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Knier CG, Fleischman D, Hodge DO, Berdahl JP, Fautsch MP. Three-Decade Evaluation of Cerebrospinal Fluid Pressure in Open-Angle Glaucoma at a Tertiary Care Center. J Ophthalmol 2020; 2020:7487329. [PMID: 34527373 PMCID: PMC8437650 DOI: 10.1155/2020/7487329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/28/2020] [Accepted: 10/27/2020] [Indexed: 11/18/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the most prevalent risk factor for primary open-angle glaucoma. However, IOP alone does not fully describe a mechanical basis for disease in patients with normal tension glaucoma or primary open-angle glaucoma. The translaminar pressure difference (TLPD) theory proposes that the pressure gradient generated by the difference of IOP and cerebrospinal fluid pressure (CSFp) acting at the level of the optic nerve can lead to cupping and glaucoma when IOP is higher than normal and/or CSFp is lower than normal. The study results to date have generally supported the TLPD theory; however, varying methods, populations, and sample sizes make it difficult to compare results. To further assess whether there is an association between low CSFp and open-angle glaucoma, 30 years of clinical data that assess 96,543 lumbar punctures were analyzed. Patients with open-angle glaucoma showed a significantly lower CSFp than randomly selected normal control patients (9.9 ± 3 mm·Hg (n = 86) versus 12.1 ± 3.6 mm·Hg (n = 114), p < 0.001) following adjustment for age and sex. This retrospective study provides strong evidence for an association between open-angle glaucoma and low CSFp.
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Affiliation(s)
- Catherine G. Knier
- Mayo Clinic Alix School of Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
- Department of Ophthalmology, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
| | - David Fleischman
- Department of Ophthalmology, University of North Carolina, Chapel Hill, NC, USA
| | - David O. Hodge
- Department of Health Sciences Research, Mayo Clinic and Mayo Foundation, Jacksonville, FL, USA
| | - John P. Berdahl
- Department of Ophthalmology, Vance Thompson Vision, Sioux Falls, SD, USA
| | - Michael P. Fautsch
- Department of Ophthalmology, Mayo Clinic and Mayo Foundation, Rochester, MN, USA
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2
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Ghate D, Kedar S, Havens S, Fan S, Thorell W, Nelson C, Gu L, Tong J, Gulati V. The Effects of Acute Intracranial Pressure Changes on the Episcleral Venous Pressure, Retinal Vein Diameter and Intraocular Pressure in a Pig Model. Curr Eye Res 2020; 46:524-531. [PMID: 32806985 DOI: 10.1080/02713683.2020.1805769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Orbital veins such as the retinal veins and episcleral veins drain into the cavernous sinus, an intracranial venous structure. We studied the effects of acute intracranial pressure (ICP) elevation on episcleral venous pressure, intraocular pressure and retinal vein diameter in an established non-survival pig model. METHODS In six adult female domestic pigs, we increased ICP in 5 mm Hg increments using saline infusion through a lumbar drain. We measured ICP (using parenchymal pressure monitor), intraocular pressure (using pneumatonometer), episcleral venous pressure (using venomanometer), retinal vein diameter (using OCT images) and arterial blood pressure at each stable ICP increment. The average baseline ICP was 5.4 mm Hg (range 1.5-9 mm Hg) and the maximum stable ICP ranged from 18 to 40 mm Hg. Linear mixed models with random intercepts were used to evaluate the effect of acute ICP increase on outcome variables. RESULTS With acute ICP elevation, we found loss of retinal venous pulsation and increased episcleral venous pressure, intraocular pressure and retinal vein pressure in all animals. Specifically, acute ICP increase was significantly associated with episcleral venous pressure (β = 0.31; 95% CI 0.14-0.48, p < .001), intraocular pressure (β = 0.37, 95%CI 0.24-0.50; p < .001) and retinal vein diameter (β = 11.29, 95%CI 1.57-21.00; p = .03) after controlling for the effects of arterial blood pressure. CONCLUSION We believe that the ophthalmic effects of acute ICP elevation are mediated by increased intracranial venous pressure producing upstream pressure changes within the orbital and retinal veins. These results offer exciting possibilities for the development of non-invasive ophthalmic biomarkers to estimate acute ICP elevations following significant neuro-trauma.
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Affiliation(s)
- Deepta Ghate
- Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sachin Kedar
- Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Shane Havens
- Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | - Shan Fan
- Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | - William Thorell
- Department of Neurosurgery, University of Nebraska Medical Center, Omaha, NE, USA
| | - Carl Nelson
- Department of Mechanical Engineering, University of Nebraska, Lincoln, NE, USA
| | - Linxia Gu
- Department of Mechanical Engineering, University of Nebraska, Lincoln, NE, USA.,Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL, USA
| | - Junfei Tong
- Department of Mechanical Engineering, University of Nebraska, Lincoln, NE, USA
| | - Vikas Gulati
- Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, USA
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3
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Andersen MS, Pedersen CB, Poulsen FR. A new novel method for assessing intracranial pressure using non-invasive fundus images: a pilot study. Sci Rep 2020; 10:13062. [PMID: 32747697 PMCID: PMC7400759 DOI: 10.1038/s41598-020-70084-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/25/2020] [Indexed: 12/22/2022] Open
Abstract
Arteriole and venule diameter ratio (A/V-ratio) can be measured using fundus photography. In this pilot study, we correlated changes in the intracranial pressure with the diameter of vessels of the retina. We investigated whether increased intracranial pressure (ICP) was reflected in a measurable and quantifiable distention of the venule diameter, leading to a decreased A/V-ratio. This was demonstrated by assessment of the A/V-ratio in patients already undergoing conventional ICP monitoring with a cerebral intraparenchymal pressure monitor. Our method shows a correlation between A/V ratio and ICP and suggests an easily obtainable and usable point-of-care (POC), non-invasive method to estimate the intracranial pressure without the necessity of mydriatic drugs. Furthermore, the sensitivity/specificity analysis with a cut-off of < 0.8015 A/V-ratio, showed a sensitivity of 94% [85-98%] and a specificity of 50% [34-66%] with a positive likelihood ratio of 9.0. This means that in a clinical setting there is a 94% chance of correctly identifying individuals with ICP ≥ 20 mmHg.
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Affiliation(s)
- Mikkel Schou Andersen
- Department of Neurosurgery, Odense University Hospital, 5000, Odense, Denmark. .,Clinical Institute, University of Southern Denmark, Odense, Denmark. .,BRIDGE (Brain Research - Inter Disciplinary Guided Excellence), University of Southern Denmark, Odense, Denmark.
| | - Christian Bonde Pedersen
- Department of Neurosurgery, Odense University Hospital, 5000, Odense, Denmark.,Clinical Institute, University of Southern Denmark, Odense, Denmark.,BRIDGE (Brain Research - Inter Disciplinary Guided Excellence), University of Southern Denmark, Odense, Denmark
| | - Frantz Rom Poulsen
- Department of Neurosurgery, Odense University Hospital, 5000, Odense, Denmark.,Clinical Institute, University of Southern Denmark, Odense, Denmark.,BRIDGE (Brain Research - Inter Disciplinary Guided Excellence), University of Southern Denmark, Odense, Denmark
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4
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Ficarrotta KR, Passaglia CL. Intracranial pressure modulates aqueous humour dynamics of the eye. J Physiol 2020; 598:403-413. [PMID: 31769030 DOI: 10.1113/jp278768] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/22/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS An elevation in intracranial pressure (ICP) lowers conventional outflow facility (increases aqueous outflow resistance) of rat eyes. The reduction in outflow facility correlates with an increase in intraocular pressure (IOP). The effect of ICP elevation on outflow facility and IOP is blocked by TTX. The results indicate that aqueous humour dynamics is modulated by ICP-driven neural feedback from the brain. This feedback mechanism may act to stabilize translaminar pressure across the optic nerve head and may provide a new avenue for glaucoma therapy. ABSTRACT While intraocular pressure (IOP) is a well-known risk factor for glaucoma, intracranial pressure (ICP) is attracting heightened interest because of its influence on optic nerve head biomechanics. Studies have shown that ICP can have marked impacts on posterior eye health by modifying the translaminar pressure gradient across the optic nerve. There is also growing evidence that IOP and ICP may be interconnected, although the mechanism of their putative interaction is unknown. We sought to test the hypothesis that ICP modulates IOP by altering aqueous humour dynamics. The anterior chamber and lateral ventricle of anaesthetized Brown-Norway rats were cannulated with fine-gauge needles connected to a programmable pump and saline reservoir, respectively. ICP was manipulated by varying reservoir height, and eye outflow facility (C) was determined from the pump flow rate required to hold IOP at different levels. C was 22 ± 4 nl/min/mmHg at resting ICP and 13 ± 3 nl/min/mmHg when ICP was raised 15 mmHg, a reduction of 41 ± 13% (n = 18). The decrease in outflow facility was independent of blood pressure, reversible, scaled with ICP elevation and correlated with increases in resting IOP. It was physiological in origin because C returned to baseline values after the rats were killed and corneal application of TTX though ICP remained elevated. These results indicate that a neural feedback mechanism driven by ICP regulates conventional outflow facility in rats. The mechanism may protect the eye from translaminar pressure swings and may offer a new target for glaucoma treatment.
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Affiliation(s)
- Kayla R Ficarrotta
- Medical Engineering Department, University of South Florida, Tampa, FL, 33620, USA
| | - Christopher L Passaglia
- Medical Engineering Department, University of South Florida, Tampa, FL, 33620, USA.,Ophthalmology Department, University of South Florida, Tampa, FL, 33620, USA
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5
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Tu S, Li K, Ding X, Hu D, Li K, Ge J. Relationship between intraocular pressure and retinal nerve fibre thickness loss in a monkey model of chronic ocular hypertension. Eye (Lond) 2019; 33:1833-1841. [PMID: 31227788 DOI: 10.1038/s41433-019-0484-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 01/31/2019] [Accepted: 04/27/2019] [Indexed: 11/09/2022] Open
Abstract
Chronic ocular hypertension (COHT) monkey models were established by destroying the trabecular meshwork, for investigating the relationship between intraocular pressure (IOP) and retinal nerve fibre layer (RNFL) thickness loss. IOP and RNFL thickness were measured before laser injury and weekly thereafter for 27 weeks using Tono Vet and Stratus optical coherence tomography (OCT). The quantitative relationship was as follows: (1) at 32-47 mmHg, the average damage rate was -3.08 ± 0.28 μm/week; (2) at 25-30 mmHg, it was -1.45 ± 0.19 μm/week. The inferior RNFL and superior RNFL turned out to be the most IOP-sensitive quadrants with the rate of RNFL change almost in parallel with IOP levels. The superior sector seemed to be resistant to high IOP conditions until a RNFL loss of ~20 μm was detected in the inferior sector. The rate of RNFL thickness loss was slowed with obvious turning points at RNFL thicknesses of ~75 μm, 65 μm, and 50 μm. The experimental results have achieved research significance. The COHT Monkey was an ideal animal model that can be used for evaluating the relationship between IOP and RNFL damage. Higher IOP was associated with faster RNFL thickness loss. The level of IOP was a vital factor for RNFL damage rate, and baseline/residual RNFL thickness was also important for subsequent RNFL damage. OCT was suitable for measuring RNFL thickness change in COHT monkey models.
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Affiliation(s)
- Shu Tu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kang Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaohu Ding
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dongpeng Hu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kaijing Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jian Ge
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
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Wang W, Wang M, Li Z, Wang T, Da R. The intraocular pressure could not be used to determine the intracranial pressure in patients with hydrocephalus. Int J Neurosci 2018; 129:42-48. [PMID: 29883235 DOI: 10.1080/00207454.2018.1486832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
PURPOSE An accurate intracranial pressure (ICP) measurement is vital for patients with hydrocephalus. ICP is generally measured by lumbar puncture opening pressure, which is invasive and has potential adverse side effects. Intraocular pressure (IOP) was investigated to measure ICP indirectly; however, its accuracy was controversial. We conducted this retrospective study to investigate whether IOP can be used as a surrogate for ICP in hydrocephalus patients. METHODS We performed a retrospective study enrolled 50 cases, including 32 patients with normal pressure hydrocephalus (NPH) and 18 patients with high pressure hydrocephalus (HPH). The independent factors of ICP, the correlation between ICP and other factors, and diagnostic value of IOP and papilledema to predict ICP were analysed, respectively. RESULTS Patients with HPH were more likely suffered from visual deterioration (33.33% vs. 9.38%, p = .045) and papilledema (55.56% vs. 3.13%, p = .001). Multivariate analysis revealed that papilledema was a significant factor (OR =40.765, 95%CI 3.331-498.846, p = .004). Pearson's correlation analysis indicated that ICP did not correlate with any other factors. CONCLUSIONS IOP was not an independent factor of ICP in patients with hydrocephalus, and could not be used to determine IOP. Papilledema might be a significant factor of ICP in hydrocephalus sufferers. Compared with NPH patients, patients with HPH were more prone to develop papilledema.
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Affiliation(s)
- Wei Wang
- a Department of Neurosurgery , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , People's Republic of China
| | - Maode Wang
- a Department of Neurosurgery , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , People's Republic of China
| | - Zhijin Li
- a Department of Neurosurgery , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , People's Republic of China
| | - Tuo Wang
- a Department of Neurosurgery , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , People's Republic of China
| | - Rong Da
- b Department of Clinical Laboratory , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , People's Republic of China
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7
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Abstract
Assessing intracranial pressure (ICP) remains a cornerstone in neurosurgical care. Invasive techniques for monitoring ICP remain the gold standard. The need for a reliable, safe and reproducible technique to non-invasively assess ICP in the context of early screening and in the neurocritical care environment is obvious. Numerous techniques have been described with several novel advances. While none of the currently available techniques appear independently accurate enough to quantify raised ICP, there is some promising work being undertaken.
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8
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Abstract
Our understanding of the potential role intracranial pressure (ICP) may play in the pathophysiology of glaucoma is evolving. ICP can have a profound effect on the optic nerve; edema of the optic disc is an accepted consequence of elevation in ICP, and optic disc blood flow is known to be affected by ICP. Deformation of the orbit also is a known consequence of aberrations in ICP. Therefore, it is plausible that local alterations in optic nerve structure, blood supply, or axonal transport could result from changes in ICP. This article will summarize the relationship between ICP and the eye, specifically focusing on hypothesized relationships between ICP and glaucoma and the current evidence supporting or refuting ICP as a risk factor for glaucoma.
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9
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McMonnies CW. The interaction between intracranial pressure, intraocular pressure and lamina cribrosal compression in glaucoma. Clin Exp Optom 2016; 99:219-26. [PMID: 27079432 DOI: 10.1111/cxo.12333] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/30/2015] [Accepted: 06/23/2015] [Indexed: 02/03/2023] Open
Abstract
This review examines some of the biomechanical consequences associated with the opposing intraocular and intracranial forces. These forces compress the lamina cribrosa and are a potential source of glaucomatous pathology. A difference between them creates a displacement force on the lamina cribrosa. Increasing intraocular pressure and/or decreasing intracranial pressure will increase the trans-lamina cribrosa pressure difference and the risk of its posterior displacement, canal expansion and the formation of pathological cupping. Both intraocular pressure and intracranial pressure can be elevated during a Valsalva manoeuvre with associated increases in both anterior and posterior lamina cribrosa loading as well as its compression. Any resulting thinning of or damage to the lamina cribrosa and/or retinal ganglion cell axons and/or astrocyte and glial cells attached to the matrix of the lamina cribrosa and/or reduction in blood flow to the lamina cribrosa may contribute to glaucomatous neuropathy. Thinning of the lamina cribrosa reduces its stiffness and increases the risk of its posterior displacement. Optic nerve head posterior displacement warrants medical or surgical lowering of intraocular pressure; however, compared to intraocular pressure, the trans-lamina cribrosa pressure difference may be more important in pressure-related pathology of the optic nerve head region. Similarly important could be increased compression loading of the lamina cribrosa. Reducing participation in activities which elevate intraocular and intracranial pressure will decrease lamina cribrosa compression exposure and may contribute to glaucoma management and may have prognostic significance for glaucoma suspects.
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Affiliation(s)
- Charles W McMonnies
- School of Optometry and Vision Science, University of New South Wales, Kensington, Australia.
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10
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Yavin D, Luu J, James MT, Roberts DJ, Sutherland GR, Jette N, Wiebe S. Diagnostic accuracy of intraocular pressure measurement for the detection of raised intracranial pressure: meta-analysis: a systematic review. J Neurosurg 2014; 121:680-7. [PMID: 24857243 DOI: 10.3171/2014.4.jns13932] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Because clinical examination and imaging may be unreliable indicators of intracranial hypertension, intraocular pressure (IOP) measurement has been proposed as a noninvasive method of diagnosis. The authors conducted a systematic review and meta-analysis to determine the correlation between IOP and intracranial pressure (ICP) and the diagnostic accuracy of IOP measurement for detection of intracranial hypertension. METHODS The authors searched bibliographic databases (Ovid MEDLINE, Ovid EMBASE, and the Cochrane Central Register of Controlled Trials) from 1950 to March 2013, references of included studies, and conference abstracts for studies comparing IOP and invasive ICP measurement. Two independent reviewers screened abstracts, reviewed full-text articles, and extracted data. Correlation coefficients, sensitivity, specificity, and positive and negative likelihood ratios were calculated using DerSimonian and Laird methods and bivariate random effects models. The I(2) statistic was used as a measure of heterogeneity. RESULTS Among 355 identified citations, 12 studies that enrolled 546 patients were included in the meta-analysis. The pooled correlation coefficient between IOP and ICP was 0.44 (95% CI 0.26-0.63, I(2) = 97.7%, p < 0.001). The summary sensitivity and specificity for IOP for diagnosing intracranial hypertension were 81% (95% CI 26%-98%, I(2) = 95.2%, p < 0.01) and 95% (95% CI 43%-100%, I(2) = 97.7%, p < 0.01), respectively. The summary positive and negative likelihood ratios were 14.8 (95% CI 0.5-417.7) and 0.2 (95% CI 0.02-1.7), respectively. When ICP and IOP measurements were taken within 1 hour of another, correlation between the measures improved. CONCLUSIONS Although a modest aggregate correlation was found between IOP and ICP, the pooled diagnostic accuracy suggests that IOP measurement may be of clinical utility in the detection of intracranial hypertension. Given the significant heterogeneity between included studies, further investigation is required prior to the adoption of IOP in the evaluation of intracranial hypertension into routine practice.
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11
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Roe WD, Mayhew IG, Jolly RD, Marshall J, Chilvers BL. Traumatic brain injury, axonal injury and shaking in New Zealand sea lion pups. Vet J 2014; 200:96-102. [PMID: 24565687 DOI: 10.1016/j.tvjl.2014.01.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 01/28/2014] [Accepted: 01/30/2014] [Indexed: 10/25/2022]
Abstract
Trauma is a common cause of death in neonatal New Zealand sea lion pups, and subadult male sea lions have been observed picking up and violently shaking some pups. In humans, axonal injury is a common result of traumatic brain injury, and can be due to direct trauma to axons or to ischaemic damage secondary to trauma. 'Shaken baby syndrome', which has been described in human infants, is characterised by retinal and intracranial subdural haemorrhages, and has been associated with axonal injury to the brain, spinal cord and optic nerve. This study identifies mechanisms of traumatic brain injury in New Zealand sea lion pups, including impact injuries and shaking-type injuries, and identifies gross lesions of head trauma in 22/36 sea lion pups found dead at a breeding site in the Auckland Islands. Despite the high frequency of such gross lesions, only three of the pups had died of traumatic brain injury. Observational studies confirmed that shaking of pups occurred, but none were shown to die as a direct result of these shaking events. Axonal injury was evaluated in all 36 pup brains using β-amyloid precursor protein immunohistochemistry. Immunoreactive axons were present in the brains of all pups examined including seven with vascular axonal injury and two with diffuse axonal injury, but the severity and pattern of injury was not reliably associated with death due to traumatic brain injury. No dead pups had the typical combination of gross lesions and immunohistochemical findings that would conform to descriptions of 'shaken baby syndrome'. Axonal injury was present in the optic nerves of most pups, irrespective of cause of death, but was associated with ischaemia rather than trauma.
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Affiliation(s)
- W D Roe
- Pathobiology Group, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
| | - I G Mayhew
- Veterinary Teaching Hospital, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - R D Jolly
- Pathobiology Group, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - J Marshall
- mEpilab, Infectious Disease Research Centre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - B L Chilvers
- Marine Species and Threats Division, New Zealand Department of Conservation, Wellington, New Zealand
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Golan S, Kurtz S, Mezad-Koursh D, Waisbourd M, Kesler A, Halpern P. Poor correlation between intracranial pressure and intraocular pressure by hand-held tonometry. Clin Ophthalmol 2013; 7:1083-7. [PMID: 23785230 PMCID: PMC3682855 DOI: 10.2147/opth.s38910] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE The aim of this study is to provide data on the controversial issue of whether handheld measurements of intraocular pressure (IOP) are capable of accurately predicting elevated intracranial pressure (ICP) in patients undergoing lumbar puncture (LP). METHODS All patients over the age of 18 years who underwent an LP in the emergency or neurological departments at the Tel Aviv Medical Center for any reason between October 2007 and July 2010 were eligible to participate in this prospective observational pilot study. IOP was measured with the Tono-Pen XL while patients were in the supine position before undergoing LP. ICP was measured in the lateral recumbent position. ICP and bilateral IOP were measured, and the mean and maximum values of IOP were calculated. The association between ICP and each one of the four IOP measures was evaluated by the Pearson correlation coefficient. RESULTS Twenty-four patients (mean age 37.8 ± 15.8 years, ten males and 14 females) were enrolled. The reasons for their requiring an LP were headache (19/24 patients), evaluation for hemiparesis (2/24), cognitive deterioration (1/24), and seizures (2/24). Nine had elevated mean opening pressure (>20 cm H2O), six had an elevated mean IOP (>20 mmHg), and four of these six also had an elevated opening pressure. There was no significant correlation between the ICP measurements and any of the IOP measurements. CONCLUSION Handheld ocular tonometry has poor sensitivity and specificity for the prediction of increased ICP and is not an effective tool for screening for ICP in the ED or in the neurology department.
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Affiliation(s)
- Shani Golan
- Department of Ophthalmology, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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13
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Can Intraocular Pressure Measurements be Used to Screen for Elevated Intracranial Pressure in Emergency Department Patients? J Emerg Med 2012; 43:532-7. [DOI: 10.1016/j.jemermed.2010.04.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 01/06/2010] [Accepted: 04/07/2010] [Indexed: 11/30/2022]
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14
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Li Z, Yang Y, Lu Y, Liu D, Xu E, Jia J, Yang D, Zhang X, Yang H, Ma D, Wang N. Intraocular pressure vs intracranial pressure in disease conditions: a prospective cohort study (Beijing iCOP study). BMC Neurol 2012; 12:66. [PMID: 22862817 PMCID: PMC3444958 DOI: 10.1186/1471-2377-12-66] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 07/13/2012] [Indexed: 02/06/2023] Open
Abstract
Background The correlation between intracranial pressure (ICP) and intraocular pressure (IOP) is still controversial in literature and hence whether IOP can be used as a non-invasive surrogate of ICP remains unknown. The aim of the current study was to further clarify the potential correlation between ICP and IOP. Methods The IOP measured with Goldmann applanation tonometer was carried out on 130 patients whose ICP was determined via lumber puncture. The Pearson correlation coefficient between ICP and IOP was calculated, the fisher line discriminated analysis to evaluate the effectivity of using IOP to predict the ICP level. Results A significant correlation between ICP and IOP was found. ICP was correlated significantly with IOP of the right eyes (p < 0.001) and IOP of the left eyes (p = 0.001) and mean IOP of both eyes (p < 0.001), respectively. However, using IOP as a measurement to predict ICP, the accuracy rate was found to be 65.4%. Conclusion Our data suggested that although a significant correlation exists between ICP and IOP, caution needs to be taken when using IOP readings by Goldmann applanation tonometer as a surrogate for direct cerebrospinal fluid pressure measurement of ICP.
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Affiliation(s)
- Zhen Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
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15
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Kirk T, Jones K, Miller S, Corbett J. Measurement of intraocular and intracranial pressure: Is there a relationship? Ann Neurol 2011; 70:323-6. [DOI: 10.1002/ana.22414] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 02/21/2011] [Accepted: 02/25/2011] [Indexed: 11/07/2022]
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16
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Czarnik T, Gawda R, Kolodziej W, Latka D, Sznajd-Weron K, Weron R. Associations between intracranial pressure, intraocular pressure and mean arterial pressure in patients with traumatic and non-traumatic brain injuries. Injury 2009; 40:33-9. [PMID: 19135194 DOI: 10.1016/j.injury.2008.10.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 10/02/2008] [Accepted: 10/08/2008] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Anatomical proximity of the eye and the intracranial space is a fact but the existence of physiological and pathophysiological relationships between them is elusive. The objective of this study was to explore anatomical and pathophysiological interactions between the eye and the intracranial space and to assess clinical utility of intraocular pressure measurement in estimation of intracranial pressure in patients with brain injuries and to discover how haemodynamic instability could influence these interactions. Controversy surrounds the recent literature concerning this problem and the consensus has not been achieved. MATERIALS AND METHODS We evaluated the correlation between intracranial pressure and intraocular pressure, intracranial pressure and mean arterial pressure, intraocular pressure and mean arterial pressure in 40 patients with brain injuries initially comatose, admitted to our hospital. All patients required the intracranial pressure monitoring on clinical grounds. Simultaneous recordings of intracranial pressure, intraocular pressure and mean arterial pressure were performed. RESULTS We calculated both the linear correlation coefficient and the Spearman rank-order correlation coefficient for all three relations. We found significant correlation between intraocular pressure and mean arterial pressure in 63% of the tested population. When the power of the test was increased, by considering only patients with 11 or more observations, this ratio increased to 76%. However, the correlation between intraocular pressure and intracranial pressure, as well as, between intracranial pressure and mean arterial pressure was not significant. CONCLUSIONS There is no anatomical and pathophysiological basis for the statement that intraocular pressure can be used as an indirect estimator of intracranial pressure.
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Affiliation(s)
- Tomasz Czarnik
- Department of Anaesthesia and Critical Care, Regional Medical Centre, Aleja Witosa 26, 45-418 Opole, Poland.
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Han Y, McCulley TJ, Horton JC. No correlation between intraocular pressure and intracranial pressure. Ann Neurol 2008; 64:221-4. [PMID: 18570302 DOI: 10.1002/ana.21416] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A recent study has reported an excellent correlation between intraocular pressure (IOP) and intracranial pressure (ICP), suggesting that measurement of IOP may serve as a noninvasive means to determine ICP. To reexamine the relation between IOP and ICP, we reviewed the medical records of all patients who underwent lumbar puncture between 1991 and 2007 in the neuro-ophthalmology clinic at the University of California San Francisco. Data for IOP and ICP were available for 55 patients. There was no correlation between IOP and ICP (Pearson correlation coefficient, r = 0.07; p = 0.59). IOP measurement is not a useful substitute for ICP measurement.
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Affiliation(s)
- Ying Han
- Department of Ophthalmology, Beckman Vision Center, University of California San Francisco, San Francisco, CA, USA
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Czarnik T, Gawda R, Latka D, Kolodziej W, Sznajd-Weron K, Weron R. Noninvasive measurement of intracranial pressure: is it possible? ACTA ACUST UNITED AC 2007; 62:207-11. [PMID: 17215756 DOI: 10.1097/01.ta.0000219128.29515.d5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Some publications suggest a strong correlation between the intracranial pressure and the intraocular pressure. Other studies claim no correlation between these two physiologic variables. Our aim was to study whether the tonometry could be a useful method to evaluate intracranial pressure in patients with suspected intracranial abnormality. METHODS We evaluated the correlation between the intracranial pressure and the intraocular pressure, the intracranial pressure and the mean arterial pressure, and the intraocular pressure and the mean arterial pressure in 22 patients, initially comatose, who were admitted to our hospital. All patients required the intracranial pressure monitoring on clinical grounds. Simultaneous measurements were performed and recorded. RESULTS We calculated both the linear correlation coefficient and the Spearman rank-order correlation coefficient. We found significant correlation between the intraocular pressure and the mean arterial pressure in 12 patients; however, significant correlation between the intraocular pressure and the intracranial pressure was found in only 2 patients. CONCLUSION Tonometry is not an appropriate method for the assessment of intracranial pressure increases.
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Affiliation(s)
- Tomasz Czarnik
- Department of Anesthesia and Critical Care, Regional Medical Center, Opole, Poland.
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Volopich S, Mosing M, Auer U, Nell B. Comparison of the effect of hypertonic hydroxyethyl starch and mannitol on the intraocular pressure in healthy normotensive dogs and the effect of hypertonic hydroxyethyl starch on the intraocular pressure in dogs with primary glaucoma. Vet Ophthalmol 2006; 9:239-44. [PMID: 16771759 DOI: 10.1111/j.1463-5224.2006.00467.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE The purpose of this study was to determine if intravenous hypertonic hydroxyethyl starch (7.5%/6%) (HES) could decrease the intraocular pressure (IOP) in healthy normotensive dogs, and compare its effect with that of mannitol (20%) (experimental study). In addition, the potential IOP-lowering effect of hypertonic HES was evaluated in six dogs with primary glaucoma (clinical study). MATERIAL AND METHODS Experimental study: eight male ophthalmoscopically and clinically healthy Beagles were included in this study. The IOP of each dog was measured by applanation tonometry in both eyes to obtain control values at 10:00, 10:15, 10:30, 10:45, 11:00 a.m., and then every hour until 6:00 p.m. prior to the first treatment (control period). Each dog received, with at least 2-week intervals and in a random order, an intravenous (IV) infusion of 4 mL/kg hypertonic HES (1.2 g/kg NaCl; 0.96 g/kg HES) and 4 mL/kg mannitol 20% (1 g/kg) over a period of 15 min starting at 10:00 a.m. IOP was measured oculus uterque (OU) at the same time intervals as in the control study. The differences in IOP between the treatment groups and the baseline IOP (before the start of infusion), between oculus sinister (OS) and oculus dexter (OD) and between the same time points of all groups were determined with a Student's t-test for paired samples (P = 0.05). Clinical study: six dogs with primary glaucoma (representing seven eyes) received an IV infusion of 4 mL/kg hypertonic HES over a period of 15 min. IOP was measured before and 15 and 30 min after starting the infusion. RESULTS Experimental study: no significant difference between IOP of both eyes was found. A significant decrease in IOP from baseline value was recorded at 15, 30, 45, and 60 min after the start of mannitol infusion (mean amplitude in IOP decrease 3.21 mmHg; P < 0.05) and at 15 and 30 min in dogs treated with HES (mean amplitude in IOP decrease 2.43 mmHg; P < 0.05). At 120 and 180 min there was a significantly higher IOP (P < 0.05) in HES treatment group compared to the values of the control group. Clinical study: in 5/7 eyes diagnosed with primary glaucoma a maximum decrease in IOP of an average of 24% from the baseline value (IOP before start of the infusion) was observed (range of decrease 2-21 mmHg). In three of these five cases the maximum decrease was reached at 15 min and in two cases at 30 min. In one case an increase in IOP of 35% (+ 18 mmHg) was seen after 15 min and 26% (+ 13 mmHg) after 30 min. Case 4 showed an increase in IOP of 5% (+ 3 mmHg) after 15 min and a decrease of 6% (- 4 mmHg) after 30 min. CONCLUSIONS Intravenous hypertonic HES is comparable to intravenous mannitol 20% in lowering the intraocular pressure in healthy normotensive dogs. But this effect lasted half an hour longer after mannitol. In 6/7 eyes with primary glaucoma, hypertonic HES decreased IOP.
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Affiliation(s)
- Sabine Volopich
- Department of Surgery and Ophthalmology, University Veterinary Medicine of Vienna, Vienna, Austria.
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Sajjadi SA, Harirchian MH, Sheikhbahaei N, Mohebbi MR, Malekmadani MH, Saberi H. The relation between intracranial and intraocular pressures: study of 50 patients. Ann Neurol 2006; 59:867-70. [PMID: 16634008 DOI: 10.1002/ana.20856] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE We evaluated the correlation between intracranial (ICP) and intraocular pressure (IOP). METHODS Of the 77 patients who underwent a lumbar puncture, 27 were excluded secondary to a history of glaucoma, using drugs effective on IOP, and abnormal funduscopic examination. ICP was measured by lumbar puncture. IOP was measured by two scales of Schiotz tonometer in both eyes, and the mean was calculated. RESULTS We found a significant correlation between ICP and mean IOP (p < 0.001; r = 0.955). Body mass index, age, and disease type had no significant effect on this correlation. INTERPRETATION IOP is correlated with ICP.
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Affiliation(s)
- Seyed A Sajjadi
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Pavlidis M, Stupp T, Georgalas I, Georgiadou E, Moschos M, Thanos S. Intraocular pressure changes during high-altitude acclimatization. Graefes Arch Clin Exp Ophthalmol 2005; 244:298-304. [PMID: 16133013 DOI: 10.1007/s00417-005-1174-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Revised: 02/02/2005] [Accepted: 02/25/2005] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND To evaluate the relationship between hypobaric hypoxia acclimatization and intraocular pressure (IOP) during ascent, acclimatization, and descent between 2286 m and 5050 m. METHODS The following acclimatization-indicative physiological parameters were compared daily with IOP changes in eight healthy climbers of the 2003 Greek Karakorum expedition in altitude stages between 500 m and 5050 m: hemoglobin oxygen saturation (PO2), resting heart rate, blood pressure, retinal findings, and the Lake Louise score for acclimatization grading. RESULTS IOP decreased significantly in the ascent phase (0.58 mmHg/100 m) and recovered (0.71 mmHg/100 m) during acclimatization and descent. A direct proportional correlation between decreases in PO2 and IOP was evaluated. Arterial blood pulse and pressure increased during acclimatization, while IOP decreased. No retinal hemorrhages were observed in well-acclimatized and incompletely acclimatized climbers. CONCLUSIONS Every new active exposure to hypobaric hypoxia in the ascent phase induced a decrease in the IOP parallel to the PO2 decrease and to the level of acclimatization. The results from our study suggest that IOP changes are related to hypoxia-induced respiratory alkalosis and acclimatization stage, which could be used as a simple mobile screening test for acclimatization level to reveal acute mountain sickness and its severe consequences.
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Affiliation(s)
- Mitrofanis Pavlidis
- Department of Experimental Ophthalmology, University Eye Hospital of Münster, Domagkstrasse 15, 48149, Münster, Germany.
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Lashutka MK, Chandra A, Murray HN, Phillips GS, Hiestand BC. The relationship of intraocular pressure to intracranial pressure. Ann Emerg Med 2004; 43:585-91. [PMID: 15111918 DOI: 10.1016/j.annemergmed.2003.12.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
STUDY OBJECTIVE The early detection of intracranial hypertension can lead to timely medical and neurosurgical intervention, preventing brain herniation and death. In this investigation, we hypothesize that an increase in intracranial pressure can be detected by an increase in intraocular pressure using noninvasive existing technology, the handheld tonometer. METHODS This was a prospective observational pilot study conducted at a community hospital. Admitted patients with an invasive intracranial pressure monitor were solicited for participation. Patients were excluded if they had known glaucoma or had sufficient ocular or facial trauma that precluded intraocular pressure determination. Simultaneous measurements of intracranial and intraocular pressure were recorded. RESULTS Twenty-seven patients were enrolled, and 76 individual measurements were performed. All patients with an abnormal intracranial pressure had an abnormal intraocular pressure; similarly, all patients with a normal intracranial pressure had a normal intraocular pressure (sensitivity 1.00, 95% confidence interval 0.86 to 1.0; specificity 1.0, 95% confidence interval 0.93 to 1.0) CONCLUSION Abnormal intraocular pressure as measured with the handheld tonometer is an excellent indicator of abnormal intracranial pressure in patients with known intracranial pathology.
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Affiliation(s)
- Matthew K Lashutka
- Department of Emergency Medicine, The Ohio State University, Columbus, OH, USA
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Hahnenberger RW. Influence of various anesthetic drugs on the intraocular pressure of cats. ALBRECHT VON GRAEFES ARCHIV FUR KLINISCHE UND EXPERIMENTELLE OPHTHALMOLOGIE. ALBRECHT VON GRAEFE'S ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY 1976; 199:179-86. [PMID: 1083696 DOI: 10.1007/bf02385214] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cats with one normal eye and one eye with experimental glaucoma were trained to tolerate tonometry while conscious. They were then given the general anesthetic agents pentobarbital, ketamine, and CI-744 in the lowest and twice the lowest dosages which permitted tonometry in untrained cats. Pentobarbital lowered intraocular pressure (IOP) by 20-50%. Ketamine raised IOP by about 10%. CI-744 had essentially no effect on IOP. The two conpoments of CI-744, tiletamine (CI-634) and zolazepam (CI-716) were given individually in the doses in which they had been given as part of CI-744. Tiletamine had no effect on IOP, while zolazepam lowered IOP by about 10%.
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Abstract
✓ Six cases of bilateral hemorrhage into the vitreous body related to intracranial hypertension are presented. Four were associated with ruptured cerebral aneurysms, and the others followed head injury. The onset of vitreous hemorrhage was delayed in all cases, and in five patients subhyaloid hemorrhages were present from 2 to 27 days prior to their extension into the vitreous. Visual acuity was greatly reduced. The ophthalmoscopic and slit lamp appearance of the vitreous are described. The hemorrhages usually cleared spontaneously within 24 months, and vision returned to normal. Surgical treatment to remove residual vitreous blood in selected cases is outlined.
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