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Şenocak MG, Yanmaz LE. Effects of propofol alone or in combination with ketamine on intraocular pressure in unpremedicated dogs. Vet Ophthalmol 2024; 27:139-147. [PMID: 37395174 DOI: 10.1111/vop.13127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 07/04/2023]
Abstract
OBJECTIVE To determine the effects of propofol (P) alone and in combination with ketamine (KP) at ratios of 1:1, 1:2, and 1:3 on intraocular pressure (IOP) in unpremedicated dogs. ANIMALS STUDIED A total of 28 cross-bred healthy dogs. PROCEDURES Dogs were randomly assigned to one of four groups (n = 7 per group) to receive intravenous P or KP at 1:1, 1:2, and 1:3 ratios, respectively. The infusion was administered at 0.6 mg/kg/min for 60 min. IOP, cardiorespiratory variables, rectal temperature (RT), and pedal reflex were recorded every 5 min for 60 min, starting from baseline (BL). RESULTS There was a statistically significant increase in IOP in all groups: P (p = .011), KP 1:1 (p = .003), KP 1:2 (p = .023), and KP 1:3 (p = .008). The IOP increase was less pronounced in the KP 1:2 group and was only significant (p = .023) at T45 compared with BL. A significant correlation was observed between IOP and SpO2 in P (r = -.215, p = .02), KP 1:2 (r = -.579, p < .01), and KP 1:3 (r = -.402, p < .01) groups. IOP significantly increased due to decreased SpO2 below 86.5% (p < .05). CONCLUSIONS Propofol alone and in combination with ketamine may increase preexisting IOP in unpremedicated dogs. SpO2 levels below 86.5% may trigger an increase in IOP. Administering KP in a 1:2 ratio at an infusion rate of 0.6 mg/kg/min does not significantly alter IOP for under 45 min in unpremedicated dogs with sufficient oxygenation.
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Affiliation(s)
- Mümin Gökhan Şenocak
- Department of Surgery, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Latif Emrah Yanmaz
- Department of Surgery, Faculty of Veterinary Medicine, Burdur Mehmet Akif Ersoy University, Burdur, Turkey
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2
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Totou S, Karmiris E, Kanakis M, Gartaganis P, Petrou P, Kalogeropoulos C, Kozobolis V, Stavrakas P. Impact of flight and equivalent short-term high-altitude exposure on ocular structures and function. MEDICAL HYPOTHESIS, DISCOVERY & INNOVATION OPHTHALMOLOGY JOURNAL 2023; 12:127-141. [PMID: 38476577 PMCID: PMC10926315 DOI: 10.51329/mehdiophthal1478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 12/27/2023] [Indexed: 03/14/2024]
Abstract
Background Exposure to high-altitude conditions during flight or similar activities affects many aspects of visual function, which is critical not only for flight safety but for any altitude-related activity. We aimed to summarize the available literature pertaining to ocular changes during flight or equivalent short-term high-altitude exposure (e.g., hypobaric chamber, effortless ascent lasting ≤ 24 h) and to highlight future research priorities. Methods Using the PubMed/MEDLINE and Web of Science/ISI Web of Knowledge databases with structured search syntax, we conducted a systematic review of the literature spanning a 40-year period (January 1, 1983, to October 10, 2023). Articles pertaining to ocular changes during flight or flight-equivalent exposure to altitude were retrieved. The reference lists of retrieved studies were also searched, and citations of these references were included in the results. Results Of 875 relevant PubMed and ISI publications, 122 qualified for inclusion and 20 more were retrieved from the reference lists of initially selected records, for a total of 142 articles. Reported anterior segment changes included deterioration in tear film stability and increased dry eye incidence, increased corneal thickness, discomfort and bubble formation in contact lens users, refraction changes in individuals with prior refractive surgery, decreased intraocular pressure, and alterations in pupillary reaction, contrast sensitivity, and visual fields. Photoreceptor-visual pathway changes included alterations in both photoreceptors and neuro-transduction, as evidenced in dark adaptation, macular recovery time, reduction in visual field sensitivity, and optic neuritis (likely an element of decompression sickness). Retinochoroidal changes included increases in retinal vessel caliber, retinal blood flow, and choroidal thickness; central serous chorioretinopathy; and retinal vascular events (non-arteritic ischemic optic neuropathy, high-altitude retinopathy, and retinal vein occlusion). Conclusions The effect of short-term high-altitude exposure on the eye is, in itself, a difficult area to study. Although serious impairment of visual acuity appears to be rare, ocular changes, including tear film stability, contact lens wear, central corneal thickness, intraocular pressure, contrast sensitivity, stability of refractive surgeries, retinal vessels, visual fields, and macula recovery time, should be considered in civilian aviators. Our report provides guidance to climbers and lowlanders traveling to altitude if they have pre-existing ocular conditions or if they experience visual symptoms while at altitude. However, key outcomes have been contradictory and comprehensive studies are scarce, especially those pertaining to the choroid and retina. Such studies could not only deepen our understanding of high-altitude ocular pathophysiology, but could also offer valuable information and treatment possibilities for a constellation of other vision-threatening diseases.
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Affiliation(s)
- Styliani Totou
- Department of Ophthalmology, University of Patras, School of Medicine, Patras, Greece
- Hellenic Air Force General Hospital, Athens, Attika, Greece
| | | | - Menelaos Kanakis
- Department of Ophthalmology, University of Patras, School of Medicine, Patras, Greece
| | | | - Petros Petrou
- Department of Ophthalmology, National and Kapodistrian University of Athens, School of Medicine, Athens, Greece
| | | | - Vassilios Kozobolis
- Department of Ophthalmology, University of Patras, School of Medicine, Patras, Greece
| | - Panagiotis Stavrakas
- Department of Ophthalmology, University of Patras, School of Medicine, Patras, Greece
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3
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Wang Y, Yu X, Liu Z, Lv Z, Xia H, Wang Y, Li J, Li X. Influence of hypobaric hypoxic conditions on ocular structure and biological function at high attitudes: a narrative review. Front Neurosci 2023; 17:1149664. [PMID: 37229428 PMCID: PMC10203194 DOI: 10.3389/fnins.2023.1149664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 04/04/2023] [Indexed: 05/27/2023] Open
Abstract
Background With the development of science and technology, high-altitude environments, involving aviation, aerospace, and mountainous regions, have become the main areas for human exploration, while such complex environments can lead to rapid decreases in air and oxygen pressure. Although modern aircrafts have pressurized cabins and support equipment that allow passengers and crew to breathe normally, flight crew still face repeated exposure to hypobaric and hypoxic conditions. The eye is a sensory organ of the visual system that responds to light and oxygen plays a key role in the maintenance of normal visual function. Acute hypoxia changes ocular structure and function, such as the blood flow rate, and can cause retinal ischemia. Methods We reviewed researches, and summarized them briefly in a review. Results The acute hypobaric hypoxia affects corneal, anterior chamber angle and depth, pupils, crystal lens, vitreous body, and retina in structure; moreover, the acute hypoxia does obvious effect on visual function; for example, vision, intraocular pressure, oculometric features and dynamic visual performance, visual field, contrast sensitivity, and color perception. Conclusion We summarized the changes in the physiological structure and function of the eye in hypoxic conditions and to provide a biological basis for the response of the human eye at high-altitude.
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Affiliation(s)
- Yuchen Wang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Xinli Yu
- School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Ziyuan Liu
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Zhongsheng Lv
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Huaqin Xia
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yiren Wang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Jiaxi Li
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Xuemin Li
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
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4
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Transcriptomic analysis of the mouse retina after acute and chronic normobaric and hypobaric hypoxia. Sci Rep 2021; 11:16666. [PMID: 34404875 PMCID: PMC8371159 DOI: 10.1038/s41598-021-96150-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/05/2021] [Indexed: 12/13/2022] Open
Abstract
Oxygen delivery to the retinal pigment epithelium and the outer retina is essential for metabolism, function, and survival of photoreceptors. Chronically reduced oxygen supply leads to retinal pathologies in patients and causes age-dependent retinal degeneration in mice. Hypoxia can result from decreased levels of inspired oxygen (normobaric hypoxia) or reduced barometric pressure (hypobaric hypoxia). Since the response of retinal cells to chronic normobaric or hypobaric hypoxia is mostly unknown, we examined the effect of six hypoxic conditions on the retinal transcriptome and photoreceptor morphology. Mice were exposed to short- and long-term normobaric hypoxia at 400 m or hypobaric hypoxia at 3450 m above sea level. Longitudinal studies over 11 weeks in normobaric hypoxia revealed four classes of genes that adapted differentially to the hypoxic condition. Seventeen genes were specifically regulated in hypobaric hypoxia and may affect the structural integrity of the retina, resulting in the shortening of photoreceptor segment length detected in various hypoxic groups. This study shows that retinal cells have the capacity to adapt to long-term hypoxia and that consequences of hypobaric hypoxia differ from those of normobaric hypoxia. Our datasets can be used as references to validate and compare retinal disease models associated with hypoxia.
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5
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Xie Y, Yang Y, Han Y, Yang D, Sun Y, Wang X, Nguyen AH, Chen Y, Tian J, Zhang Q, Xin C, Cao K, Wang H, Liu X, Wang G, Wang N. Association Between Arterial Blood Gas Variation and Intraocular Pressure in Healthy Subjects Exposed to Acute Short-Term Hypobaric Hypoxia. Transl Vis Sci Technol 2019; 8:22. [PMID: 31788351 PMCID: PMC6871546 DOI: 10.1167/tvst.8.6.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/10/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the association between changes in arterial blood gases and intraocular pressure (IOP) after acute, short-term exposure to simulated elevation of 4000 m above sea level. Methods Twenty-five healthy young lowlanders participated in this prospective study. IOP was measured in both eyes with an Accupen tonometer. Arterial blood gas parameters (partial oxygen pressure [PaO2], partial carbon dioxide pressure [PaCO2], pH, and bicarbonate ion [HCO3 -]) were checked using a blood gas analyzer. Measurements were taken at sea level (T1), at 15-minute (T2) and at 2-hour (T3) exposure times to simulated 4000 m above sea level in a hypobaric chamber, and upon return to sea level (T4). Associations between arterial blood gas parameters and IOP were evaluated using multivariate linear regression. Results PaO2 significantly decreased at T2 and T3, resolving at T4 (P < 0.001). pH significantly increased at T2 and returned to baseline at T3 (P = 0.004). Actual and standard bicarbonate ion both dropped with IOP at T3 and T4. IOP significantly decreased from 16.4 ± 3.4 mm Hg at T1 to 15.1 ± 2.1 mm Hg (P = 0.041) at T3 and remained lower (14.9 ± 2.4 mm Hg; P = 0.029) at T4. IOP was not correlated with pH. Multivariate linear regression showed that lower IOP was associated with lower standard bicarbonate ion (beta = -1.061; 95% confidence interval, -0.049 to -2.074; P = 0.04) when adjusted for actual bicarbonate and diastolic blood pressure. Conclusions Hypobaric hypoxia triggers plasma bicarbonate ion reduction which, rather than pH, may decrease aqueous humor formation and subsequently cause IOP reduction. These findings may shed light on the mechanism of IOP regulation at high altitude. Translational Relevance Hypoxia-triggered reduction in plasma bicarbonate ion may decrease aqueous humor production, leading to IOP reduction at high altitude. These findings may provide new insight into a potential mechanism of IOP regulation. Hypobaric hypoxia at high altitude is an environmental factor that can reduce IOP and, therefore, deserves further study.
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Affiliation(s)
- Yuan Xie
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yiquan Yang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ying Han
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Diya Yang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yunxiao Sun
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xinmao Wang
- Department of Pneumology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Anh Hong Nguyen
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Yihan Chen
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jiaxin Tian
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qing Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Chen Xin
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kai Cao
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Huaizhou Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiaofang Liu
- Department of Pneumology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Guozhong Wang
- Department of Hyperbaric and Hypobaric Chamber, Civil Aviation General Hospital, Beijing, China
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China.,Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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6
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Yang Y, Xie Y, Sun Y, Cao K, Li S, Fan S, Huang L, Wu S, Wang N. Intraocular Pressure Changes of Healthy Lowlanders at Different Altitude Levels: A Systematic Review and Meta-Analysis. Front Physiol 2019; 10:1366. [PMID: 31780951 PMCID: PMC6851261 DOI: 10.3389/fphys.2019.01366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 10/14/2019] [Indexed: 11/18/2022] Open
Abstract
Background: High altitude, characterized by hypobaric hypoxia, low temperature, and intensive ultraviolet radiation, is identifiably one of the examples of scientific enquiry into aviation and space analogs. However, little is known about the ocular physiological response, especially intraocular pressure (IOP) changes at high altitude. Objectives: This study aimed to systematically review of high altitude exposure on IOP for healthy lowlanders with unoperated eyes. Methods: A comprehensive systematic literature search was conducted in the electronic databases until September 1st, 2019. A meta-analysis was performed following the preferred reporting items for systematic review and meta-analysis statement (PRISMA). We systematically searched the studies conducted over 2,000 m above sea level (a.s.l) in healthy lowlanders with measurements of IOP. Meta-analyses (random effect model and heterogeneity tests), subgroup analyses (altitude, duration, type, and pattern of exposure), sensitivity analysis, funnel plot, Begger's and Egger's test for publication bias were performed. Quality assessment was conducted using the Newcastle-Ottawa scale. The meta-analysis was registered in the PROSPERO database (CRD42019136865). Results: Of 9595 publications searched, 20 publications (n = 745) qualified for inclusion, with non-significant decrease in overall IOP [standardized mean difference (SMD): 0.14, 95% CI: -0.12-0.40; p = 0.30] with high heterogeneity (p < 0.001, I 2 = 82%). However, subgroup analyses revealed significant decrease of IOP at high altitude of 3,000-5,500 m a.s.l (SMD: 0.57, 95% CI: 0.07-1.06; p = 0.03) whereas increase of IOP at extreme altitude of over 5,500 m a.s.l (SMD: -0.34, 95% CI: -0.61-0.06; p = 0.02). And the duration of exposure more than 72 hours (h) was likely to induce a decrease of IOP bordering on statistical significance at the 5% level (SMD: 1.29, 95% CI: 0.02-2.56; p = 0.05). Simultaneously, we also observed significant decrease of IOP for active exposure (e.g., physical activity and hiking, SMD: 0.81, 95% CI: 0.05-1.57; p = 0.04). Conclusion: Our analysis shows exposure to the altitude over 3,500 m a.s.l, duration of exposure more than 72 h and active exposure pattern may have modest, but significant effects on IOP. The higher altitude, the duration of exposure as well as physical activity seem to play crucial roles in the effects of high-altitude exposure on IOP.
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Affiliation(s)
- Yiquan Yang
- Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital of Capital Medical University, Beijing, China
| | - Yuan Xie
- Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital of Capital Medical University, Beijing, China
| | - Yunxiao Sun
- Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital of Capital Medical University, Beijing, China
| | - Kai Cao
- Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital of Capital Medical University, Beijing, China
| | - Shuning Li
- Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital of Capital Medical University, Beijing, China
| | - Sujie Fan
- Department of Ophthalmology, The Third Hospital of Handan (Handan City Eye Hospital), Handan, China
| | - Lu Huang
- Department of Neurology, The Qinghai Provincial People's Hospital, Xining, China
| | - Shizheng Wu
- Department of Neurology, The Qinghai Provincial People's Hospital, Xining, China
| | - Ningli Wang
- Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital of Capital Medical University, Beijing, China
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7
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Xie Y, Sun YX, Han Y, Yang DY, Yang YQ, Cao K, Li SN, Li X, Lu XX, Wu SZ, Wang NL. Longitudinal observation of intraocular pressure variations with acute altitude changes. World J Clin Cases 2019; 7:3226-3236. [PMID: 31667173 PMCID: PMC6819287 DOI: 10.12998/wjcc.v7.i20.3226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Higher intraocular pressure (IOP) is a major risk factor for developing glaucoma, and the leading cause of irreversible blindness worldwide. High altitude (HA) may be involved in IOP, but the reported results were conflicting. Ascent to HA directly by plane from low altitude regions is an acute, effortless exposure. However, the effects of such exposure to different altitudes on IOP have rarely been reported.
AIM To investigate changes in IOP after rapid effortless exposure to HA in stages and compare it with systemic parameters.
METHODS Fifty-eight healthy subjects (116 eyes) were divided into three groups: 17 low-altitude (LA) residents [44 m above sea level (ASL)], 22 HA residents (2261 m ASL) and 19 very HA (VHA) residents (3750 m ASL). The LA group flew to HA first. Three days later, they flew with the HA group to VHA where both groups stayed for 2 d. Then, the LA group flew back to HA and stayed for 1 d before flying back to 44 m. IOP, oxygen saturation (SpO2) and pulse rate were measured. The linear mixed model was used to compare repeated measurements.
RESULTS IOP in the LA group significantly decreased from 18.41 ± 2.40 mmHg at 44 m to 13.60 ± 3.68 mmHg at 2261 m ASL (P < 0.001), and then to 11.85 ± 2.48 mmHg at 3750 m ASL (P = 0.036 compared to IOP at 2261 m ASL) and partially recovered to 13.47 ± 2.57 mmHg upon return to 44 m. IOP in the LA group at HA and VHA was comparable to that in the local residents (12.2 ± 2.4 mmHg for HA,11.5 ± 1.8 mmHg for VHA). IOP was positively associated with SpO2 while negatively associated with pulse rate.
CONCLUSION IOP in the LA group gradually reduced as altitude elevated in stages and became comparable to IOP in local residents. Hypoxia may be associated with IOP, which deserves further study.
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Affiliation(s)
- Yuan Xie
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100730, China
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
| | - Yun-Xiao Sun
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100730, China
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
| | - Ying Han
- Department of Ophthalmology, University of California, San Francisco, CA 94143, United States
| | - Di-Ya Yang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100730, China
| | - Yi-Quan Yang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100730, China
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
| | - Kai Cao
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
| | - Shu-Ning Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100730, China
| | - Xue Li
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Xin-Xin Lu
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Shi-Zheng Wu
- Departments of Neurology, the Qinghai Provincial People's Hospital, Xining 810007, Qinghai Province, China
| | - Ning-Li Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100730, China
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, China
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8
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Najmanová E, Pluháček F, Botek M, Krejčí J, Jarošová J. Intraocular Pressure Response to Short-Term Extreme Normobaric Hypoxia Exposure. Front Endocrinol (Lausanne) 2018; 9:785. [PMID: 30666235 PMCID: PMC6330315 DOI: 10.3389/fendo.2018.00785] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 12/12/2018] [Indexed: 12/29/2022] Open
Abstract
Purpose: The purpose of the study was to determine the intraocular pressure response to normobaric hypoxia and the consequent recovery under additional well-controlled ambient conditions. Second, the study attempted to determine if the intraocular pressure changes were dependent on its baseline, initial heart rate, sex and arterial oxygen saturation. Methods: Thirty-eight visually healthy volunteers (23 women and 15 men) of an average age 25.2 ± 3.8 years from 49 recruited participants met the inclusion criteria and performed the complete test. Initial intraocular pressure (baseline), heart rate, and arterial oxygen saturation were measured after 7 min of rest under normal ambient conditions at an altitude 250 m above sea level. Each subject then underwent a 10 min normobaric hypoxic exposure and a subsequent 7 min recovery under normoxic conditions. Within hypoxic period, subjects were challenged to breathe hypoxic gas mixture with fraction of inspired oxygen of 9.6% (~6.200 m above sea level). Intraocular pressure and arterial oxygen saturation were re-measured at 4 and 10 min during the hypoxia and at 7 min after hypoxia termination. Results: Intraocular pressure increased in 1.2 mmHg ± 1.9 mmHg and 0.9 mmHg ± 2.3 mmHg at 4 and 10 min during the hypoxic period and returned approximately to the baseline at 7 min of recovery. The influence of sex was not statistically significant. The arterial oxygen saturation decreased in 14.9 ± 4.2% at min 4 and 18.4 ± 5.8% at min 10 during hypoxia and returned to the resting value at 7 min of recovery. The decrease was slightly higher in the case of women if compared with men. The hypoxia induced changes in intraocular pressure were significantly correlated with the arterial oxygen saturation changes, whereas the relationship with intraocular pressure baseline and initial heart rate were insignificant. Conclusion: There was a significant increase in intraocular pressure as a response to short-term normobaric hypoxia, which returned to the baseline in 7 min after hypoxia. The increase was dependent on the induced oxygen desaturation.
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Affiliation(s)
- Eliška Najmanová
- Department of Optics, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - František Pluháček
- Department of Optics, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
- *Correspondence: František Pluháček
| | - Michal Botek
- Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czechia
| | - Jakub Krejčí
- Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czechia
| | - Jana Jarošová
- Department of Optics, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
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9
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Liu HM, Bai CH, Liou CM, Chiou HY, Chen C. Central Corneal Thickness of Healthy Lowlanders at High Altitude: A Systematic Review and Meta-Analysis. Curr Eye Res 2017; 43:460-465. [PMID: 29265942 DOI: 10.1080/02713683.2017.1408127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Central corneal thickness, a marker of corneal hydration and metabolism, was reported to increase at high elevations. This study aimed to assess the effect of chronic high-altitude exposure on the central corneal thickness of healthy lowlanders with unoperated corneas, and determine if a relationship exists between exposure time and corneal edema formation. MATERIALS AND METHODS The PubMed, Embase, Scopus, Cochrane Library, and Airiti Library databases were searched up to 2017 January 31 for prospective cohort studies performed above 2500 m in healthy lowlanders with measurements of the central corneal thickness. Subjects with prior eye surgery, contact lens, and non-hypobaric hypoxic exposure were excluded. RESULTS Seven studies of 207 adults were included. The pooled effect of high-altitude exposure on the central corneal thickness for < 12 hours, 3-5 days, 6-7 days, and > 10 days was a mean difference of 13.4 (95% confidence interval: 5.1-21.6) μm with moderate heterogeneity (p < 0.05, I2 = 59%), 19.3 (95% confidence interval: 9.7-29) μm with low heterogeneity (p = 0.88, I2 = 0%), 20.4 (95% confidence interval: 10.3-30.5) μm with low heterogeneity (p = 0.73, I2 = 0%), and 30.8 (95% confidence interval: 20.4-41.2) μm with low heterogeneity (p = 0.69, I2 = 0%), respectively. Baseline differences between pre-exposure and post-exposure were not statistically significant. Regression analysis revealed a significant linear relation between high-altitude exposure time and corneal edema formation that exceeded 5% after 10 days. CONCLUSIONS High-altitude exposure induces central corneal thickening with significant linear progression over time, whereas it takes over 10 days to reach clinical significance in healthy lowlanders with unoperated corneas, and changes in central corneal thickness are reversible after descent to lower elevations.
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Affiliation(s)
- Hsin-Ming Liu
- a School of Medicine, College of Medicine, Taipei Medical University , Taipei Taiwan
| | - Chyi-Huey Bai
- b Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University , Taipei Taiwan.,c School of Public Health, College of Public Health, Taipei Medical University , Taipei Taiwan
| | - Cher-Ming Liou
- d Department of Anesthesiology, Chung Shan Medical University Hospital , Taichung Taiwan.,e Institute of Medicine, Chung Shan Medical University , Taichung Taiwan
| | - Hung-Yi Chiou
- c School of Public Health, College of Public Health, Taipei Medical University , Taipei Taiwan
| | - Chiehfeng Chen
- b Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University , Taipei Taiwan.,f Division of Plastic Surgery, Department of Surgery, Wan Fang Hospital, Taipei Medical University , Taipei Taiwan.,g Cochrane Taiwan, Taipei Medical University , Taipei Taiwan
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Margo JA, Whiting MF, Brown CH, Hoover CK, Munir WM. The Effect of Chronic Pulmonary Disease and Mechanical Ventilation on Corneal Donor Endothelial Cell Density and Transplant Suitability. Am J Ophthalmol 2017; 183:65-70. [PMID: 28890079 DOI: 10.1016/j.ajo.2017.08.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/25/2017] [Accepted: 08/31/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To determine how chronic obstructive pulmonary disease (COPD) and mechanical ventilation time affect corneal donor endothelial cell density (ECD) and transplant suitability. DESIGN Retrospective cohort study. METHODS Setting: Institutional. STUDY POPULATION Total of 39 679 cornea donor eyes from SightLife Eye Bank between 2012 and 2016. Demographics, death-to-preservation time, ECD, lens status, medical history, time on mechanical ventilation, and suitability for transplantation were included. MAIN OUTCOME MEASURES ECD and transplant suitability. RESULTS Mean ECD was 2733 cells/mm2. Mean age was 59 years. COPD affected 34.2% of donors. Mechanical ventilation was required in 35% of donors. Mean ventilation time was 1.3 days. After controlling for covariates, COPD was not found to be associated with poor transplant suitability (P = .22). Ventilation >7 days was associated with poor transplant suitability (P = .04). Donors with COPD and donors who were mechanically ventilated exhibited lower cell counts (P < .001, P < .01, respectively). Longer ventilation led to reduced endothelial cell density: ventilation time >7 days (-46.5 cells/mm2, P < .001) and >30 days (-101.4 cells/mm2, P = .02). Limitations of the study included the retrospective nature, dataset obtained from a single eye bank, and medical history documentation completed by eye bank technicians. CONCLUSIONS A high proportion of cornea donors have respiratory disease prior to donation. Ventilation time >7 days affected transplant suitability but the presence of COPD did not. Donors with COPD and donors who were mechanically ventilated had reduced cell counts. Longer ventilation times lead to increased cell loss. The presence of respiratory disease may affect tissue oxygenation and endothelial cell health.
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Wang C, Li AL, Pang Y, Lei YQ, Yu L. Changes in intraocular pressure and central corneal thickness during pregnancy: a systematic review and Meta-analysis. Int J Ophthalmol 2017; 10:1573-1579. [PMID: 29062778 DOI: 10.18240/ijo.2017.10.15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 08/10/2017] [Indexed: 01/29/2023] Open
Abstract
AIM To conduct a Meta-analysis for investigating the variations in intraocular pressure (IOP) and central corneal thickness (CCT) during normal pregnancy. METHODS We searched for clinical trials published up to November 2015 without language or region restrictions in PubMed, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, Ovid, EBSCO, Elsevier, the Chinese Biomedicine Database, WanFang, CNKI, CQVIP and Google Scholar. Studies of the ocular changes observed in pregnant women were selected. The main outcomes were assessed by changes in IOP and CCT. RESULTS Fifteen studies were included. In subgroup analyses, IOP was significantly decreased during the second MD=-1.53, 95%CI (-2.19, -0.87); P<0.00001, and third MD=-2.91, 95%CI (-3.74, -2.08); P<0.00001 trimesters of pregnancy. CCT was increased during the second MD=10.12, 95%CI (2.01, 18.22); P=0.01, trimester of pregnancy; moreover, during the third trimester of pregnancy, the CCT displayed an increasing trend, but the difference was not significant MD=5.98, 95%CI (-1.11, 13.07); P=0.1. CONCLUSION A decrease in IOP is accompanied by an increase in CCT in the second and third trimesters of a normal pregnancy in women.
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Affiliation(s)
- Chao Wang
- Department of Ophthalmology, the Affiliated Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
| | - Ai-Ling Li
- Department of the School of Public Health of Southwest Medical University, Luzhou 646000, Sichuan Province, China
| | - Yu Pang
- Department of Ophthalmology, the Affiliated Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
| | - Ying-Qing Lei
- Department of Ophthalmology, the Affiliated Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
| | - Ling Yu
- Department of Ophthalmology, the Affiliated Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
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Willmann G, Schommer K, Schultheiss M, Fischer MD, Bartz-Schmidt KU, Gekeler F, Schatz A. Effect of High Altitude Exposure on Intraocular Pressure Using Goldmann Applanation Tonometry. High Alt Med Biol 2017; 18:114-120. [PMID: 28333563 DOI: 10.1089/ham.2016.0115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Willmann, Gabriel, Kai Schommer, Maximilian Schultheiss, M. Dominik Fischer, Karl-Ulrich Bartz-Schmidt, Florian Gekeler, and Andreas Schatz. Effect of high altitude exposure on intraocular pressure using Goldmann applanation tonometry. High Alt Med Biol. 18:114-120, 2017. AIMS The aim of the study was to quantify changes of intraocular pressure (IOP) during exposure to 4559 m using the state-of-the-art method of Goldmann applanation tonometry for IOP measurement and to detect correlations between IOP and acute mountain sickness (AMS) in a prospective manner. METHODS IOP was measured using a Goldmann applanation tonometer AT 900® (Haag-Streit, Switzerland) and central corneal thickness (CCT) with the anterior segment module of a Spectralis™ HRA+OCT® device (Heidelberg Engineering, Germany) at baseline and high altitude. Assessment of AMS was performed using the Lake Louise and AMS-C questionnaires, and Pearson's correlation coefficient was calculated for association between IOP and AMS. RESULTS Raw IOP values at high altitude were not significantly changed compared to baseline. IOP adjusted to the increase in CCT at high altitude, which is known to alter IOP levels, showed a significant reduction for corrected IOP values on day 3 of exposure (morning -2.1 ± 1.2 mmHg; evening -2.3 ± 1.1 mmHg; p < 0.05). No correlation of IOP with AMS or clinical parameters (heart rate and SpO2) at high altitude was noted. CONCLUSIONS IOP showed a significant reduction of IOP levels when corrected for increased CCT values at high altitude. Furthermore, the prospective measurement of IOP is not useful in diagnosing AMS or for the prediction of more severe high altitude related illnesses as the decrease in IOP and symptoms of AMS do not correlate during altitude exposure.
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Affiliation(s)
- Gabriel Willmann
- 1 Department of Ophthalmology, Katharinenhospital Stuttgart , Stuttgart, Germany .,2 Centre for Ophthalmology, University of Tübingen , Tübingen, Germany
| | - Kai Schommer
- 3 Medizinischer Dienst der Krankenversicherungen , MDK Baden-Württemberg, Mannheim, Germany
| | - Maximilian Schultheiss
- 2 Centre for Ophthalmology, University of Tübingen , Tübingen, Germany .,4 Department of Ophthalmology, University Medical Center Hamburg-Eppendorf (UKE) , Hamburg, Germany
| | - M Dominik Fischer
- 2 Centre for Ophthalmology, University of Tübingen , Tübingen, Germany
| | | | - Florian Gekeler
- 1 Department of Ophthalmology, Katharinenhospital Stuttgart , Stuttgart, Germany .,2 Centre for Ophthalmology, University of Tübingen , Tübingen, Germany
| | - Andreas Schatz
- 1 Department of Ophthalmology, Katharinenhospital Stuttgart , Stuttgart, Germany .,2 Centre for Ophthalmology, University of Tübingen , Tübingen, Germany
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Yilmaz I, Altan C, Aygit ED, Alagoz C, Baz O, Ahmet S, Urvasizoglu S, Yasa D, Demirok A. Comparison of three methods of tonometry in normal subjects: Goldmann applanation tonometer, non-contact airpuff tonometer, and Tono-Pen XL. Clin Ophthalmol 2014; 8:1069-74. [PMID: 24944507 PMCID: PMC4057323 DOI: 10.2147/opth.s6391] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Objective We aimed to compare intraocular pressure (IOP) measurements via three different tonometers: the Goldmann applanation tonometer (GAT), the Tono-Pen® XL (TPXL), and a non-contact airpuff tonometer (NCT). Methods This was a cross-sectional study of 200 eyes from 200 patients. Right eyes of all patients were included in this study. IOP was measured via GAT, NCT, and TPXL by three physicians. Each physician used one of the tonometers. Measurements via the three devices were compared. Results The mean IOP was 15.5±2.2 mmHg (range 10–22) with the GAT, 16.1±3.0 (range 9–25) with the TPXL, and 16.1±2.8 (range 10–26) with the NCT. Bland–Altman analysis showed that the mean difference between measurements from the NCT and the GAT was 0.6±2.3 mmHg. The mean difference between the TPXL and GAT measurements was 0.7±2.5 mmHg. The mean difference between the NCT and TPXL measurements was −0.02±3.0 mmHg. There was no significant difference between the groups according to a one-way analysis of variance (ANOVA) test. P-values were 0.998 for NCT–TPXL, 0.067 for NCT–GAT, and 0.059 for TPXL–GAT. Conclusion The NCT and TPXL provide IOP measurements comparable to those of the gold standard GAT in normotensive eyes.
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Affiliation(s)
- Ihsan Yilmaz
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
| | - Cigdem Altan
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
| | | | - Cengiz Alagoz
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
| | - Okkes Baz
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
| | - Sibel Ahmet
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
| | | | - Dilek Yasa
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
| | - Ahmet Demirok
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
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