Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects
AIM: To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure (IOP) change following the head-down tilt (HDT) test. METHODS: The study included 21 participants at the Department of Ophthalmology of Tongji Hospital. Subjects received the test of I-care tono...
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| Format: | Article |
| Language: | English |
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Press of International Journal of Ophthalmology (IJO PRESS)
2021-09-01
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| Series: | International Journal of Ophthalmology |
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| Online Access: | http://ies.ijo.cn/en_publish/2021/9/20210919.pdf |
| _version_ | 1819137994702979072 |
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| author | Wei Chen Zhi-Qi Chen Yan Xiang Chao-Hua Deng Hong Zhang Jun-Ming Wang |
| author_facet | Wei Chen Zhi-Qi Chen Yan Xiang Chao-Hua Deng Hong Zhang Jun-Ming Wang |
| author_sort | Wei Chen |
| collection | DOAJ |
| description | AIM: To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure (IOP) change following the head-down tilt (HDT) test. METHODS: The study included 21 participants at the Department of Ophthalmology of Tongji Hospital. Subjects received the test of I-care tonometry, enhanced depth imaging optical coherence tomography and heart rate variability (HRV) analysis before and after 15min HDT test. The lumen area of Schlemm's canal (SCAR), IOP, HRV were calculated. RESULTS: IOP increased significantly after 20° head down position from 14.0±3.0 to 17.0±3.3 mm Hg (P<0.001). SCAR decreased from 13449.0±5454.9 μm2 at sitting condition to 9576.6±4130.9 μm2 post 15min HDT test. High frequency (HF) indices increased significantly from 1462±865 Hz at baseline to 2128±824 Hz. Heart rate (HR) decreased significantly from 76±11.48 to 70±11.52 bpm after the HDT. The linear regression analysis showed that the difference of HF and SCAR significantly correlated with each other during the HDT (R2=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. |
| first_indexed | 2024-12-22T10:59:43Z |
| format | Article |
| id | doaj.art-a659bb37d7394e9f8e1a2912df86754e |
| institution | Directory Open Access Journal |
| issn | 2222-3959 2227-4898 |
| language | English |
| last_indexed | 2024-12-22T10:59:43Z |
| publishDate | 2021-09-01 |
| publisher | Press of International Journal of Ophthalmology (IJO PRESS) |
| record_format | Article |
| series | International Journal of Ophthalmology |
| spelling | doaj.art-a659bb37d7394e9f8e1a2912df86754e2022-12-21T18:28:32ZengPress of International Journal of Ophthalmology (IJO PRESS)International Journal of Ophthalmology2222-39592227-48982021-09-011491419142310.18240/ijo.2021.09.1920210919Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjectsWei Chen0Zhi-Qi Chen1Yan Xiang2Chao-Hua Deng3Hong Zhang4Jun-Ming Wang5Jun-Ming Wang. Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China. eyedrwjm@163.comDepartment of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, ChinaDepartment of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, ChinaDepartment of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, ChinaDepartment of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, ChinaDepartment of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, ChinaAIM: To evaluate the ocular outcomes and to elucidate possible mechanisms underlying intraocular pressure (IOP) change following the head-down tilt (HDT) test. METHODS: The study included 21 participants at the Department of Ophthalmology of Tongji Hospital. Subjects received the test of I-care tonometry, enhanced depth imaging optical coherence tomography and heart rate variability (HRV) analysis before and after 15min HDT test. The lumen area of Schlemm's canal (SCAR), IOP, HRV were calculated. RESULTS: IOP increased significantly after 20° head down position from 14.0±3.0 to 17.0±3.3 mm Hg (P<0.001). SCAR decreased from 13449.0±5454.9 μm2 at sitting condition to 9576.6±4130.9 μm2 post 15min HDT test. High frequency (HF) indices increased significantly from 1462±865 Hz at baseline to 2128±824 Hz. Heart rate (HR) decreased significantly from 76±11.48 to 70±11.52 bpm after the HDT. The linear regression analysis showed that the difference of HF and SCAR significantly correlated with each other during the HDT (R2=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.http://ies.ijo.cn/en_publish/2021/9/20210919.pdfhead-down tiltaqueous humorschlemm's canalautonomic nervous systemintraocular pressure |
| spellingShingle | Wei Chen Zhi-Qi Chen Yan Xiang Chao-Hua Deng Hong Zhang Jun-Ming Wang Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects International Journal of Ophthalmology head-down tilt aqueous humor schlemm's canal autonomic nervous system intraocular pressure |
| title | Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects |
| title_full | Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects |
| title_fullStr | Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects |
| title_full_unstemmed | Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects |
| title_short | Analogs of microgravity: the function of Schlemm’s canal, intraocular pressure and autonomic nervous during the head-down tilt test in healthy subjects |
| title_sort | analogs of microgravity the function of schlemm s canal intraocular pressure and autonomic nervous during the head down tilt test in healthy subjects |
| topic | head-down tilt aqueous humor schlemm's canal autonomic nervous system intraocular pressure |
| url | http://ies.ijo.cn/en_publish/2021/9/20210919.pdf |
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