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Lim S, Kim C, Jafari S, Park J, Garcia SS, Demer JL. Postmortem Digital Image Correlation and Finite Element Modeling Demonstrate Posterior Scleral Deformations during Optic Nerve Adduction Tethering. Bioengineering (Basel) 2024; 11:452. [PMID: 38790319 PMCID: PMC11117839 DOI: 10.3390/bioengineering11050452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/25/2024] [Accepted: 04/28/2024] [Indexed: 05/26/2024] Open
Abstract
Postmortem human eyes were subjected to optic nerve (ON) traction in adduction and elevated intraocular pressure (IOP) to investigate scleral surface deformations. We incrementally adducted 11 eyes (age 74.1 ± 9.3 years, standard deviation) from 26° to 32° under normal IOP, during imaging of the posterior globe, for analysis by three-dimensional digital image correlation (3D-DIC). In the same eyes, we performed uniaxial tensile testing in multiple regions of the sclera, ON, and ON sheath. Based on individual measurements, we analyzed eye-specific finite element models (FEMs) simulating adduction and IOP loading. Analysis of 3D-DIC showed that the nasal sclera up to 1 mm from the sheath border was significantly compressed during adduction. IOP elevation from 15 to 30 mmHg induced strains less than did adduction. Tensile testing demonstrated ON sheath stiffening above 3.4% strain, which was incorporated in FEMs of adduction tethering that was quantitatively consistent with changes in scleral deformation from 3D-DIC. Simulated IOP elevation to 30 mmHg did not induce scleral surface strains outside the ON sheath. ON tethering in incremental adduction from 26° to 32° compressed the nasal and stretched the temporal sclera adjacent to the ON sheath, more so than IOP elevation. The effect of ON tethering is influenced by strain stiffening of the ON sheath.
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Affiliation(s)
- Seongjin Lim
- Department of Ophthalmology, Stein Eye Institute, Los Angeles, CA 90095, USA; (S.L.); (S.J.); (J.P.); (S.S.G.)
| | - Changzoo Kim
- Department of Ophthalmology, Kosin University, Busan 49267, Republic of Korea;
| | - Somaye Jafari
- Department of Ophthalmology, Stein Eye Institute, Los Angeles, CA 90095, USA; (S.L.); (S.J.); (J.P.); (S.S.G.)
| | - Joseph Park
- Department of Ophthalmology, Stein Eye Institute, Los Angeles, CA 90095, USA; (S.L.); (S.J.); (J.P.); (S.S.G.)
| | - Stephanie S. Garcia
- Department of Ophthalmology, Stein Eye Institute, Los Angeles, CA 90095, USA; (S.L.); (S.J.); (J.P.); (S.S.G.)
| | - Joseph L. Demer
- Department of Ophthalmology, Stein Eye Institute, Los Angeles, CA 90095, USA; (S.L.); (S.J.); (J.P.); (S.S.G.)
- Neuroscience Interdepartmental Program, University of California, Los Angeles, CA 90095, USA
- Department of Neurology, University of California, Los Angeles, CA 90095, USA
- Department of Bioengineering, University of California, Los Angeles, CA 90095, USA
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Tailor PD, Aul BJ, Sit AJ, Fautsch MP, Chen JJ. Determination of the Trans-Lamina Cribrosa Pressure Difference in a Community-Based Population and its Association with Open-Angle Glaucoma. Ophthalmol Glaucoma 2024; 7:168-176. [PMID: 37783273 PMCID: PMC10960720 DOI: 10.1016/j.ogla.2023.09.002] [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: 07/28/2023] [Revised: 09/13/2023] [Accepted: 09/21/2023] [Indexed: 10/04/2023]
Abstract
PURPOSE To determine the trans-lamina cribrosa pressure difference (TLCPD) in a cohort of normal community-based patients and the relationship to primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). DESIGN Retrospective cohort study of the Mayo Clinic Study of Aging. PARTICIPANTS The Mayo Clinic Study of Aging is a prospective study evaluating the normal aging population. METHODS Mayo Clinic Study of Aging patients who underwent routine lumbar puncture (LP) studies with eye examinations were reviewed. The trans-lamina cribrosa pressure difference was calculated in 2 contexts of intraocular pressure (IOP): (1) maximum IOP at eye visit closest in time to the LP (closest-in-time TLCPD); and (2) IOP before IOP-lowering treatment (pretreatment IOP and pretreatment TLCPD) in POAG and NTG patients. Glaucoma patients without POAG or NTG were excluded. Regression analyses were performed to determine the relationship with glaucoma. MAIN OUTCOME MEASURES IOP, intracranial pressure, TLCPD, POAG, normal-tension glaucoma (NTG) diagnosis, glaucoma parameters. RESULTS Five hundred forty-eight patients were analyzed. Of these, there were 38 treated glaucoma patients (14 POAG and 24 NTG) and 510 nonglaucomatous patients. Cerebral spinal fluid (CSF) opening pressure was 155.0 ± 42.2 mmH2O in nonglaucomatous patients, 144.0 ± 34.0 mmH2O in POAG (P = 0.15 vs. nonglaucomatous patients), and 136.6 ± 29.3 mmH2O in NTG (P = 0.017 vs. nonglaucomatous patients). Intraocular pressure was 15.47 ± 2.9 mmHg in nonglaucomatous patients, 26.6 ± 3.7 mmHg in POAG, and 17.4 ± 3.4 mmHg in NTG. The closest-in-time TLCPD in the nonglaucomatous cohort was 4.07 ± 4.22 mmHg, which was lower than both the POAG cohort (7.19 ± 3.6 mmHg) and the NTG cohort (5.79 ± 4.5 mmHg, P = 0.04). Pretreatment TLCPD for the overall glaucoma cohort was 10.57 ± 6.1 mmHg. The POAG cohort had a higher pretreatment TLCPD (16.05 ± 5.2 mmHg) than the NTG cohort (7.37 ± 4.1 mmHg; P < 0.0001). Closest-in-time TLCPD for the nonglaucoma cohort (4.07± 4.2 mmHg) was significantly lower than pretreatment TLCPDs for both POAG (16.05 ± 5.2 mmHg; P < 0.0001) and NTG (7.37 ± 4.1 mmHg; P < 0.0001) cohorts. CONCLUSIONS This study establishes the baseline TLCPD in a large cohort of normal, community-based patients. The differences in regression analysis between TLCPD and IOP suggests NTG pathophysiology is partially driven by TLCPD, but is also likely multifactorial. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
| | - Bryce J Aul
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota
| | - Arthur J Sit
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota
| | | | - John J Chen
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota; Department of Neurology, Mayo Clinic, Rochester, Minnesota.
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Kristiansen M, Holmlund P, Lindén C, Eklund A, Jóhannesson G. Optic Nerve Subarachnoid Space Posture Dependency - An MRI Study in Subjects With Normal Tension Glaucoma and Healthy Controls. Invest Ophthalmol Vis Sci 2023; 64:20. [PMID: 38099734 PMCID: PMC10729838 DOI: 10.1167/iovs.64.15.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/29/2023] [Indexed: 12/18/2023] Open
Abstract
Purpose The purpose of this study was to examine the differences of optic nerve subarachnoid space (ONSAS) volume in patients with normal tension glaucoma (NTG) and healthy controls in different body positions. Methods Eight patients with NTG and seven healthy controls underwent magnetic resonance imaging (MRI) examinations in head up tilt (HUT) +11 degrees and head down tilt (HDT) -5 degrees positions according to a randomized protocol determining the starting position. The ONSAS volume in both body positions was measured and compared between the two groups. The results were analyzed using a generalized linear model. Results Between HDT and HUT, the postural ONSAS volume change was dependent on starting position (P < 0.001) and group (P = 0.003, NTG versus healthy). A subgroup analysis of those that were randomized to HUT examination first, coming directly from an upright position, showed that the patients with NTG had significantly larger positional ONSAS volume changes compared to the healthy controls; 121 ± 22 µL vs. 65 ± 37 µL (P = 0.049). Analysis of the ONSAS volume distribution showed different profiles for patients with NTG and healthy controls. Conclusions There was a significant difference in ONSAS volume change between patients with NTG and healthy subjects when subjected to posture changes, specifically when going from upright to head-down posture. This indicates that patients with NTG had been exposed to a lower ONSAS pressure when they came from the upright posture, which suggests an increased translaminar pressure difference in upright position. This may support the theory that NTG has a dysfunction in an occlusion mechanism of the optic nerve sheath that could cause abnormally negative ONSAS pressures in upright posture.
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Affiliation(s)
- Martin Kristiansen
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| | - Petter Holmlund
- Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University, Umeå, Sweden
| | - Christina Lindén
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University, Umeå, Sweden
- Umeå Centre for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Gauti Jóhannesson
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden
- Wallenberg Center for Molecular Medicine, Umeå University, Umeå, Sweden
- Department of Ophthalmology, University of Iceland, Reykjavik, Iceland
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Ustick JJ, Pardon LP, Chettry P, Patel NB, Cheng H. Effects of head-down tilt on optic nerve sheath diameter in healthy subjects. Ophthalmic Physiol Opt 2023; 43:1531-1539. [PMID: 37401194 PMCID: PMC10592427 DOI: 10.1111/opo.13200] [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: 02/28/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 07/05/2023]
Abstract
PURPOSE Intracranial pressure increases in head-down tilt (HDT) body posture. This study evaluated the effect of HDT on the optic nerve sheath diameter (ONSD) in normal subjects. METHODS Twenty six healthy adults (age 28 [4.7] years) participated in seated and 6° HDT visits. For each visit, subjects presented at 11:00 h for baseline seated scans and then maintained a seated or 6° HDT posture from 12:00 to 15:00 h. Three horizontal axial and three vertical axial scans were obtained at 11:00, 12:00 and 15:00 h with a 10 MHz ultrasonography probe on the same eye, randomly chosen per subject. At each time point, horizontal and vertical ONSD (mm) were quantified by averaging three measures taken 3 mm behind the globe. RESULTS In the seated visit, ONSDs were similar across time (p > 0.05), with an overall mean (standard deviation) of 4.71 (0.48) horizontally and 5.08 (0.44) vertically. ONSD was larger vertically than horizontally at each time point (p < 0.001). In the HDT visit, ONSD was significantly enlarged from baseline at 12:00 and 15:00 h (p < 0.001 horizontal and p < 0.05 vertical). Mean (standard error) horizontal ONSD change from baseline was 0.37 (0.07) HDT versus 0.10 (0.05) seated at 12:00 h (p = 0.002) and 0.41 (0.09) HDT versus 0.12 (0.06) seated at 15:00 h (p = 0.002); mean vertical ONSD change was 0.14 (0.07) HDT versus -0.07 (0.04) seated at 12:00 h (p = 0.02) and 0.19 (0.06) HDT versus -0.03 (0.04) seated at 15:00 h (p = 0.01). ONSD change in HDT was similar between 12:00 and 15:00 h (p ≥ 0.30). Changes at 12:00 h correlated with those at 15:00 h for horizontal (r = 0.78, p < 0.001) and vertical ONSD (r = 0.73, p < 0.001). CONCLUSION The ONSD increased when body posture transitioned from seated to HDT position without any further change at the end of the 3 h in HDT.
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Affiliation(s)
| | - Laura P. Pardon
- University of Houston, College of Optometry, Houston, Texas, USA
| | - Pratik Chettry
- University of Houston, College of Optometry, Houston, Texas, USA
| | - Nimesh B. Patel
- University of Houston, College of Optometry, Houston, Texas, USA
| | - Han Cheng
- University of Houston, College of Optometry, Houston, Texas, USA
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Lee MS, McCulley TJ, Lee AG, Van Stavern GP. Does Intracranial Pressure Influence the Development of Glaucoma? J Neuroophthalmol 2023; 43:423-429. [PMID: 37166999 DOI: 10.1097/wno.0000000000001857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- Michael S Lee
- Department of Ophthalmology (MSL), University of Minnesota, Minneapolis, Minnesota; Department of Ophthalmology (TJM), University of Texas, Houston, Texas; Department of Ophthalmology (AGL), Houston Methodist, Houston, Texas; and Department of Ophthalmology and Visual Sciences (GPVS), Washington University in St. Louis, St. Louis, Missouri
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Pang R, Lin D, Di X, Liu X, Gao L, Chen J, Jia Y, Cao K, Ren T, Cheng Y, Wang Y, Wang J, Wang N. Reference values for trans-laminar cribrosa pressure difference and its association with systemic biometric factors. Eye (Lond) 2023; 37:2240-2245. [PMID: 36481959 PMCID: PMC10366086 DOI: 10.1038/s41433-022-02323-9] [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: 08/02/2022] [Revised: 10/18/2022] [Accepted: 11/16/2022] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES To provide reference values of trans-laminar cribrosa pressure difference (TLCPD) and reveal the association of TLCPD with systemic biometric factors. METHODS In this cross-sectional study, 526 quasi-healthy subjects (including 776 eyes) who required lumbar puncture for medical reasons were selected from 4915 neurology inpatients from 2019 to 2022. Patients with any diseases affecting intraocular pressure (IOP) or intracranial pressure (ICP) were excluded. The ICPs of all subjects were obtained by lumbar puncture in the left lateral decubitus position. IOP was measured in the seated position by a handheld iCare tonometer prior to lumbar puncture. TLCPD was calculated by subtracting ICP from IOP. Systemic biometric factors were assessed within 1 h prior to TLCPD measurement. RESULTS The TLCPD (mean ± standard deviation) was 4.4 ± 3.6 mmHg, and the 95% reference interval (defined as the 2.5th-97.5th percentiles) of TLCPD was -2.27 to 11.94 mmHg. The 95% reference intervals for IOP and ICP were 10-21 and 6.25-15.44 mmHg, respectively. IOP was correlated with ICP (r = 0.126, p < 0.001). TLCPD was significantly negatively correlated with body mass index (r = -0.086, p = 0.049), whereas it was not associated with age, gender, height, weight, blood pressure, pulse, or waist and hip circumference. CONCLUSIONS This study provides reference values of TLCPD and establishes clinically applicable reference intervals for normal TLCPD. Based on association analysis, TLCPD is higher in people with lower BMI.
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Affiliation(s)
- Ruiqi Pang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Danting Lin
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiaomeng Di
- Department of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xinyu Liu
- Department of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Lehong Gao
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jia Chen
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yu Jia
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Kai Cao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Tianmin Ren
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ying Cheng
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jiawei Wang
- Department of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
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Dattilo M. Noninvasive methods to monitor intracranial pressure. Curr Opin Neurol 2023; 36:1-9. [PMID: 36630209 DOI: 10.1097/wco.0000000000001126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE OF REVIEW Intracranial pressure (ICP) is determined by the production of and outflow facility of cerebrospinal fluid. Since alterations in ICP are implicated in several vision-threatening and life-threatening diseases, measurement of ICP is necessary and common. All current clinical methods to measure ICP are invasive and carry the risk for significant side effects. Therefore, the development of accurate, reliable, objective, and portal noninvasive devices to measure ICP has the potential to change the practice of medicine. This review discusses recent advances and barriers to the clinical implementation of noninvasive devices to determine ICP. RECENT FINDINGS Many noninvasive methods to determine ICP have been developed. Although most have significant limitations limiting their clinical utility, several noninvasive methods have shown strong correlations with invasively obtained ICP and have excellent potential to be developed further to accurately quantify ICP and ICP changes. SUMMARY Although invasive methods remain the mainstay for ICP determination and monitoring, several noninvasive biomarkers have shown promise to quantitatively assess and monitor ICP. With further refinement and advancement of these techniques, it is highly possible that noninvasive methods will become more commonplace and may complement or even supplant invasively obtained methods to determine ICP in certain situations.
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Affiliation(s)
- Michael Dattilo
- Emory Eye Center, Neuro-Ophthalmology Division, Emory University School of Medicine, Atlanta, Georgia, USA
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Zhu Z, Waxman S, Wang B, Wallace J, Schmitt SE, Tyler-Kabara E, Ishikawa H, Schuman JS, Smith MA, Wollstein G, Sigal IA. In vivo Modulation of Intraocular and Intracranial Pressures Causes Nonlinear and Non-monotonic Deformations of the Lamina Cribrosa and Scleral Canal. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.29.526113. [PMID: 36778255 PMCID: PMC9915473 DOI: 10.1101/2023.01.29.526113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Purpose To evaluate changes in monkey optic nerve head (ONH) morphology under acutely controlled intraocular pressure (IOP) and intracranial pressure (ICP). Methods Seven ONHs from six monkeys were imaged via optical coherence tomography while IOP and ICP were maintained at one of 16 conditions. These conditions were defined by 4 levels for each pressure: low, baseline, high and very high. Images were processed to determine scleral canal area, aspect ratio, and planarity and anterior lamina cribrosa (ALC) shape index and curvature. Linear mixed effect models were utilized to investigate the effects of IOP, ICP and their interactions on ONH morphological features. The IOP-ICP interaction model was compared with one based on translaminar pressure difference (TLPD). Results We observed complex, eye-specific, non-linear patterns of ONH morphological changes with changes in IOP and ICP. For all ONH morphological features, linear mixed effects models demonstrated significant interactions between IOP and ICP that were unaccounted for by TLPD. Interactions indicate that the effects of IOP and ICP depend on the other pressure. The IOP-ICP interaction model was a higher quality predictor of ONH features than a TLPD model. Conclusions In vivo modulation of IOP and ICP causes nonlinear and non-monotonic changes in monkey ONH morphology that depend on both pressures and is not accounted for by a simplistic TLPD. These results support and extend prior findings. Translational Relevance A better understanding of ICP's influence on the effects of IOP can help inform the highly variable presentations of glaucoma and effective treatment strategies.
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Affiliation(s)
- Ziyi Zhu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bo Wang
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jacob Wallace
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Samantha E. Schmitt
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Elizabeth Tyler-Kabara
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurosurgery, University of Texas-Austin, Austin, TX, USA
| | - Hiroshi Ishikawa
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Medical Informatics and Clinical Epidemiology (DMICE), Oregon Health & Science University, Portland, OR, USA
| | - Joel S. Schuman
- Department of Ophthalmology, NYU School of Medicine, New York, NY, USA
| | - Matthew A. Smith
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Gadi Wollstein
- Department of Ophthalmology, NYU School of Medicine, New York, NY, USA
| | - Ian A. Sigal
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
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Stoskuviene A, Siaudvytyte L, Januleviciene I, Vaitkus A, Simiene E, Bakstyte V, Ragauskas A, Antman G, Siesky B, Harris A. The Relationship between Intracranial Pressure and Visual Field Zones in Normal-Tension Glaucoma Patients. Diagnostics (Basel) 2023; 13:diagnostics13020174. [PMID: 36672984 PMCID: PMC9857814 DOI: 10.3390/diagnostics13020174] [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: 12/02/2022] [Revised: 12/29/2022] [Accepted: 12/31/2022] [Indexed: 01/05/2023] Open
Abstract
Growing evidence suggests that intracranial pressure (ICP) plays an important role in the pathophysiology of glaucoma, especially in normal-tension glaucoma (NTG) patients. Controversial results exist about ICP’s relationship to visual field (VF) changes. With the aim to assess the relationship between ICP and VF zones in NTG patients, 80 NTG patients (age 59.5 (11.6) years) with early-stage glaucoma were included in this prospective study. Intraocular pressure (IOP) (Goldmann), visual perimetry (Humphrey) and non-invasive ICP (via a two-depth Transcranial Doppler, Vittamed UAB, Lithuania) were evaluated. Translaminar pressure difference (TPD) was calculated according to the formula TPD = IOP − ICP. The VFs of each patient were divided into five zones: nasal, temporal, peripheral, central, and paracentral. The average pattern deviation (PD) scores were calculated in each zone. The level of significance p < 0.05 was considered significant. NTG patients had a mean ICP of 8.5 (2.4) mmHg. Higher TPD was related with lower mean deviation (MD) (p = 0.01) and higher pattern standard deviation (PSD) (p = 0.01). ICP was significantly associated with the lowest averaged PD scores in the nasal VF zone (p < 0.001). There were no significant correlations between ICP and other VF zones with the most negative mean PD value. (p > 0.05). Further studies are needed to analyze the involvement of ICP in NTG management.
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Affiliation(s)
- Akvile Stoskuviene
- Eye Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, 50161 Kaunas, Lithuania
| | - Lina Siaudvytyte
- Eye Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, 50161 Kaunas, Lithuania
| | - Ingrida Januleviciene
- Eye Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, 50161 Kaunas, Lithuania
- Correspondence: ; Tel.: +370-37326760; Fax: +370-37327064
| | - Antanas Vaitkus
- Neurology Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, 50161 Kaunas, Lithuania
| | - Evelina Simiene
- Eye Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, 50161 Kaunas, Lithuania
| | - Viktorija Bakstyte
- Eye Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, 50161 Kaunas, Lithuania
| | - Arminas Ragauskas
- Health Telematics Science Centre of Kaunas University of Technology, Studentu Str. 50, 51368 Kaunas, Lithuania
| | - Gal Antman
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva 49100, Israel
| | - Brent Siesky
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Alon Harris
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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Association between Optic Nerve Sheath Diameter and Lamina Cribrosa Morphology in Normal-Tension Glaucoma. J Clin Med 2023; 12:jcm12010360. [PMID: 36615160 PMCID: PMC9821661 DOI: 10.3390/jcm12010360] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/04/2023] Open
Abstract
(1) Background: To compare optic nerve sheath diameter (ONSD) in normal-tension glaucoma (NTG) and healthy eyes and to investigate the association between ONSD and lamina cribrosa (LC) morphology. (2) Methods: This cross-sectional study included 69 NTG eyes and 69 healthy eyes matched for age, axial length, and intraocular pressure. The LC curvature index (LCCI) was measured from horizontal Cirrus HD-OCT B-scan images from five uniformly divided positions vertically of the optic nerve. The average LCCI was defined as the mean of the measurements at these five locations. ONSD was measured as the width of the optic nerve sheath at the site perpendicular 3 mm behind the posterior globe. LCCI and ONSD were compared in eyes with NTG and healthy eyes. The clinical factors that could affect LCCI were analyzed. (3) Results: NTG eyes had significantly smaller mean ONSD (4.55 ± 0.69 mm vs. 4.97 ± 0.58 mm, p < 0.001) and larger average LCCI (11.61 ± 1.43 vs. 7.58 ± 0.90, p < 0.001) than matched healthy control eyes. LCCI was significantly correlated with smaller ONSD, higher intraocular pressure, thinner global retinal nerve fiber thickness, and worse visual field loss in all subjects (all Ps ≤ 0.022). (4) Conclusions: NTG eyes had smaller ONSD and greater LCCI than healthy control eyes. In addition, a negative correlation was observed between ONSD and LCCI. These findings suggest that cerebrospinal fluid pressure, which ONSD indirectly predicts, may affect LC configuration. Changes in the retrolaminar compartment may play a role in glaucoma pathogenesis.
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Finite element modeling of effects of tissue property variation on human optic nerve tethering during adduction. Sci Rep 2022; 12:18985. [PMID: 36347907 PMCID: PMC9643519 DOI: 10.1038/s41598-022-22899-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 10/20/2022] [Indexed: 11/09/2022] Open
Abstract
Tractional tethering by the optic nerve (ON) on the eye as it rotates towards the midline in adduction is a significant ocular mechanical load and has been suggested as a cause of ON damage induced by repetitive eye movements. We designed an ocular finite element model (FEM) simulating 6° incremental adduction beyond the initial configuration of 26° adduction that is the observed threshold for ON tethering. This FEM permitted sensitivity analysis of ON tethering using observed material property variations in measured hyperelasticity of the anterior, equatorial, posterior, and peripapillary sclera; and the ON and its sheath. The FEM predicted that adduction beyond the initiation of ON tethering concentrates stress and strain on the temporal side of the optic disc and peripapillary sclera, the ON sheath junction with the sclera, and retrolaminar ON neural tissue. However, some unfavorable combinations of tissue properties within the published ranges imposed higher stresses in these regions. With the least favorable combinations of tissue properties, adduction tethering was predicted to stress the ON junction and peripapillary sclera more than extreme conditions of intraocular and intracranial pressure. These simulations support the concept that ON tethering in adduction could induce mechanical stresses that might contribute to ON damage.
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12
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Karimi A, Razaghi R, Rahmati SM, Girkin CA, Downs JC. Relative Contributions of Intraocular and Cerebrospinal Fluid Pressures to the Biomechanics of the Lamina Cribrosa and Laminar Neural Tissues. Invest Ophthalmol Vis Sci 2022; 63:14. [PMID: 36255364 PMCID: PMC9587471 DOI: 10.1167/iovs.63.11.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 09/27/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose The laminar region of the optic nerve head (ONH), thought to be the site of damage to the retinal ganglion cell axons in glaucoma, is continuously loaded on its anterior and posterior surfaces by dynamic intraocular pressure (IOP) and orbital cerebrospinal fluid pressure (CSFP), respectively. Thus, translaminar pressure (TLP; TLP = IOP-CSFP) has been proposed as a glaucoma risk factor. Methods Three eye-specific finite element models of the posterior human eye were constructed, including full 3D microstructures of the load-bearing lamina cribrosa (LC) with interspersed laminar neural tissues (NTs), and heterogeneous, anisotropic, hyperelastic material formulations for the surrounding peripapillary sclera and adjacent pia. ONH biomechanical responses were simulated using three combinations of IOP and CSFP loadings consistent with posture change from sitting to supine. Results Results show that tensile, compressive, and shear stresses and strains in the ONH were higher in the supine position compared to the sitting position (P < 0.05). In addition, LC beams bear three to five times more TLP-driven stress than interspersed laminar NT, whereas laminar NT exhibit three to five times greater strain than supporting LC (P < 0.05). Compared with CSFP, IOP drove approximately four times greater stress and strain in the LC, NT, and peripapillary sclera, normalized per mm Hg pressure change. In addition, IOP drove approximately three-fold greater scleral canal expansion and anterior-posterior laminar deformation than CSFP per mm Hg (P < 0.05). Conclusions Whereas TLP has been hypothesized to play a prominent role in ONH biomechanics, the IOP and CSFP effects are not equivalent, as IOP-driven stress, strain, and deformation play a more dominant role than CSFP effects.
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Affiliation(s)
- Alireza Karimi
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Reza Razaghi
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | | | - Christopher A. Girkin
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - J. Crawford Downs
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States
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13
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Zhang J, Kim K, Kim HJ, Meyer D, Park W, Lee SA, Dai Y, Kim B, Moon H, Shah JV, Harris KE, Collar B, Liu K, Irazoqui P, Lee H, Park SA, Kollbaum PS, Boudouris BW, Lee CH. Smart soft contact lenses for continuous 24-hour monitoring of intraocular pressure in glaucoma care. Nat Commun 2022; 13:5518. [PMID: 36127347 PMCID: PMC9489713 DOI: 10.1038/s41467-022-33254-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 09/09/2022] [Indexed: 11/09/2022] Open
Abstract
Continuous monitoring of intraocular pressure, particularly during sleep, remains a grand challenge in glaucoma care. Here we introduce a class of smart soft contact lenses, enabling the continuous 24-hour monitoring of intraocular pressure, even during sleep. Uniquely, the smart soft contact lenses are built upon various commercial brands of soft contact lenses without altering their intrinsic properties such as lens power, biocompatibility, softness, transparency, wettability, oxygen transmissibility, and overnight wearability. We show that the smart soft contact lenses can seamlessly fit across different corneal curvatures and thicknesses in human eyes and therefore accurately measure absolute intraocular pressure under ambulatory conditions. We perform a comprehensive set of in vivo evaluations in rabbit, dog, and human eyes from normal to hypertension to confirm the superior measurement accuracy, within-subject repeatability, and user comfort of the smart soft contact lenses beyond current wearable ocular tonometers. We envision that the smart soft contact lenses will be effective in glaucoma care.
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Affiliation(s)
- Jinyuan Zhang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Kyunghun Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Ho Joong Kim
- Charles D. Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA
| | - Dawn Meyer
- School of Optometry, Indiana University, Bloomington, IN, USA
| | - Woohyun Park
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Seul Ah Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Yumin Dai
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA
| | - Bongjoong Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.,Department of Mechanical and System Design Engineering, Hongik University, Seoul, 04066, Republic of Korea
| | - Haesoo Moon
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Jay V Shah
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Keely E Harris
- Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN, USA
| | - Brett Collar
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Kangying Liu
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Pedro Irazoqui
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Hyowon Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.,Center for Implantable Devices, Purdue University, West Lafayette, IN, USA.,Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
| | - Shin Ae Park
- Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN, USA.
| | - Pete S Kollbaum
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA. .,School of Optometry, Indiana University, Bloomington, IN, USA.
| | - Bryan W Boudouris
- Charles D. Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA. .,Department of Chemistry, Purdue University, West Lafayette, IN, USA. .,Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA.
| | - Chi Hwan Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA. .,School of Optometry, Indiana University, Bloomington, IN, USA. .,School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA. .,School of Materials Engineering, Purdue University, West Lafayette, IN, USA. .,Center for Implantable Devices, Purdue University, West Lafayette, IN, USA. .,Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA.
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14
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Klarica M, Radoš M, Erceg G, Jurjević I, Petošić A, Virag Z, Orešković D. Cerebrospinal fluid micro-volume changes inside the spinal space affect intracranial pressure in different body positions of animals and phantom. Front Mol Neurosci 2022; 15:931091. [PMID: 36187355 PMCID: PMC9518230 DOI: 10.3389/fnmol.2022.931091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
Interpersonal differences can be observed in the human cerebrospinal fluid pressure (CSFP) in the cranium in an upright body position, varying from positive to subatmospheric values. So far, these changes have been explained by the Monroe–Kellie doctrine according to which CSFP should increase or decrease if a change in at least one of the three intracranial volumes (brain, blood, and CSF) occurs. According to our hypothesis, changes in intracranial CSFP can occur without a change in the volume of intracranial fluids. To test this hypothesis, we alternately added and removed 100 or 200 μl of fluid from the spinal CSF space of four anesthetized cats and from a phantom which, by its dimensions and biophysical characteristics, imitates the cat cerebrospinal system, subsequently comparing CSFP changes in the cranium and spinal space in both horizontal and vertical positions. The phantom was made from a rigid “cranial” part with unchangeable volume, while the “spinal” part was made of elastic material whose modulus of elasticity was in the same order of magnitude as those of spinal dura. When a fluid volume (CSF or artificial CSF) was removed from the spinal space, both lumbar and cranial CSFP pressures decreased by 2.0–2.5 cm H2O for every extracted 100 μL. On the other hand, adding fluid volume to spinal space causes an increase in both lumbar and cranial CSFP pressures of 2.6–3.0 cm H2O for every added 100 μL. Results observed in cats and phantoms did not differ significantly. The presented results on cats and a phantom suggest that changes in the spinal CSF volume significantly affect the intracranial CSFP, but regardless of whether we added or removed the CSF volume, the hydrostatic pressure difference between the measuring sites (lateral ventricle and lumbar subarachnoid space) was always constant. These results suggest that intracranial CSFP can be increased or decreased without significant changes in the volume of intracranial fluids and that intracranial CSFP changes in accordance with the law of fluid mechanics.
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Affiliation(s)
- Marijan Klarica
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- *Correspondence: Marijan Klarica
| | - Milan Radoš
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Gorislav Erceg
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Ivana Jurjević
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Antonio Petošić
- Department of Electroacoustics, Faculty of Electrical Engineering and Computing University of Zagreb, Zagreb, Croatia
| | - Zdravko Virag
- Department of Fluid Mechanics, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
| | - Darko Orešković
- Department of Molecular Biology, Ruder Bošković Institute, Zagreb, Croatia
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15
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Holmlund P, Støverud KH, Eklund A. Mathematical modelling of the CSF system: effects of microstructures and posture on optic nerve subarachnoid space dynamics. Fluids Barriers CNS 2022; 19:67. [PMID: 36042452 PMCID: PMC9426285 DOI: 10.1186/s12987-022-00366-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/18/2022] [Indexed: 11/21/2022] Open
Abstract
Background The pressure difference between the eye and brain in upright postures may be affected by compartmentalization of the optic nerve subarachnoid space (ONSAS). Both pressure and deformation will depend on the microstructures of the ONSAS, and most likely also on ocular glymphatic clearance. Studying these factors could yield important knowledge regarding the translaminar pressure difference, which is suspected to play a role in normal-tension glaucoma. Methods A compartment model coupling the ONSAS with the craniospinal CSF system was used to investigate the effects of microstructures on the pressure transfer through the ONSAS during a posture change from supine to upright body postures. ONSAS distensibility was based on MRI measurements. We also included ocular glymphatic flow to investigate how local pressure gradients alter this flow with changes in posture. Results A compartmentalization of the ONSAS occurred in the upright posture, with ONSAS porosity (degree of microstructural content) affecting the ONSAS pressure (varying the supine/baseline porosity from 1.0 to 0.75 yielded pressures between − 5.3 and − 2 mmHg). Restricting the minimum computed porosity (occurring in upright postures) to 0.3 prevented compartmentalization, and the ONSAS pressure could equilibrate with subarachnoid space pressure (− 6.5 mmHg) in \documentclass[12pt]{minimal}
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\begin{document}$$\le$$\end{document}≤ 1 h. The ocular glymphatics analysis predicted that substantial intraocular-CSF flows could occur without substantial changes in the ONSAS pressure. The flow entering the ONSAS in supine position (both from the intraocular system and from the cranial subarachnoid space) exited the ONSAS through the optic nerve sheath, while in upright postures the flow through the ONSAS was redirected towards the cranial subarachnoid space. Conclusions Microstructures affect pressure transmission along the ONSAS, potentially contributing to ONSAS compartmentalization in upright postures. Different pathways for ocular glymphatic flow were predicted for different postures.
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Affiliation(s)
- Petter Holmlund
- Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University, 901 87, Umeå, Sweden.
| | - Karen-Helene Støverud
- Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University, 901 87, Umeå, Sweden.,Department of Health Research, SINTEF Digital, Trondheim, Norway
| | - Anders Eklund
- Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University, 901 87, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, 901 87, Umeå, Sweden
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16
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Hou M, Shao Z, Zhang S, Liu X, Fan P, Jiang M, Zhao Y, Xiao R, Yuan H. Age-related visual impairments and retinal ganglion cells axonal degeneration in a mouse model harboring OPTN (E50K) mutation. Cell Death Dis 2022; 13:362. [PMID: 35436991 PMCID: PMC9016082 DOI: 10.1038/s41419-022-04836-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/02/2022] [Accepted: 04/05/2022] [Indexed: 11/09/2022]
Abstract
Retinal ganglion cells (RGCs) axons are the signal carriers of visual information between retina and brain. Therefore, they play one of the important roles affected in many optic neurodegenerative diseases like glaucoma. Among the genetic risks associated with glaucoma, the E50K mutation in the Optineurin (OPTN) gene are known to result in glaucoma in the absence of increased intraocular pressure (IOP), whereas the relevant pathological mechanism and neurological issues remain to be further investigated. In this study, the OPTN (E50K) mutant mouse model was established through CRISPR/Cas9-mediated genome editing, and aging-related RGCs loss and the visual dysfunction were identified. In E50K mice 16 months old, the axonal transport decreased comparing to wild-type (WT) mice at the same age. Furthermore, results of electron microscopy demonstrated significant morphological anomaly of mitochondria in RGCs axons of young E50K mice 3 months old, and these changes were aggravated with age. These indicated that the damaged mitochondria-associated dysfunction of RGCs axon should play an etiological role in glaucoma as an age-related outcome of OPTN (E50K) mutation. The findings of this study have potential implications for the targeted prevention and treatment of NTG.
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17
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Abstract
PURPOSE OF REVIEW The purpose of this review is to discuss the contemporary body of literature examining the relationship between cerebrospinal fluid (CSF) and ophthalmic disease. This review focuses on diseases that have a pathogenesis related to the translaminar pressure difference, defined as the pressure difference between the orbital subarachnoid space (OSAS) and the intraocular pressure. The diseases discussed include glaucoma, idiopathic intracranial hypertension, and spaceflight associated neuro-ocular syndrome. RECENT FINDINGS The relationship between cerebrospinal and ophthalmic disease has been investigated for over 100 years. Recent research provides insight into the mechanisms that dictate CSF circulation in the OSAS and how alterations in these mechanism lead to disease. This review discusses these recent findings and their relationship to major ophthalmic diseases. SUMMARY The recent findings provide insight into diseases that have pathogenic mechanisms that are not fully understood. This information will help physicians gain a clearer understanding of the relationship between CSF and ophthalmic disease and guide future research.
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Affiliation(s)
- Richard L Ford
- Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Benjamin J Frankfort
- Departments of Ophthalmology and Neuroscience, Baylor College of Medicine, Houston, Texas, USA
| | - David Fleischman
- Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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18
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Killer HE. Special Cerebral and Cerebrospinal Features in Primary Open Angle Glaucoma and Normal Tension Glaucoma. Klin Monbl Augenheilkd 2022; 239:177-181. [PMID: 35211940 DOI: 10.1055/a-1699-2911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In addition to aqueous humour and blood, cerebrospinal fluid also plays an important part in the pathophysiology of primary open-angle glaucoma (POAG) and, in particular, normal-tension glaucoma (NTG). Apart from the important role of CSF pressure in papillary congestion, the composition of the CSF and its flow rate are relevant. CSF is in contact with the brain, the spinal canal and the optic nerve. In neurodegenerative disease, one potential pathophysiological factor, apart from an altered composition of the CSF, is a decrease in flow rate. Changes in CSF composition and flow rate have also been described in the perioptic subarachnoid space of the optic nerve in patients with normal tension glaucoma. Such findings indicate that primary open angle glaucoma and normal tension glaucoma especially, might be due to a neurodegenerative process.
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19
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Belkin A, Dar N, Pillar S, Tempelhof OF, Barkana Y, Sheiman V, Naftali Ben Haim L, Geffen N. The effect of trabeculectomy and glaucoma drainage device implantation on postural intraocular pressure changes in glaucomatous eyes. Acta Ophthalmol 2021; 99:e1112-e1117. [PMID: 33555632 DOI: 10.1111/aos.14776] [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: 07/02/2020] [Accepted: 01/12/2021] [Indexed: 12/01/2022]
Abstract
PURPOSE To investigate the effect of trabeculectomy and glaucoma drainage device implantation on posture related intraocular pressure (IOP) changes in glaucomatous eyes. METHODS Eyes in this prospective study were divided into three groups: those that underwent Ahmed glaucoma valve implantation (Ahmed group), those that underwent trabeculectomy with mitomycin C (trabeculectomy group) and those treated medically (medication group). IOP was measured in the sitting position, and after 15 min in the left lateral decubitus position using a Tonopen XL, and a Goldmann applanation tonometer (GAT). For GAT measurements in the left lateral decubitus position, we used a specialized system comprised of a motorized bed attached to a modified slit-lamp table. RESULTS 111 eyes of 64 glaucoma patients were included in the analysis: 19 in the Ahmed group, 46 in the trabeculectomy group and 46 in the medication group. The difference in IOP between the sitting and supine positions was significant in the medication (2.23 mmHg) and trabeculectomy (1.48 mmHg) groups, but not in the Ahmed group (0.53 mmHg). This significance was reached with the GAT, but not with the Tonopen. A rise of 5 mmHg or more between the sitting and supine positions was documented in 5.2%, 4.3% and 15.2% of eyes in the Ahmed, trabeculectomy and medication groups, respectively. Intraclass correlation coefficient for IOP measurements in the supine position demonstrated good correlation between the two tonometers. CONCLUSIONS Ahmed valve surgery significantly reduces postural IOP response as compared with medically treated controls. There was no significant difference between Ahmed valve and trabeculectomy in terms of their effect on the postural IOP change.
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Affiliation(s)
- Avner Belkin
- Department of Ophthalmology Meir Medical Center Kfar Saba Israel
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
| | - Nimrod Dar
- Department of Ophthalmology Meir Medical Center Kfar Saba Israel
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
| | - Shani Pillar
- Department of Ophthalmology Meir Medical Center Kfar Saba Israel
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
| | - Ortal F. Tempelhof
- Department of Ophthalmology Tel Aviv Sourasky Medical Center Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | | | | | - Liron Naftali Ben Haim
- Department of Ophthalmology Meir Medical Center Kfar Saba Israel
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
| | - Noa Geffen
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
- Department of Ophthalmology Rabin Medical CenterPetach Tikva Israel
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20
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Yue JL, Zheng SF. Analysis of association between MALAT1 haplotype and the severity of normal-tension glaucoma (NTG). J Cell Mol Med 2021; 25:9918-9926. [PMID: 34599867 PMCID: PMC8572781 DOI: 10.1111/jcmm.15906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/20/2020] [Accepted: 09/02/2020] [Indexed: 12/29/2022] Open
Abstract
MALAT1, which is disorderly expressed in the growth, invasion, migration and cancer cell apoptosis, was shown to be associated with normal-tension glaucoma (NTG), a type of optic neuropathy. The haplotype in MALAT1 affects its expression and is correlated with human diseases like normal-tension glaucoma (NTG). However, the underlying detailed mechanism remains unclear. In this study, we aimed to analyse the association between MALAT1 haplotype and the severity of NTG in a molecular level. Quantitative real-time PCR, ELISA and luciferase assays were performed to establish the underlying signalling pathways. RNFL thickness, RA and C/D ratio were calculated for NTG patients. Accordingly, GGGT haplotype was demonstrated to be associated with a decreased risk of NTG. The MALAT1 level in serum of NTG patients carrying GGGT haplotype was significantly decreased compared with NTG patients carrying other haplotypes, along with elevated miR-1 expression and diminished IL-6 expression. NTG patients carrying GGGT haplotype had thicker RNFL and RA, but a smaller C/D ratio. Sequence analysis found potential target sites of miR-1 on MALAT1 and IL-6, and luciferase assay confirmed the inhibitory effect of miR-1 on MALAT1 and IL-6 expression. Meanwhile, MALAT1 also down-regulated miR-1 expression and consequently up-regulated IL-6 expression. This study presented evidence for a regulatory network containing MALAT1, miR-1 and IL-6, and further demonstrated the effect of MALAT1 haplotype on the risk and severity of NTG.
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Affiliation(s)
- Jin-Liang Yue
- Ophthalmology Department, Zhoukou Central Hospital, Zhoukou, China
| | - Shu-Feng Zheng
- Ophthalmology Department, Eye Hospital, Traditional Chinese Medicine Hospital of Yulin, Yulin, China
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21
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Sobczak M, Asejczyk M, Geniusz M. Does body position, age, and heart rate induce IOP's changes? Eur J Ophthalmol 2021; 32:1530-1537. [PMID: 34096356 DOI: 10.1177/11206721211023313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES The main goal of this research was to determine the differences between the values of intraocular pressure (IOP) in the supine and sitting positions, and to assess the effect of age and cardiovascular parameters. METHODS Seventy-two healthy adults were enrolled and classified into age groups: 20-30 years (group A), 31-40 years (group B), and 41-71 years (group C). Corneal biometry and cardiovascular parameters, such as heart rate (HR), were measured. IOP measurements were taken in the sitting position (IOPS) and in the supine position (IOPL) using the iCare® Pro tonometer. RESULTS A significant difference between the IOPS and IOPL in the entire cohort was found (p < 0.001). Regarding the age subgroups, a significant difference (p < 0.001) between the IOPS and IOPL was obtained in group A (2.6 ± 1.6 mmHg) and group C (1.5 ± 1.3 mmHg). There were no significant differences in the IOPS between groups. The highest IOP values were obtained for group A. The correlations between HR and IOPS are statistically significant for group A and group B, and for HR and IOPL-S for group B only. Multivariate analysis showed that HR has a significant influence on the difference in IOP in the two body positions. CONCLUSION A statistically significant difference between the effect of age and the values of IOPS and IOPL was shown. Cardiovascular parameters showed some relevant statistical dependencies, but with a rather marginal significance in young people. The influence of body position for the measurement of IOP for healthy subjects does not seem to matter, despite the fact that there are some dependencies that are statistically significant.
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Affiliation(s)
- Marcelina Sobczak
- Department of Optics and Photonics, Wroclaw University of Science and Technology, Wrocław, Poland
| | - Magdalena Asejczyk
- Department of Optics and Photonics, Wroclaw University of Science and Technology, Wrocław, Poland
| | - Malwina Geniusz
- Department of Optics and Photonics, Wroclaw University of Science and Technology, Wrocław, Poland
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22
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Li J, Wan C. Non-invasive detection of intracranial pressure related to the optic nerve. Quant Imaging Med Surg 2021; 11:2823-2836. [PMID: 34079745 DOI: 10.21037/qims-20-1188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Intracranial pressure (ICP) is associated with a variety of diseases. Early diagnosis and the timely intervention of elevated ICP are effective means to clinically reduce the morbidity and mortality of some diseases. The detection and judgment of reduced ICP are beneficial to glaucoma doctor and neuro ophthalmologist to diagnose optic nerve disease earlier. It is important to evaluate and monitor ICP clinically. Although invasive ICP detection is the gold standard, it can have complications. Most non-invasive ICP tests are related to the optic nerve and surrounding tissues due to their anatomical characteristics. Ultrasound, magnetic resonance imaging, transcranial Doppler, papilledema on optical coherence tomography, visual evoked potential, ophthalmodynamometry, the assessment of spontaneous retinal venous pulsations, and eye-tracking have potential for application. Although none of these methods can completely replace invasive technology; however, its repeatable, low risk, high accuracy, gradually attracted people's attention. This review summarizes the non-invasive ICP detection methods related to the optic nerve and the role of the diagnosis and prognosis of neurological disorders and glaucoma. We discuss the advantages and challenges and predict possible areas of development in the future.
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Affiliation(s)
- Jian Li
- Department of Radiology, the First Hospital of China Medical University, Shenyang, China
| | - Chao Wan
- Department of Ophthalmology, the First Hospital of China Medical University, Shenyang, China
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23
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Jasien JV, Samuels BC, Johnston JM, Downs JC. Effect of Body Position on Intraocular Pressure (IOP), Intracranial Pressure (ICP), and Translaminar Pressure (TLP) Via Continuous Wireless Telemetry in Nonhuman Primates (NHPs). Invest Ophthalmol Vis Sci 2021; 61:18. [PMID: 33074300 PMCID: PMC7585393 DOI: 10.1167/iovs.61.12.18] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Purpose Recent retrospective clinical studies and animal experiments have suggested that cerebrospinal fluid pressure (CSFP) is important in glaucoma, acting through the translaminar pressure (TLP = IOP − CSFP), which directly affects the optic nerve head. In this study, IOP and intracranial pressure (ICP; a surrogate of CSFP) were measured at various body positions to quantify the determinants of TLP. Methods We have developed an implantable wireless pressure telemetry system based on a small piezoelectric sensor with low temporal drift. Telemetry transducers were placed in the anterior chamber to measure IOP and in the brain parenchyma at eye height to measure ICP. IOP was calibrated against anterior cannulation manometry, and ICP/CSFP was calibrated against an intraparenchymal Codman ICP Express microsensor. We measured IOP, ICP, and TLP = IOP − ICP continuously at 200 Hz in three male nonhuman primates (NHPs) in three trials; pressures were then averaged for 30 seconds per body position. Relative change of IOP, ICP, and TLP from the supine (baseline) position to the seated, standing, and inverted positions were quantified. Results TLP changed significantly and instantaneously from the supine to seated (+14 mm Hg), supine to standing (+13 mm Hg) and supine to inverted (−12 mm Hg) positions (P < 0.05). There was no significant TLP change for supine to prone. ICP showed greater relative change than IOP. Conclusions TLP change due to body position change is driven more by ICP/CSFP than IOP. IOP, ICP, and TLP variability, coupled with telemetry, should allow us to test the hypotheses that IOP, ICP, or TLP fluctuations contribute independently to glaucoma onset or progression.
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Affiliation(s)
- Jessica V Jasien
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - James M Johnston
- Department of Neurosurgery, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - J Crawford Downs
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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24-h intraocular pressure patterns measured by Icare PRO rebound in habitual position of open-angle glaucoma eyes. Graefes Arch Clin Exp Ophthalmol 2021; 259:2327-2335. [PMID: 33914159 DOI: 10.1007/s00417-021-05192-2] [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] [Received: 09/25/2020] [Revised: 03/12/2021] [Accepted: 04/07/2021] [Indexed: 10/21/2022] Open
Abstract
PURPOSE To measure the 24-h intraocular pressure (IOP) by Icare PRO rebound in healthy and primary open-angle glaucoma (POAG) eyes and compare it with non-contact tonometry (NCT). METHODS Thirty POAG patients, who were under IOP-lowering treatment, and 30 healthy subjects were included. Participants were hospitalized overnight for the 24-h IOP measurement. IOPs were measured by Icare PRO and NCT according to a standard protocol every 2 h during 24 h. The 24-h IOP curve and IOP-related parameters were compared between Icare PRO and NCT groups in POAG and healthy eyes. RESULTS The IOPs measured by Icare PRO in habitual position increased notably at 22:00 in the normal group and at 20:00 in the POAG group, reached peak at 0:00, stayed high until 4:00, and then decreased in both groups (all p < 0.05). The POAG patients had higher mean 24-h IOP, peak IOP, IOP fluctuation, and greater IOP change from supine to sitting position in the nocturnal period than those in the normal subjects even after adjusting for eyes, age, gender, CCT, and axial length (all p < 0.05). CONCLUSIONS The Icare PRO provides a well-tolerated approach for 24-h IOP monitoring in habitual position. Twenty-four-hour IOP in habitual position is more sensitive for detecting high nocturnal IOP peaks and greater IOP fluctuation for POAG patients.
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Holmlund P, Støverud KH, Wåhlin A, Wiklund U, Malm J, Jóhannesson G, Eklund A. Posture-Dependent Collapse of the Optic Nerve Subarachnoid Space: A Combined MRI and Modeling Study. Invest Ophthalmol Vis Sci 2021; 62:26. [PMID: 33877263 PMCID: PMC8083083 DOI: 10.1167/iovs.62.4.26] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We hypothesize that a collapse of the optic nerve subarachnoid space (ONSAS) in the upright posture may protect the eyes from large translamina cribrosa pressure differences (TLCPD) believed to play a role in various optic nerve diseases (e.g., glaucoma). In this study, we combined magnetic resonance imaging (MRI) and mathematical modeling to investigate this potential ONSAS collapse and its effects on the TLCPD. Methods First, we performed MRI on six healthy volunteers in 6° head-down tilt (HDT) and 13° head-up tilt (HUT) to assess changes in ONSAS volume (measured from the eye to the optic canal) with changes in posture. The volume change reflects optic nerve sheath (ONS) distensibility. Second, we used the MRI data and mathematical modeling to simulate ONSAS pressure and the potential ONSAS collapse in a 90° upright posture. Results The MRI showed a 33% decrease in ONSAS volume from the HDT to HUT (P < 0.001). In the upright posture, the simulations predicted an ONSAS collapse 25 mm behind lamina cribrosa, disrupting the pressure communication between the ONSAS and the intracranial subarachnoid space. The collapse reduced the simulated postural increase in TLCPD by roughly 1 mm Hg, although this reduction was highly sensitive to ONS distensibility, varying between 0 and 4.8 mm Hg when varying the distensibility by ± 1 SD. Conclusions The ONSAS volume along the optic nerve is posture dependent. The simulations supported the hypothesized ONSAS collapse in the upright posture and showed that even small changes in ONS stiffness/distensibility may affect the TLCPD.
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Affiliation(s)
- Petter Holmlund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | | | - Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Urban Wiklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - Jan Malm
- Department of Clinical Science, Neurosciences, Umeå University, Umeå, Sweden
| | - Gauti Jóhannesson
- Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden.,Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
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Hamarat Y, Bartusis L, Deimantavicius M, Lucinskas P, Siaudvytyte L, Zakelis R, Harris A, Mathew S, Siesky B, Janulevicienė I, Ragauskas A. Can the Treatment of Normal-Pressure Hydrocephalus Induce Normal-Tension Glaucoma? A Narrative Review of a Current Knowledge. ACTA ACUST UNITED AC 2021; 57:medicina57030234. [PMID: 33802375 PMCID: PMC7999145 DOI: 10.3390/medicina57030234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 11/16/2022]
Abstract
Ventriculoperitoneal shunt placement is the most commonly used treatment of normal-pressure hydrocephalus (NPH). It has been hypothesized that normal-tension glaucoma (NTG) is caused by the treatment of NPH by using the shunt to reduce intracranial pressure (ICP). The aim of this study is to review the literature published regarding this hypothesis and to emphasize the need for neuro-ophthalmic follow-up for the concerned patients. The source literature was selected from the results of an online PubMed search, using the keywords "hydrocephalus glaucoma" and "normal-tension glaucoma shunt". One prospective study on adults, one prospective study on children, two retrospective studies on adults and children, two case reports, three review papers including medical hypotheses, and one prospective study on monkeys were identified. Hypothesis about the association between the treatment of NPH using the shunt to reduce ICP and the development of NTG were supported in all reviewed papers. This suggests that a safe lower limit of ICP for neurological patients, especially shunt-treated NPH patients, should be kept. Thus, we proposed to modify the paradigm of safe upper ICP threshold recommended in neurosurgery and neurology into the paradigm of safe ICP corridor applicable in neurology and ophthalmology, especially for shunt-treated hydrocephalic and glaucoma patients.
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Affiliation(s)
- Yasin Hamarat
- Health Telematics Science Institute, Kaunas University of Technology, K. Barsausko Str. 59-A557, LT-51423 Kaunas, Lithuania; (L.B.); (M.D.); (P.L.); (R.Z.); (A.R.)
- Correspondence:
| | - Laimonas Bartusis
- Health Telematics Science Institute, Kaunas University of Technology, K. Barsausko Str. 59-A557, LT-51423 Kaunas, Lithuania; (L.B.); (M.D.); (P.L.); (R.Z.); (A.R.)
| | - Mantas Deimantavicius
- Health Telematics Science Institute, Kaunas University of Technology, K. Barsausko Str. 59-A557, LT-51423 Kaunas, Lithuania; (L.B.); (M.D.); (P.L.); (R.Z.); (A.R.)
| | - Paulius Lucinskas
- Health Telematics Science Institute, Kaunas University of Technology, K. Barsausko Str. 59-A557, LT-51423 Kaunas, Lithuania; (L.B.); (M.D.); (P.L.); (R.Z.); (A.R.)
| | - Lina Siaudvytyte
- Eye Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, LT-50009 Kaunas, Lithuania; (L.S.); (I.J.)
| | - Rolandas Zakelis
- Health Telematics Science Institute, Kaunas University of Technology, K. Barsausko Str. 59-A557, LT-51423 Kaunas, Lithuania; (L.B.); (M.D.); (P.L.); (R.Z.); (A.R.)
| | - Alon Harris
- Glaucoma Research and Diagnostic Center, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.H.); (S.M.); (B.S.)
| | - Sunu Mathew
- Glaucoma Research and Diagnostic Center, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.H.); (S.M.); (B.S.)
| | - Brent Siesky
- Glaucoma Research and Diagnostic Center, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.H.); (S.M.); (B.S.)
| | - Ingrida Janulevicienė
- Eye Clinic, Lithuanian University of Health Sciences, Eiveniu Str. 2, LT-50009 Kaunas, Lithuania; (L.S.); (I.J.)
| | - Arminas Ragauskas
- Health Telematics Science Institute, Kaunas University of Technology, K. Barsausko Str. 59-A557, LT-51423 Kaunas, Lithuania; (L.B.); (M.D.); (P.L.); (R.Z.); (A.R.)
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Mohammadyari P, Gadda G, Taibi A. Modelling physiology of haemodynamic adaptation in short-term microgravity exposure and orthostatic stress on Earth. Sci Rep 2021; 11:4672. [PMID: 33633331 PMCID: PMC7907254 DOI: 10.1038/s41598-021-84197-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/08/2021] [Indexed: 11/09/2022] Open
Abstract
Cardiovascular haemodynamics alters during posture changes and exposure to microgravity. Vascular auto-remodelling observed in subjects living in space environment causes them orthostatic intolerance when they return on Earth. In this study we modelled the human haemodynamics with focus on head and neck exposed to different hydrostatic pressures in supine, upright (head-up tilt), head-down tilt position, and microgravity environment by using a well-developed 1D-0D haemodynamic model. The model consists of two parts that simulates the arterial (1D) and brain-venous (0D) vascular tree. The cardiovascular system is built as a network of hydraulic resistances and capacitances to properly model physiological parameters like total peripheral resistance, and to calculate vascular pressure and the related flow rate at any branch of the tree. The model calculated 30.0 mmHg (30%), 7.1 mmHg (78%), 1.7 mmHg (38%) reduction in mean blood pressure, intracranial pressure and central venous pressure after posture change from supine to upright, respectively. The modelled brain drainage outflow percentage from internal jugular veins is 67% and 26% for supine and upright posture, while for head-down tilt and microgravity is 65% and 72%, respectively. The model confirmed the role of peripheral veins in regional blood redistribution during posture change from supine to upright and microgravity environment as hypothesized in literature. The model is able to reproduce the known haemodynamic effects of hydraulic pressure change and weightlessness. It also provides a virtual laboratory to examine the consequence of a wide range of orthostatic stresses on human haemodynamics.
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Affiliation(s)
- Parvin Mohammadyari
- Department of Physics and Earth Sciences, University of Ferrara, 44122, Ferrara, Italy
| | - Giacomo Gadda
- National Institute for Nuclear Physics (INFN), Section of Ferrara, 44122, Ferrara, Italy.
| | - Angelo Taibi
- Department of Physics and Earth Sciences, University of Ferrara, 44122, Ferrara, Italy
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Eye changes in space : New insights into clinical aspects, pathogenesis, and prevention. Ophthalmologe 2021; 118:96-101. [PMID: 33258060 DOI: 10.1007/s00347-020-01272-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND More than ever research into changes in the eye caused by long-term space flight is becoming the focus of the international and national space agencies National Aeronautics and Space Administration (NASA), European Space Agency (ESA) and German Aerospace Center (DLR). In addition to space radiation-induced cataract formation considerable eye changes, summarized under space flight-associated neuro-ocular syndrome (SANS), can occur. OBJECTIVE This article gives an overview of the current state of research and future directions in the field of research concerned with ocular alterations in SANS and presents the relevance for terrestrial ophthalmological research. MATERIAL AND METHODS An analysis of existing publications on SANS in PubMed and reports on the risk of SANS published by the NASA of the USA was carried out. RESULTS The reasons for the development of the eye changes in space have not been clarified. Factors such as the increase in intracranial pressure, fluid shifts, hypercapnia and genetic factors are the subject of intensive research efforts. A terrestrial model for the induction of papilledema could be established (bed rest studies with -6° head-down tilt as a space analogue). Countermeasures for the development of eye changes, such as intermittent artificial gravity, are the subject of current research studies. CONCLUSION Research into SANS as part of bed rest studies will provide further important insights in the future for space research and also for terrestrial research. Clinical research projects can be derived from space research.
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Deimantavicius M, Hamarat Y, Lucinskas P, Zakelis R, Bartusis L, Siaudvytyte L, Janulevicienė I, Ragauskas A. Prospective Clinical Study of Non-Invasive Intracranial Pressure Measurements in Open-Angle Glaucoma Patients and Healthy Subjects. MEDICINA-LITHUANIA 2020; 56:medicina56120664. [PMID: 33266148 PMCID: PMC7759914 DOI: 10.3390/medicina56120664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/23/2020] [Accepted: 11/27/2020] [Indexed: 11/16/2022]
Abstract
Background and Objective: Glaucoma is a progressive optic neuropathy in which the optic nerve is damaged. The optic nerve is exposed not only to intraocular pressure (IOP) in the eye, but also to intracranial pressure (ICP), as it is surrounded by cerebrospinal fluid in the subarachnoid space. Here, we analyse ICP differences between patients with glaucoma and healthy subjects (HSs). Materials and Methods: Ninety-five patients with normal-tension glaucoma (NTG), 60 patients with high-tension glaucoma (HTG), and 62 HSs were included in the prospective clinical study, and ICP was measured non-invasively by two-depth transcranial Doppler (TCD). Results: The mean ICP of NTG patients (9.42 ± 2.83 mmHg) was significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p = 0.007). The mean ICP of HTG patients (8.11 ± 2.68 mmHg) was significantly lower than that of NTG patients (9.42 ± 2.83 mmHg) (p = 0.008) and significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p < 0.001). Conclusions: An abnormal ICP value could be one of the many influential factors in the optic nerve degeneration of NTG patients and should be considered as such instead of just being regarded as a "low ICP".
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Affiliation(s)
- Mantas Deimantavicius
- Health Telematics Science Institute, Kaunas University of Technology, 51423 Kaunas, Lithuania; (M.D.); (P.L.); (R.Z.); (L.B.); (A.R.)
| | - Yasin Hamarat
- Health Telematics Science Institute, Kaunas University of Technology, 51423 Kaunas, Lithuania; (M.D.); (P.L.); (R.Z.); (L.B.); (A.R.)
- Correspondence: ; Tel.: +370-623-19702
| | - Paulius Lucinskas
- Health Telematics Science Institute, Kaunas University of Technology, 51423 Kaunas, Lithuania; (M.D.); (P.L.); (R.Z.); (L.B.); (A.R.)
| | - Rolandas Zakelis
- Health Telematics Science Institute, Kaunas University of Technology, 51423 Kaunas, Lithuania; (M.D.); (P.L.); (R.Z.); (L.B.); (A.R.)
| | - Laimonas Bartusis
- Health Telematics Science Institute, Kaunas University of Technology, 51423 Kaunas, Lithuania; (M.D.); (P.L.); (R.Z.); (L.B.); (A.R.)
| | - Lina Siaudvytyte
- Eye Clinic, Lithuanian University of Health Sciences, 50161 Kaunas, Lithuania; (L.S.); (I.J.)
| | - Ingrida Janulevicienė
- Eye Clinic, Lithuanian University of Health Sciences, 50161 Kaunas, Lithuania; (L.S.); (I.J.)
| | - Arminas Ragauskas
- Health Telematics Science Institute, Kaunas University of Technology, 51423 Kaunas, Lithuania; (M.D.); (P.L.); (R.Z.); (L.B.); (A.R.)
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Belkin A, Greene RA, Mathew DJ, Trope GE, Jin YP, Gentili F, Buys YM. Postural Changes and the Trans-Lamina Cribrosa Pressure Difference: A Pilot Study in Neurosurgical Patients without Glaucoma. Ophthalmol Glaucoma 2020; 3:269-273. [PMID: 33008559 DOI: 10.1016/j.ogla.2020.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the effect of changes in position in the trans-lamina cribrosa pressure difference (TLCPD) by simultaneously measuring and comparing intracranial pressure (ICP) with intraocular pressure (IOP) in seated and supine positions. DESIGN Prospective cohort study. PARTICIPANTS Patients admitted to the neurosurgery unit at Toronto Western Hospital with an external ventricular drain placed for ICP monitoring. Exclusion criteria were any ophthalmic surgical procedures within the preceding 6 months, history of glaucoma, and corneal abnormalities affecting IOP measurement. METHODS Intraocular pressure and ICP were recorded simultaneously in both the supine and seated positions with the order of positions randomized. Measurements were made 10 minutes after assuming each position. The TLCPD (IOP minus ICP) was calculated for the sitting and supine positions. The paired t test was used to assess significance of differences. MAIN OUTCOME MEASURE The TLCPD. RESULTS Twenty patients were included in the study. The average age was 54±17 years. Results were similar for left and right eyes. Data are shown for right eyes only. Mean sitting and supine IOPs were 15.3±3.5 mmHg and 15.9±3.7 mmHg, respectively (P = 0.32). Mean sitting and supine ICPs were 12.5±6.8 mmHg and 12.8±5.1 mmHg, respectively (P = 0.66). Mean TLCPD was 3.1±6.0 mmHg in the sitting position and 3.1±7.0 mmHg in the supine position (P = 1.00). Supine TLCPD increased in 10 patients (50%), decreased in 8 patients (40%), and was unchanged in 2 patients (10%). CONCLUSIONS In this pilot study of 20 neurosurgical patients without glaucoma, posture-induced TLCPD changes were variable.
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Affiliation(s)
- Avner Belkin
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada.
| | - Rana A Greene
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - David J Mathew
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Graham E Trope
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Ya-Ping Jin
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Fred Gentili
- Department of Surgery, University of Toronto, Toronto, Canada
| | - Yvonne M Buys
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
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Killer HE, Pircher A. What is the optimal glaucoma treatment: reducing aqueous humour production or facilitating its outflow? Eye (Lond) 2020; 34:1719-1721. [PMID: 32415188 PMCID: PMC7608181 DOI: 10.1038/s41433-020-0862-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/24/2020] [Indexed: 12/02/2022] Open
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Jin Y, Wang X, Irnadiastputri SFR, Mohan RE, Aung T, Perera SA, Boote C, Jonas JB, Schmetterer L, Girard MJA. Effect of Changing Heart Rate on the Ocular Pulse and Dynamic Biomechanical Behavior of the Optic Nerve Head. Invest Ophthalmol Vis Sci 2020; 61:27. [PMID: 32315378 PMCID: PMC7401455 DOI: 10.1167/iovs.61.4.27] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose To study the effect of changing heart rate on the ocular pulse and the dynamic biomechanical behavior of the optic nerve head (ONH) using a comprehensive mathematical model. Methods In a finite element model of a healthy eye, a biphasic choroid consisted of a solid phase with connective tissues and a fluid phase with blood, and the lamina cribrosa (LC) was viscoelastic as characterized by a stress-relaxation test. We applied arterial pressures at 18 ocular entry sites (posterior ciliary arteries), and venous pressures at four exit sites (vortex veins). In the model, the heart rate was varied from 60 to 120 bpm (increment: 20 bpm). We assessed the ocular pulse amplitude (OPA), pulse volume, ONH deformations, and the dynamic modulus of the LC at different heart rates. Results With an increasing heart rate, the OPA decreased by 0.04 mm Hg for every 10 bpm increase in heart rate. The ocular pulse volume decreased linearly by 0.13 µL for every 10 bpm increase in heart rate. The storage modulus and the loss modulus of the LC increased by 0.014 and 0.04 MPa, respectively, for every 10 bpm increase in heart rate. Conclusions In our model, the OPA, pulse volume, and ONH deformations decreased with an increasing heart rate, whereas the LC became stiffer. The effects of blood pressure/heart rate changes on ONH stiffening may be of interest for glaucoma pathology.
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Wåhlin A, Holmlund P, Fellows AM, Malm J, Buckey JC, Eklund A. Optic Nerve Length before and after Spaceflight. Ophthalmology 2020; 128:309-316. [PMID: 32659310 DOI: 10.1016/j.ophtha.2020.07.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 10/23/2022] Open
Abstract
PURPOSE The spaceflight-associated neuro-ocular syndrome (SANS) affects astronauts on missions to the International Space Station (ISS). The SANS has blurred vision and ocular changes as typical features. The objective of this study was to investigate if microgravity can create deformations or movements of the eye or optic nerve, and if such changes could be linked to SANS. DESIGN Cohort study. PARTICIPANTS Twenty-two astronauts (age 48 ± 4 years). METHODS The intervention consisted of time in microgravity at the ISS. We co-registered pre- and postspaceflight magnetic resonance imaging (MRI) scans and generated centerline representations of the optic nerve. The coordinates for the optic nerve head (ONH) and optic chiasm (OC) ends of the optic nerve were recorded along with the entire centerline path. MAIN OUTCOME MEASURES Optic nerve length, ONH movement, and OC movement after time in microgravity. RESULTS Optic nerve length increased (0.80 ± 0.74 mm, P < 0.001), primarily reflecting forward ONH displacement (0.63 ± 0.53 mm, P < 0.001). The forward displacement was positively related to mission duration, preflight body weight, and clinical manifestations of SANS. We also detected upward displacement of the OC (0.39 ± 0.50 mm, P = 0.002), indicative of brain movement, but this observation could not be linked to SANS. CONCLUSIONS The spaceflight-induced optic nerve lengthening and anterior movement of the ONH support that SANS is caused by an altered pressure difference between the brain and the eye, leading to a forward push on the posterior of the eye. Body weight is a potential contributing risk factor. Direct assessment of intracranial pressure in space is required to verify the implicated mechanism behind the ocular findings in SANS.
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Affiliation(s)
- Anders Wåhlin
- Department of Radiation Sciences, Umeå University, Umeå, Sweden; Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden
| | - Petter Holmlund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | | | - Jan Malm
- Department of Clinical Science, Umeå University, Umeå, Sweden
| | - Jay C Buckey
- Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden; Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden.
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Lee C, Rohr J, Sass A, Sater S, Zahid A, Macias B, Stenger MB, Samuels BC, Martin BA, Oshinski JN, Ethier CR. In vivo estimation of optic nerve sheath stiffness using noninvasive MRI measurements and finite element modeling. J Mech Behav Biomed Mater 2020; 110:103924. [PMID: 32957219 DOI: 10.1016/j.jmbbm.2020.103924] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 12/21/2022]
Abstract
The optic nerve sheath (ONS) is biomechanically important. It is acted on by tension due to ocular movements, and by fluid shifts and/or alterations in intracranial pressure (ICP) in human disease, specifically in pathologies leading to intracranial hypertension. It has also been hypothesized that the ONS is acted on by altered ICP in astronauts exposed chronically to microgravity. However, a non-invasive method to quantify ONS biomechanical properties is not presently available; knowledge of such properties is desirable to allow characterization of the biomechanical forces exerted on the optic nerve head and other ocular structures due to the ONS. Thus, the primary objective of this study was to characterize the biomechanical properties (stiffness) of the human ONS in vivo as a necessary step towards investigating the role of ICP in various conditions, including Spaceflight Associated Neuro-ocular Syndrome (SANS). We acquired non-invasive magnetic resonance imaging (MRI) scans of ostensibly healthy subjects (n = 18, age = 30.4 ± 11.6 [mean ± SD] years) during supine and 15-degree head-down-tilt (HDT) postures, and extracted ONS contours from these scans. We then used finite element modeling to quantify ONS expansion due to postural changes and an inverse approach to estimate ONS stiffness. Using this non-invasive procedure, we estimated an in vivo ONS stiffness of 39.2 ± 21.9 kPa (mean ± SD), although a small subset of individuals had very stiff ONS that precluded accurate estimates of their stiffness values. ONS stiffness was not correlated with age and was higher in males than females.
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Affiliation(s)
- Chanyoung Lee
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Jesse Rohr
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Austin Sass
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Stuart Sater
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - Arslan Zahid
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Brandon Macias
- Cardiovascular and Vision Laboratory, KBR, Houston, TX, USA
| | | | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Bryn A Martin
- Department of Biological Engineering, University of Idaho, Moscow, ID, USA
| | - John N Oshinski
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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35
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Loiselle AR, de Kleine E, van Dijk P, Jansonius NM. Intraocular and intracranial pressure in glaucoma patients taking acetazolamide. PLoS One 2020; 15:e0234690. [PMID: 32555666 PMCID: PMC7302490 DOI: 10.1371/journal.pone.0234690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/30/2020] [Indexed: 11/18/2022] Open
Abstract
The alternative mechanical theory of glaucoma, in which an increased pressure difference across the lamina cribrosa (difference between intraocular and intracranial pressure; IOP and ICP), rather than solely an elevated IOP, leads to structural and functional vision loss, is still controversial. If the theory is true, a drug that simultaneously lowers both the IOP and ICP may be ineffective. The aim of this study was to determine how acetazolamide (AAZ; a drug prescribed in glaucoma that aims to lower the IOP) affects both IOP and ICP in glaucoma patients and to compare the magnitude and time course of the induced pressure changes with those of healthy subjects not taking AAZ. IOP and noninvasive ICP (measured through emissions from the ear) were measured in 20 glaucoma patients taking 125 mg of AAZ twice daily. Measurements were taken for 30 minutes before taking the drug and for 2 hours post-ingestion. Comparisons were made with 13 age-similar controls. After 12 hours with no anti-glaucoma medication, AAZ did not further reduce IOP in glaucoma patients compared to controls (P = 0.58) but did reduce ICP compared to controls (P = 0.035), by approximately 4 mmHg. Our findings suggest that there are periods during the day when the pressure difference across the lamina cribrosa is larger in case of AAZ use. Future studies should focus on improving the noninvasive ICP testing, different doses and dosing schedules of AAZ, and the time course of IOP in glaucoma patients not taking AAZ.
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Affiliation(s)
- Allison R. Loiselle
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Emile de Kleine
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Pim van Dijk
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nomdo M. Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail:
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36
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Pircher A, Killer HE. Comment on: The role of intracranial pressure in glaucoma. Eye (Lond) 2020; 35:1793. [PMID: 32461563 DOI: 10.1038/s41433-020-0975-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 05/13/2020] [Accepted: 05/13/2020] [Indexed: 11/09/2022] Open
Affiliation(s)
- Achmed Pircher
- Department of Neuroscience/Ophthalmology, Uppsala University, Uppsala, Sweden.,Department of Ophthalmology, Kantonsspital Aarau, Aarau, Switzerland
| | - Hanspeter E Killer
- Department of Ophthalmology, Kantonsspital Aarau, Aarau, Switzerland. .,Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland.
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37
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Baneke AJ, Aubry J, Viswanathan AC, Plant GT. Response to "Comment on: The role of intracranial pressure in glaucoma and therapeutic implications". Eye (Lond) 2020; 35:1782. [PMID: 32444862 DOI: 10.1038/s41433-020-0977-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/23/2020] [Accepted: 05/13/2020] [Indexed: 11/09/2022] Open
Affiliation(s)
- Alex J Baneke
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.
| | - James Aubry
- General Electric Oil and Gas, Florence, Italy
| | - Ananth C Viswanathan
- NIHR Biomedical Research Centre for Ophthalmology at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Gordon T Plant
- Institute of Neurology, University College London, London, UK
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38
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Najmanová E, Pluháček F, Haklová M. Intraocular pressure response affected by changing of sitting and supine positions. Acta Ophthalmol 2020; 98:e368-e372. [PMID: 31602816 PMCID: PMC7216979 DOI: 10.1111/aos.14267] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/15/2019] [Indexed: 01/14/2023]
Abstract
PURPOSE To assess the intraocular pressure (IOP) time response to change in body position from sitting to supine and from supine to sitting immediately and during rest in each position. METHODS Forty-four visually healthy volunteers were recruited for the study. The experiment consisted of the initial sitting position (baseline state), the subsequent lying period and the final sitting period. Both periods were 30 min long. The IOP was measured in the baseline state, immediately after each position change and then in minutes 5, 15, 25 and 30 during each period. The Icare Pro® rebound tonometer was used. RESULTS The mean IOP increased after each position change (2.6 ± 2.4 mmHg after lying down and 2.1 ± 3.1 mmHg after sitting up) and then gradually decreased with time. The mean IOP was 1.41 ± 2.4 mmHg higher in the lying period than in the sitting period; the mean difference was smaller for the lower baseline (0.9 ± 2.2 mmHg) than the higher baseline (1.9 ± 2.5 mmHg). The mean IOP in the final sitting was significantly lower (2.5 ± 1.9 mmHg) than in the initial sitting position. The effect of sex was insignificant. CONCLUSIONS There was an immediate increase in IOP as a response to both changes in the body position and the subsequent gradual decrease with time. The IOP difference between lying and sitting position was depended on baseline.
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Affiliation(s)
- Eliška Najmanová
- Faculty of ScienceDepartment of OpticsPalacký University OlomoucOlomoucCzech Republic
| | - František Pluháček
- Faculty of ScienceDepartment of OpticsPalacký University OlomoucOlomoucCzech Republic
| | - Markéta Haklová
- Faculty of ScienceDepartment of OpticsPalacký University OlomoucOlomoucCzech Republic
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39
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Händel A, Stern C, Jordan J, Dietlein T, Enders P, Cursiefen C. [Eye changes in space : New insights into clinical aspects, pathogenesis and prevention]. Ophthalmologe 2020; 117:721-729. [PMID: 32347333 DOI: 10.1007/s00347-020-01103-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND More than ever research into changes in the eye caused by long-term space flight is becoming the focus of the international and national space agencies National Aeronautics and Space Administration (NASA), European Space Agency (ESA) and German Aerospace Center (DLR). In addition to space radiation-induced cataract formation considerable eye changes, summarized under space flight-associated neuro-ocular syndrome (SANS), can occur. OBJECTIVE This article gives an overview of the current state of research and future directions in the field of research concerned with ocular alterations in SANS and presents the relevance for terrestrial ophthalmological research. MATERIAL AND METHODS An analysis of existing publications on SANS in PubMed and reports on the risk of SANS published by the NASA of the USA was carried out. RESULTS The reasons for the development of the eye changes in space have not been clarified. Factors such as the increase in intracranial pressure, fluid shifts, hypercapnia and genetic factors are the subject of intensive research efforts. A terrestrial model for the induction of papilledema could be established (bed rest studies with -6° head-down tilt as a space analogue). Countermeasures for the development of eye changes, such as intermittent artificial gravity, are the subject of current research studies. CONCLUSION Research into SANS as part of bed rest studies will provide further important insights in the future for space research and also for terrestrial research. Clinical research projects can be derived from space research.
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Affiliation(s)
- A Händel
- Zentrum für Augenheilkunde, Universitätsklinik Köln, Kerpener Str. 62, 50937, Köln, Deutschland.
| | - C Stern
- Institut für Luft- und Raumfahrtmedizin, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Köln, Deutschland
| | - J Jordan
- Institut für Luft- und Raumfahrtmedizin, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Köln, Deutschland.,Lehrstuhl für Luft- und Raumfahrtmedizin, Universitätsklinik Köln, Köln, Deutschland
| | - T Dietlein
- Zentrum für Augenheilkunde, Universitätsklinik Köln, Kerpener Str. 62, 50937, Köln, Deutschland
| | - P Enders
- Zentrum für Augenheilkunde, Universitätsklinik Köln, Kerpener Str. 62, 50937, Köln, Deutschland
| | - C Cursiefen
- Zentrum für Augenheilkunde, Universitätsklinik Köln, Kerpener Str. 62, 50937, Köln, Deutschland
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40
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Abstract
Many experiments have documented the response of intraocular pressure (IOP) to postural change. External forces caused by gravitational orientation change produce a dynamic response that is encountered every day during normal activities. Tilting the body at a small downward angle is also relevant to studying the effects of hypogravity (spaceflight), including ocular changes. We examined data from 36 independent datasets from 30 articles on IOP response to postural change, representing a total population of 821 subjects (≥1173 eyes) with widely varying initial and final postures. We confirmed that IOP was well predicted by a simple quantity, namely the hydrostatic pressure at the level of the eye, although the dependence was complex (nonlinear). Our results show that posturally induced IOP change can be explained by hydrostatic forcing plus an autoregulatory contribution that is dependent on hydrostatic effects. This study represents data from thousands of IOP measurements and provides insight for future studies that consider postural change in relation to ocular physiology, intraocular pressure, ocular blood flow and aqueous humor dynamics.
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41
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Demer JL, Clark RA, Suh SY, Giaconi JA, Nouri-Mahdavi K, Law SK, Bonelli L, Coleman AL, Caprioli J. Optic Nerve Traction During Adduction in Open Angle Glaucoma with Normal versus Elevated Intraocular Pressure. Curr Eye Res 2020; 45:199-210. [PMID: 31453714 PMCID: PMC7398593 DOI: 10.1080/02713683.2019.1660371] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/05/2019] [Accepted: 08/21/2019] [Indexed: 12/15/2022]
Abstract
Purpose/Aim: We used magnetic resonance imaging (MRI) to investigate effects of intraocular pressure (IOP), race, and other factors on optic nerve (ON) traction in adduction, a phenomenon proposed as neuropathic in open angle glaucoma (OAG).Materials and Methods: Thirty-five patients with OAG (26 with maximal untreated IOP ≤21 mmHg, 9 with IOP >21mmHg) and 48 controls underwent axial and quasi-coronal MRI in central gaze and large (27-33°) abduction and adduction. Some underwent MRI at smaller ductions (21-28°). Effects of presence vs. absence of OAG; within OAG whether maximum IOP level was ≤21 mmHg vs. >21 mmHg; adduction angle; race; age; and gender on ON path length and globe translation were analyzed using generalized estimating equations to account for possible intereye correlations of individual subjects.Results: Average visual field mean deviation (±standard error of mean, SEM) was -8.2 ± 1.2 dB in OAG with normal IOP, and -6.1 ± 1.4 in high IOP. In central gaze, ON path in OAG was significantly more redundant than in controls but in both groups the ON became significantly and almost equally straighter in small (~21°) or large (~27°) adduction than in central gaze. With progressive adduction only, globes retracted in OAG (P < 0.005) but not in controls; this was only weakly related to globe size and not to IOP elevation. Globe retraction in adduction was significant only in OAG, and in that group was significantly greater in Asian than white patients (P < 0.02).Conclusions: Although ON tethering in adduction is normal, progressive adduction is associated with abnormal globe retraction in OAG regardless of IOP level. This phenomenon is more prominent in Asians who have OAG. Traction in adduction may cause repetitive strain injury to the ON and peripapillary sclera, thus contributing to the optic neuropathy of glaucoma independent of IOP.
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Affiliation(s)
- Joseph L. Demer
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
- Biomedical Engineering Interdepartmental Program; University of California, Los Angeles
- Neuroscience Interdepartmental Program; University of California, Los Angeles
- Department of Neurology, University of California, Los Angeles
| | - Robert A. Clark
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
| | - Soh Youn Suh
- Department of Ophthalmology, University of California, Los Angeles
| | - JoAnn A. Giaconi
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
| | - Kouros Nouri-Mahdavi
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
| | - Simon K. Law
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
| | - Laura Bonelli
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
| | - Anne L. Coleman
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
| | - Joseph Caprioli
- Department of Ophthalmology, University of California, Los Angeles
- Stein Eye Institute; University of California, Los Angeles
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42
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Liu KC, Fleischman D, Lee AG, Killer HE, Chen JJ, Bhatti MT. Current concepts of cerebrospinal fluid dynamics and the translaminar cribrosa pressure gradient: a paradigm of optic disk disease. Surv Ophthalmol 2020; 65:48-66. [DOI: 10.1016/j.survophthal.2019.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/07/2019] [Accepted: 08/16/2019] [Indexed: 12/11/2022]
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43
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Baneke AJ, Aubry J, Viswanathan AC, Plant GT. The role of intracranial pressure in glaucoma and therapeutic implications. Eye (Lond) 2020; 34:178-191. [PMID: 31776450 PMCID: PMC7002772 DOI: 10.1038/s41433-019-0681-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 11/09/2022] Open
Abstract
Despite glaucoma being the second leading cause of blindness globally, its pathogenesis remains incompletely understood. Although intraocular pressure (IOP) contributes to glaucoma, and reducing IOP slows progress of the disease, some patients progress despite normal IOP (NTG). Glaucomatous damage causes characteristic cupping of the optic nerve where it passes through the lamina cribrosa. There is evidence that cerebrospinal fluid (CSF) within the optic nerve sheath has a different composition from CSF surrounding the brain. Furthermore, fluctuations in CSF flow into the optic nerve sheath may be reduced by trabeculae within the sheath, and on standing intracranial pressure (ICP) within the sheath is stabilised at around 3 mmHg due to orbital pressure. Blood pressure has been linked both to glaucoma and ICP. These facts have led some to conclude that ICP does not play a role in glaucoma. However, according to stress formulae and Laplace's Law, stress within the lamina cribrosa is dependent on the forces on either side of it, (IOP and ICP), and its thickness. On lying flat at night, ICP between the brain and optic nerve sheath should equalise. Most evidence suggests ICP is lower in glaucoma than in control groups, and that the lamina cribrosa is thinner and more posteriorly displaced in glaucoma. Subjects who have had ICP reduced have developed signs of glaucoma. This review finds most evidence supports a role for low ICP in the pathogenesis of glaucoma. Caffeine, theophylline and vitamin A may increase ICP, and could be new candidates for an oral treatment.
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Affiliation(s)
- Alex J Baneke
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.
| | - James Aubry
- General Electric Oil and Gas, Florence, Italy
| | - Ananth C Viswanathan
- NIHR Biomedical Research Centre for Ophthalmology at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Gordon T Plant
- Institute of Neurology, University College London, London, UK
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44
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The Influence of Translaminar Pressure Gradient and Intracranial Pressure in Glaucoma: A Review. J Glaucoma 2019; 29:141-146. [DOI: 10.1097/ijg.0000000000001421] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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45
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Mirra S, Marfany G, Garcia-Fernàndez J. Under pressure: Cerebrospinal fluid contribution to the physiological homeostasis of the eye. Semin Cell Dev Biol 2019; 102:40-47. [PMID: 31761444 DOI: 10.1016/j.semcdb.2019.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 11/05/2019] [Indexed: 01/27/2023]
Abstract
The cerebrospinal fluid (CSF) is a waterly, colorless fluid contained within the brain ventricles and the cranial and spinal subarachnoid spaces. CSF physiological functions range from hydromechanical protection of the central nervous system (CNS) to CNS modulation of developmental processes and regulation of interstitial fluid homeostasis. Optic nerve (ON) is surrounded by CSF circulating in the subarachnoid spaces and is exposed to both CSF (CSFP) and intra ocular (IOP) pressures, which converge at the lamina cribrosa (LC) as two opposite forces. The trans-lamina cribrosa pressure gradient (TLPG) is defined as IOP - CSFP and its alterations (due either to an elevation in IOP or a reduction in ICP) could result in structural damaging of the ON, including glaucomatous changes. The purpose of this review is to update the readers on the CSF contribution in controlling the functions/dysfunctions of ON by regulating homeostasis at LC. We also highlight emerging parallelisms regarding the expression of cilia-related genes in the regulation of common functions of body fluids in both brain and eye structures.
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Affiliation(s)
- Serena Mirra
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, and Institut de Biomedicina (IBUB), University of Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.
| | - Gemma Marfany
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, and Institut de Biomedicina (IBUB), University of Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.
| | - Jordi Garcia-Fernàndez
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, and Institut de Biomedicina (IBUB), University of Barcelona, Barcelona, Spain.
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46
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Price DA, Grzybowski A, Eikenberry J, Januleviciene I, Verticchio Vercellin AC, Mathew S, Siesky B, Harris A. Review of non-invasive intracranial pressure measurement techniques for ophthalmology applications. Br J Ophthalmol 2019; 104:887-892. [PMID: 31704702 DOI: 10.1136/bjophthalmol-2019-314704] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/23/2019] [Accepted: 10/30/2019] [Indexed: 11/04/2022]
Abstract
Assessment and monitoring of intracranial pressure (ICP) are important in the management of traumatic brain injury and other cerebral pathologies. In the eye, ICP elevation and depression both correlate with optic neuropathies, the former because of papilledema and the latter related to glaucoma. While the relationship between ICP elevation and papilledema is well established, the relationship between low ICP and glaucoma is still poorly understood. So far, ICP monitoring is performed invasively, but this entails risks including infection, spurring the study of non-invasive alternatives. We review 11 methods of non-invasive estimation of ICP including correlation to optic nerve sheath diameter, intraocular pressure, ophthalmodynamometry and two-depth transcranial Doppler of the ophthalmic artery. While none of these methods can fully replace invasive techniques, certain measures show great potential for specific applications. Although only used in small studies to date, a MRI based method known as MR-ICP, appears to be the best non-invasive technique for estimating ICP, with two-depth transcranial ultrasound and ophthalmodynamometry showing potential as well.
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Affiliation(s)
- David Andrew Price
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Andrzej Grzybowski
- Department of Ophthalmology, Poznan City Hospital, Poznan, Poland.,Medcial Faculty, University of Warmia and Mazury, Olsztyn, Poland
| | - Jennifer Eikenberry
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | | | | | - Sunu Mathew
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Brent Siesky
- Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, New York City, New York, USA
| | - Alon Harris
- Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, New York City, New York, USA
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47
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Westlund A, Holmlund P, Johansson E, Malm J, Eklund A. Semi-automatic method for segmentation of the internal jugular vein in ultrasound movies evaluated at different body postures. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab285e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
Objective: The collapse of the internal jugular vein (IJV) regulates intracranial pressure (ICP) in upright body positions. The cross-section area (CSA) is therefore of interest when studying the effects of postural changes in various neurological diseases. We have developed a semi-automatic segmentation method, which tracks the CSA of the IJV in ultrasound movies, and evaluated its performance in three body positions (supine, 16°, 71°). Approach: The proposed method utilized post-processing image filtering combined with a modified snake active contour algorithm. The ultrasound movies were retrospectively analysed (n = 231, 3s, 28 fps) based on previously collected data from 17 healthy volunteers. The computed CSAs (CA) from the segmentation method were compared to manually segmented CSAs (MA) in two frames per movie. Tracking performance were evaluated by visual inspection. Main results: In the supine position, 100% of the ultrasound movies were tracked successfully, and the mean of CA-MA was −4.4 ± 6.9 mm2 (MA, 88.4 ± 50.5 mm2). The most challenging movies occurred in upright body posture where tracking success rate was 90% and mean of CA-MA was −1.4 ± 2.2 mm2 (MA, 12.0 ± 11.1 mm2). The semi-automatic segmentations took 55 s to perform on average (per movie) compared to manual segmentations which took 50 min. Significance: Segmentations made by the proposed method were comparable to manual segmentations in all tilt-angles, however much faster. Efficient and accurate tracking of the CSA of the IJV, with respect to postural changes, could help furthering our understanding of how IJV-biomechanics relates to regulation of intracranial pressure in different neurological diseases and physiological states.
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48
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Brain Physiological Response and Adaptation During Spaceflight. Neurosurgery 2019; 85:E815-E821. [DOI: 10.1093/neuros/nyz203] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 02/11/2019] [Indexed: 01/17/2023] Open
Abstract
Abstract
More than half of astronauts returning from long-duration missions on the International Space Station present with neuro-ocular structural and/or functional changes, including optic disc edema, optic nerve sheath distension, globe flattening, choroidal folds, or hyperopic shifts. This spaceflight-associated neuro-ocular syndrome (SANS) represents a major risk to future exploration class human spaceflight missions, including Mars missions. Although the exact pathophysiology of SANS is unknown, evidence thus far suggests that an increase in intracranial pressure (ICP) relative to the upright position on Earth, which is due to the loss of hydrostatic pressure gradients in space, may play a leading role. This review focuses on brain physiology in the spaceflight environment, specifically on how spaceflight may affect ICP and related indicators of cranial compliance, potential factors related to the development of SANS, and findings from spaceflight as well as ground-based spaceflight analog research studies.
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49
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Kim YW, Lee DH, Lim HB, Oh BL, Kim YK, Girard MJA, Mari JM, Park KH, Jeoung JW. Age-Dependent Variation of Lamina Cribrosa Displacement During the Standardized Valsalva Maneuver. Sci Rep 2019; 9:6645. [PMID: 31040379 PMCID: PMC6491605 DOI: 10.1038/s41598-019-43206-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 04/17/2019] [Indexed: 01/17/2023] Open
Abstract
Based on biomechanical theory, lamina cribrosa (LC) displacement, the key component of progressive glaucomatous change, is presumed to be dependent on intraocular pressure (IOP) as well as tissue stiffness of LC. In the performance of the Valsalva maneuver, both IOP and cerebrospinal fluid pressure can increase. The present study investigated the age-dependent variation of LC displacement during the standardized Valsalva maneuver in healthy subjects. Sixty-three (63) eyes (age range: 20-76 years) were prospectively underwent IOP measurement and Cirrus HD-OCT optic disc scans before and during the standardized Valsalva maneuver. During the standardized Valsalva maneuver, the IOP significantly increased from 13.2 ± 2.9 mmHg to 18.6 ± 5.2 mmHg (P < 0.001). The maximal LC depth significantly decreased in the younger age groups (age: 20 s to 40 s) but not in the older age groups (age: over 50). The BMO distance did not change significantly. Younger age (P = 0.009), a smaller increase of IOP during the Valsalva maneuver (P = 0.002), and greater baseline maximal LC depth (P = 0.013) were associated with more anterior displacement of the LC during the standardized Valsalva maneuver. Taken together, age as well as translaminar pressure dynamics seems to play a crucial role in LC biomechanics.
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Affiliation(s)
- Yong Woo Kim
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.,Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, Korea
| | - Dong Hyun Lee
- Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, Korea
| | - Hyung Bin Lim
- Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, Korea
| | - Baek-Lok Oh
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.,Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, Korea
| | - Young Kook Kim
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Michael J A Girard
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore
| | | | - Ki Ho Park
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Jin Wook Jeoung
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
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Smith DW, Lee CJ, Morgan W, Gardiner BS. Estimating three-dimensional outflow and pressure gradients within the human eye. PLoS One 2019; 14:e0214961. [PMID: 30964894 PMCID: PMC6456205 DOI: 10.1371/journal.pone.0214961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/23/2019] [Indexed: 12/22/2022] Open
Abstract
In this paper we set the previously reported pressure-dependent, ordinary differential equation outflow model by Smith and Gardiner for the human eye, into a new three-dimensional (3D) porous media outflow model of the eye, and calibrate model parameters using data reported in the literature. Assuming normal outflow through anterior pathways, we test the ability of 3D flow model to predict the pressure elevation with a silicone oil tamponade. Then assuming outflow across the retinal pigment epithelium is normal, we test the ability of the 3D model to predict the pressure elevation in Schwartz-Matsuo syndrome. For the first time we find the flow model can successfully model both conditions, which helps to build confidence in the validity and accuracy of the 3D pressure-dependent outflow model proposed here. We employ this flow model to estimate the translaminar pressure gradient within the optic nerve head of a normal eye in both the upright and supine postures, and during the day and at night. Based on a ratio of estimated and measured pressure gradients, we define a factor of safety against acute interruption of axonal transport at the laminar cribrosa. Using a completely independent method, based on the behaviour of dynein molecular motors, we compute the factor of safety against stalling the dynein molecule motors, and so compromising retrograde axonal transport. We show these two independent methods for estimating factors of safety agree reasonably well and appear to be consistent. Taken together, the new 3D pressure-dependent outflow model proves itself to capable of providing a useful modeling platform for analyzing eye behaviour in a variety of physiological and clinically useful contexts, including IOP elevation in Schwartz-Matsuo syndrome and with silicone oil tamponade, and potentially for risk assessment for optic glaucomatous neuropathy.
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Affiliation(s)
- David W. Smith
- Faculty of Engineering and Mathematical Sciences, The University of Western Australia, Perth, Australia
- * E-mail:
| | - Chang-Joon Lee
- Faculty of Engineering and Mathematical Sciences, The University of Western Australia, Perth, Australia
- College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Western Australia, Australia
| | - William Morgan
- Lions Eye Institute, The University of Western Australia, Perth, Australia
| | - Bruce S. Gardiner
- College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Western Australia, Australia
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