PMID- 26920679 OWN - NLM STAT- MEDLINE DCOM- 20170307 LR - 20220330 IS - 1869-1889 (Electronic) IS - 1674-7305 (Linking) VI - 59 IP - 5 DP - 2016 May TI - Pressure balance and imbalance in the optic nerve chamber: The Beijing Intracranial and Intraocular Pressure (iCOP) Study. PG - 495-503 LID - 10.1007/s11427-016-5022-9 [doi] AB - To determine the interdependence of intracranial pressure (ICP) and intraocular pressure (IOP) and how it affects optic nerve pressures, eight normal dogs were examined using pressure-sensing probes implanted into the left ventricle, lumbar cistern, optic nerve subarachnoid space in the left eye, and anterior chamber in the left eye. This allowed ICP, lumbar cistern pressure (LCP), optic nerve subarachnoid space pressure (ONSP) and IOP to be simultaneously recorded. After establishing baseline pressure levels, pressure changes that resulted from lowering ICP (via shunting cerebrospinal fluid (CSF) from the ventricle) were recorded. At baseline, all examined pressures were different (ICP0.001). As ICP was lowered during CSF shunting, IOP also dropped in a parallel time course so that the trans-lamina cribrosa gradient (TLPG) remained stable (ICP-IOP dependent zone). However, once ICP fell below a critical breakpoint, ICP and IOP became uncoupled and TLPG changed as ICP declined (ICP-IOP independent zone). The optic nerve pressure gradient (ONPG) and trans-optic nerve pressure gradient (TOPG) increased linearly as ICP decreased through both the ICP-IOP dependent and independent zones. We conclude that ICP and IOP are coupled in a specific pressure range, but when ICP drops below a critical point, IOP and ICP become uncoupled and TLPG increases. When ICP drops, a rise in the ONPG and TOPG creates more pressure and reduces CSF flow around the optic nerve. This change may play a role in the development and progression of various ophthalmic and neurological diseases, including glaucoma. FAU - Hou, Ruowu AU - Hou R AD - Department of Neurosurgery, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China. FAU - Zhang, Zheng AU - Zhang Z AD - Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, 100730, China. FAU - Yang, Diya AU - Yang D AD - Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, 100730, China. AD - Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China. FAU - Wang, Huaizhou AU - Wang H AD - Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, 100730, China. AD - Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China. FAU - Chen, Weiwei AU - Chen W AD - Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China. FAU - Li, Zhen AU - Li Z AD - Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China. FAU - Sang, Jinghong AU - Sang J AD - Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, 100730, China. FAU - Liu, Sumeng AU - Liu S AD - Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, 100730, China. FAU - Cao, Yiwen AU - Cao Y AD - Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, 100730, China. FAU - Xie, Xiaobin AU - Xie X AD - Department of Ophthalmology, Eye Hospital of China Academy of Chinese Medical Sciences, Beijing, 100040, China. FAU - Ren, Ruojing AU - Ren R AD - Eye center, New York Eye and Ear Infirmary, New York, 10003, USA. FAU - Zhang, Yazhuo AU - Zhang Y AD - Department of Endoscopic and Microinvasive Neurosurgery, Beijing Neurosurgery Institute, Beijing Tiantian Hospital, Capital Medical University, Beijing, 100050, China. zyz2004520@yeah.net. FAU - Sabel, Bernhard A AU - Sabel BA AD - Institute of Medical Psychology, Medical Faculty, Otto-v.-Guericke University of Magdeburg, Magdeburg, 39120, Germany. FAU - Wang, Ningli AU - Wang N AD - Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, 100730, China. wningli@vip.163.com. AD - Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China. wningli@vip.163.com. LA - eng PT - Journal Article DEP - 20160226 PL - China TA - Sci China Life Sci JT - Science China. Life sciences JID - 101529880 SB - IM MH - Humans MH - *Intracranial Pressure MH - *Intraocular Pressure MH - Optic Nerve/*physiology OTO - NOTNLM OT - glaucoma OT - optic nerve pressure gradient (ONPG) OT - optic neuropathy OT - trans-lamina cribrosa pressure gradient (TLPG) OT - trans-optic canal pressure gradient (TCPG) OT - trans-optic nerve pressure gradient (TOPG) EDAT- 2016/02/28 06:00 MHDA- 2017/03/08 06:00 CRDT- 2016/02/28 06:00 PHST- 2015/12/27 00:00 [received] PHST- 2016/01/25 00:00 [accepted] PHST- 2016/02/28 06:00 [entrez] PHST- 2016/02/28 06:00 [pubmed] PHST- 2017/03/08 06:00 [medline] AID - 10.1007/s11427-016-5022-9 [pii] AID - 10.1007/s11427-016-5022-9 [doi] PST - ppublish SO - Sci China Life Sci. 2016 May;59(5):495-503. doi: 10.1007/s11427-016-5022-9. Epub 2016 Feb 26.