1
|
Liu T, Hung PT, Wang X, Girard MJA. Effect of Eye Globe and Optic Nerve Morphologies on Gaze-Induced Optic Nerve Head Deformations. Invest Ophthalmol Vis Sci 2024; 65:48. [PMID: 39083312 PMCID: PMC11290562 DOI: 10.1167/iovs.65.8.48] [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: 12/20/2023] [Accepted: 06/25/2024] [Indexed: 08/02/2024] Open
Abstract
Purpose The purpose of this study was to investigate the effect of globe and optic nerve (ON) morphologies and tissue stiffnesses on gaze-induced optic nerve head deformations using parametric finite element modeling and a design of experiment (DOE) approach. Methods A custom software was developed to generate finite element models of the eye using 10 morphological parameters: dural radius, scleral, choroidal, retinal, pial and peripapillary border tissue thicknesses, prelaminar tissue depth, lamina cribrosa (LC) depth, ON radius, and ON tortuosity. A central composite face-centered design (1045 models) was used to predict the effects of each morphological factor and their interactions on LC strains induced by 13 degrees of adduction. Subsequently, a further DOE analysis (1045 models) was conducted to study the effects and potential interactions between the top five morphological parameters identified from the initial DOE study and five critical tissue stiffnesses. Results In the DOE analysis of 10 morphological parameters, the 5 most significant factors were ON tortuosity, dural radius, ON radius, scleral thickness, and LC depth. Further DOE analysis incorporating biomechanical parameters highlighted the importance of dural and LC stiffness. A larger dural radius and stiffer dura increased LC strains but the other main factors had the opposite effects. Notably, the significant interactions were found between dural radius with dural stiffness, ON radius, and ON tortuosity. Conclusions This study highlights the significant impact of morphological factors on LC deformations during eye movements, with key morphological effects being more pronounced than tissue stiffnesses.
Collapse
Affiliation(s)
- Tingting Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Pham Tan Hung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Xiaofei Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- School of Ophthalmology and Optometry and School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China
| | - Michaël J. A. Girard
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, Singapore
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, Georgia, United States
- Emory Empathetic AI for Health Institute, Emory University, Atlanta, Georgia, United States
| |
Collapse
|
2
|
Wang TW, Huang MK, Hsu CC, Jo SY, Lin YK, How CK, Tseng SF, Chung K, Chien DK, Chang WH, Chiu YH. High myopia at high altitudes. Front Physiol 2024; 15:1350051. [PMID: 38523807 PMCID: PMC10957768 DOI: 10.3389/fphys.2024.1350051] [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: 12/07/2023] [Accepted: 02/08/2024] [Indexed: 03/26/2024] Open
Abstract
Background: Optic nerve sheath diameter (ONSD) increases significantly at high altitudes, and is associated with the presence and severity of acute mountain sickness (AMS). Exposure to hypobaria, hypoxia, and coldness when hiking also impacts intraocular pressure (IOP). To date, little is known about ocular physiological responses in trekkers with myopia at high altitudes. This study aimed to determine changes in the ONSD and IOP between participants with and without high myopia (HM) during hiking and to test whether these changes could predict symptoms of AMS. Methods: Nine participants with HM and 18 without HM participated in a 3-day trek of Xue Mountain. The ONSD, IOP, and questionnaires were examined before and during the trek of Xue Mountain. Results: The ONSD values increased significantly in both HM (p = 0.005) and non-HM trekkers (p = 0.018) at an altitude of 1,700 m. In the HM group, IOP levels were greater than those in the non-HM group (p = 0.034) on the first day of trekking (altitude: 3,150 m). No statistically significant difference was observed between the two groups for the values of ONSD. Fractional changes in ONSD at an altitude of 1,700 m were related to the development of AMS (r pb = 0.448, p = 0.019) and the presence of headache symptoms (r pb = 0.542, p = 0.004). The area under the ROC curve for the diagnostic performance of ONSD fractional changes at an altitude of 1,700 m was 0.859 for predicting the development of AMS and 0.803 for predicting the presence of headache symptoms. Conclusion: Analysis of changes in ONSD at moderate altitude could predict AMS symptoms before an ascent to high altitude. Myopia may impact physiological accommodation at high altitudes, and HM trekkers potentially demonstrate suboptimal regulation of aqueous humor in such environments.
Collapse
Affiliation(s)
- Ta-Wei Wang
- Department of Emergency Medicine, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan
| | - Ming-Kun Huang
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
- Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan
| | - Chih-Chun Hsu
- Department of Emergency, Hsinchu MacKay Memorial Hospital, Hsinchu, Taiwan
| | - Szu-Yang Jo
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
| | - Yen-Kuang Lin
- Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, Taoyuan, Taiwan
| | - Chorng-Kuang How
- Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Emergency Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Shih-Fen Tseng
- Department of Emergency Medicine, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan
| | - Kong Chung
- Department of Emergency Medicine, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan
| | - Ding-Kuo Chien
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Wen-Han Chang
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Yu-Hui Chiu
- Department of Emergency Medicine, MacKay Memorial Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
- Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Muñoz Sarmiento DM, Rodríguez Montaño ÓL, Alarcón Castiblancoa JD, Cortés Rodríguez CJ. The impact of horizontal eye movements versus intraocular pressure on optic nerve head biomechanics: A tridimensional finite element analysis study. Heliyon 2023; 9:e13634. [PMID: 36865452 PMCID: PMC9970910 DOI: 10.1016/j.heliyon.2023.e13634] [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: 08/25/2022] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/13/2023] Open
Abstract
It has been proposed that eye movements could be related to glaucoma development. This research aimed to compare the impact of intraocular pressure (IOP) versus horizontal duction on optic nerve head (ONH) strains. Thus, a tridimensional finite element model of the eye including the three tunics of the eye, all of the meninges, and the subarachnoid space (SAS) was developed using a series of medical tests and anatomical data. The ONH was divided into 22 subregions, and the model was subjected to 21 different eye pressures, as well as 24 different degrees of adduction and abduction ranging from 0.5° to 12°. Mean deformations were documented along anatomical axes and in principal directions. Additionally, the impact of tissue stiffness was assessed. The results show no statistically significant differences between the lamina cribrosa (LC) strains due to eye rotation and IOP variation. However, when assessing LC regions some experienced a reduction in principal strains following a 12° duction, while after the IOP reached 12 mmHg, all LC subzones showed an increase in strains. From an anatomical perspective, the effect on the ONH following 12° duction was opposite to that observed after a rise in IOP. Moreover, high strain dispersion inside the ONH subregions was obtained with lateral eye movements, which was not observed with increased IOP and variation. Finally, SAS and orbital fat stiffness strongly influenced ONH strains during eye movements, while SAS stiffness was also influential under ocular hypertension. Even if horizontal eye movements cause large ONH deformations, their biomechanical effect would be markedly distinct from that induced by IOP. It could be predicted that, at least in physiological conditions, their potential to cause axonal injury would not be so relevant. Thus, a causative role in glaucoma does not appear likely. By contrast, an important role of SAS would be expectable.
Collapse
Affiliation(s)
- Diana Marcela Muñoz Sarmiento
- Grupo de Investigación en Biomecánica, Universidad Nacional de Colombia, Colombia,Sociedad de Oftalmología Eduardo Arenas Archila, Colombia,Laboratorio de Anatomía y Fisiología, Grupo de Ciencias Básicas y Laboratorios, Universidad Manuela Beltrán, Colombia,Corresponding author. Grupo de Investigación en Biomecánica, Universidad Nacional de Colombia, Colombia.
| | | | | | | |
Collapse
|
5
|
Gupta V, Singh M, Gupta R, Kumar B, Agarwal D. Development of an Automated Algorithm to Quantify Optic Nerve Diameter Using Ultrasound Measures: Implications for Optic Neuropathies. LECTURE NOTES IN NETWORKS AND SYSTEMS 2023:283-295. [DOI: 10.1007/978-981-19-7867-8_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2025]
|
6
|
Hwang HB, Yeon JS, Moon GS, Jung HN, Kim JY, Jeon SH, Yoon JM, Kim HW, Kim YC. 3D Reconstruction of a Unitary Posterior Eye by Converging Optically Corrected Optical Coherence and Magnetic Resonance Tomography Images via 3D CAD. Transl Vis Sci Technol 2022; 11:24. [PMID: 35895054 PMCID: PMC9344223 DOI: 10.1167/tvst.11.7.24] [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] [Indexed: 12/02/2022] Open
Abstract
Purpose In acquiring images of the posterior eye, magnetic resonance imaging (MRI) provides low spatial resolution of the overall shape of the eye while optical coherence tomography (OCT) offers high spatial resolution of the limited range. Through the merger of the two devices, we attempted to acquire detailed anatomy of the posterior eye. Methods Optical and display distortions in OCT images were corrected using the Listing reduced eye model. The 3.0T orbital MRI images were placed on the three-dimensional coordinate system of the computer-aided design (CAD) program. Employing anterior scleral canal opening, visual axis, and scleral curvature as references, original and corrected OCT images were ported into the CAD application. The radii of curvature of the choroid–scleral interfaces (Rc values) of all original and corrected OCT images were compared to the MRI images. Results Sixty-five eyes of 33 participants (45.58 ± 19.82 years) with a mean Rc of 12.94 ± 1.24 mm on axial MRI and 13.66 ± 2.81 mm on sagittal MRI were included. The uncorrected horizontal OCT (30.51 ± 9.34 mm) and the uncorrected vertical OCT (34.35 ± 18.09 mm) lengths differed significantly from the MRI Rc values (both P < 0.001). However, the mean Rc values of the corrected horizontal (12.50 ± 1.21 mm) and vertical (13.05 ± 1.98 mm) images did not differ significantly from the Rc values of the corresponding MRI planes (P = 0.065 and P = 0.198, respectively). Conclusions Features identifiable only on OCT and features only on MRI were successfully integrated into a unitary posterior eye. Translational Relevance Our CAD-based converging method may establish the collective anatomy of the posterior eye and the neural canal, beyond the range of the OCT.
Collapse
Affiliation(s)
- Hyung Bin Hwang
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.,Department of Ophthalmology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | | | | | | | | | - Seung Hee Jeon
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.,Department of Ophthalmology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joon Myoung Yoon
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.,Department of Ophthalmology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hyo Won Kim
- Gangnam St. Mary's One Eye Clinic, Seoul, Republic of Korea
| | - Yong Chan Kim
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.,Department of Ophthalmology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| |
Collapse
|
7
|
Wiseman SJ, Tatham AJ, Meijboom R, Terrera GM, Hamid C, Doubal FN, Wardlaw JM, Ritchie C, Dhillon B, MacGillivray T. Measuring axial length of the eye from magnetic resonance brain imaging. BMC Ophthalmol 2022; 22:54. [PMID: 35123441 PMCID: PMC8817515 DOI: 10.1186/s12886-022-02289-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 01/27/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Metrics derived from the human eye are increasingly used as biomarkers and endpoints in studies of cardiovascular, cerebrovascular and neurological disease. In this context, it is important to account for potential confounding that can arise from differences in ocular dimensions between individuals, for example, differences in globe size. METHODS We measured axial length, a geometric parameter describing eye size from T2-weighted brain MRI scans using three different image analysis software packages (Mango, ITK and Carestream) and compared results to biometry measurements from a specialized ophthalmic instrument (IOLMaster 500) as the reference standard. RESULTS Ninety-three healthy research participants of mean age 51.0 ± SD 5.4 years were analyzed. The level of agreement between the MRI-derived measurements and the reference standard was described by mean differences as follows, Mango - 0.8 mm; ITK - 0.5 mm; and Carestream - 0.1 mm (upper/lower 95% limits of agreement across the three tools ranged from 0.9 mm to - 2.6 mm). Inter-rater reproducibility was between - 0.03 mm and 0.45 mm (ICC 0.65 to 0.93). Intra-rater repeatability was between 0.0 mm and - 0.2 mm (ICC 0.90 to 0.95). CONCLUSIONS We demonstrate that axial measurements of the eye derived from brain MRI are within 3.5% of the reference standard globe length of 24.1 mm. However, the limits of agreement could be considered clinically significant. Axial length of the eye obtained from MRI is not a replacement for the precision of biometry, but in the absence of biometry it could provide sufficient accuracy to act as a proxy. We recommend measuring eye axial length from MRI in studies that do not have biometry but use retinal imaging to study neurodegenerative changes so as to control for differing eye size across individuals.
Collapse
Affiliation(s)
- Stewart J. Wiseman
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging Facilities, University of Edinburgh, Edinburgh, UK
| | - Andrew J. Tatham
- NHS Lothian Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, UK
| | - Rozanna Meijboom
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Graciela Muniz Terrera
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - Charlene Hamid
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- Edinburgh Imaging Facilities, University of Edinburgh, Edinburgh, UK
| | - Fergus N. Doubal
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
| | - Joanna M. Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging Facilities, University of Edinburgh, Edinburgh, UK
| | - Craig Ritchie
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
| | - Baljean Dhillon
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- NHS Lothian Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, UK
| | - Tom MacGillivray
- Centre for Clinical Brain Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB UK
- Edinburgh Imaging Facilities, University of Edinburgh, Edinburgh, UK
| |
Collapse
|