

年 卷 期：2021年第14卷第9期

页      面：1419-1423页

核心收录：

学科分类：1002[医学-临床医学] 08[工学] 082504[工学-人机与环境工程] 0825[工学-航空宇航科学与技术] 

主　　题：head-down tilt aqueous humor Schlemm’s canal autonomic nervous system intraocular pressure 

摘      要：AIM:To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure(IOP)change following the head-down tilt(HDT)***:The study included 21 participants at the Department of Ophthalmology of Tongji *** received the test of I-care tonometry,enhanced depth imaging optical coherence tomography and heart rate variability(HRV)analysis before and after 15 min HDT *** lumen area of Schlemm’s canal(SCAR),IOP,HRV were ***:IOP increased significantly after 20°head down position from 14.0±3.0 to 17.0±3.3 mm Hg(P0.001).SCAR decreased from 13449.0±5454.9μm^(2) at sitting condition to 9576.6±4130.9μm^(2) post 15 min HDT *** frequency(HF)indices increased significantly from 1462±865 Hz at baseline to 2128±824 *** rate(HR)decreased significantly from 76±11.48 to 70±11.52 bpm after the *** linear regression analysis showed that the difference of HF and SCAR significantly correlated with each other during the HDT(R^(2)=20%,P=0.04).CONCLUSION:These outcomes perform the first evidence of the activation of autonomic nervous system of HDT may cause the collapse of Schlemm’s canal lumen,which in turn leading to the increased IOP.