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Campigotto A, Campbell RJ, Lai Y. Correlation between corneal and contact lens deformation with changes in intraocular pressure for wearable monitoring systems. Eye (Lond) 2023; 37:2055-2060. [PMID: 36302975 PMCID: PMC10333185 DOI: 10.1038/s41433-022-02285-y] [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: 02/18/2022] [Revised: 09/11/2022] [Accepted: 10/07/2022] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE The aim of this work is to evaluate the extent to which the eye's curvature deformation, due to changes in the intraocular pressure (IOP), can be directly tracked by an overlying contact lens. METHOD In this experimental study, using 12 cadaveric eyes, the IOP was increased from 10 to 36 mmHg, while video imaging was used to capture the three experimental variations. The deformation of the bare eye was used as a control, while the deformation of an overlying silicone grided contact lens and an overlying microfluidic IOP-sensing contact lens were examined and compared. RESULTS The relation between the slope of the radius of corneal curvature versus the IOP for both the bare eye and the marker contact lens yielded a linear relationship with a R2 value of 0.83. The microfluidic contact lens resulted in an average performance of 0.40 mm indicator movement/mmHg (SD 0.006). Comparing the slope of the marker contact lens deformation, to the performance of the microfluidic contact lens resulted in a R2 value of 0.78. The strain map of the overlaying grided contact lens showed most deformation occurring along the outer edge of the lens with increased deformation as increase IOP occurs; as well as with some negative, compressive movement near the central points. CONCLUSION The deformation from the curvature of the eye is significant enough from 10 to 36 mmHg that a silicone contact lens can capture and mimic those changes. The results show promise for optimization in contact lens-based IOP monitoring.
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Affiliation(s)
- Angelica Campigotto
- Department of Mechanical and Materials Engineering, Queen's University, Kingston, ON, Canada
| | - Robert J Campbell
- Department of Ophthalmology, Queen's University, Kingston, ON, Canada
- Department of Ophthalmology, Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Yongjun Lai
- Department of Mechanical and Materials Engineering, Queen's University, Kingston, ON, Canada.
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Lee YJ, Choe S, Wy S, Jang M, Jeoung JW, Choi HJ, Park KH, Sun S, Kim YK. Demographics Prediction and Heatmap Generation From OCT Images of Anterior Segment of the Eye: A Vision Transformer Model Study. Transl Vis Sci Technol 2022; 11:7. [DOI: 10.1167/tvst.11.11.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Yun Jeong Lee
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sooyeon Choe
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Seoyoung Wy
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Mirinae Jang
- 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
| | - Hyuk Jin Choi
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Seoul National University Hospital Healthcare System Gangnam Center, Seoul National University College of Medicine, Seoul, Korea
| | - Ki Ho Park
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sukkyu Sun
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Young Kook Kim
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
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Predicting demographic characteristics from anterior segment OCT images with deep learning: A study protocol. PLoS One 2022; 17:e0270493. [PMID: 35951641 PMCID: PMC9371292 DOI: 10.1371/journal.pone.0270493] [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: 09/13/2021] [Accepted: 06/11/2022] [Indexed: 11/19/2022] Open
Abstract
Introduction Anterior segment optical coherence tomography (AS-OCT) is a non-contact, rapid, and high-resolution in vivo modality for imaging of the eyeball’s anterior segment structures. Because progressive anterior segment deformation is a hallmark of certain eye diseases such as angle-closure glaucoma, identification of AS-OCT structural changes over time is fundamental to their diagnosis and monitoring. Detection of pathologic damage, however, relies on the ability to differentiate it from normal, age-related structural changes. Methods and analysis This proposed large-scale, retrospective cross-sectional study will determine whether demographic characteristics including age can be predicted from deep learning analysis of AS-OCT images; it will also assess the importance of specific anterior segment areas of the eyeball to the prediction. We plan to extract, from SUPREME®, a clinical data warehouse (CDW) of Seoul National University Hospital (SNUH; Seoul, South Korea), a list of patients (at least 2,000) who underwent AS-OCT imaging between 2008 and 2020. AS-OCT images as well as demographic characteristics including age, gender, height, weight and body mass index (BMI) will be collected from electronic medical records (EMRs). The dataset of horizontal AS-OCT images will be split into training (80%), validation (10%), and test (10%) datasets, and a Vision Transformer (ViT) model will be built to predict demographics. Gradient-weighted Class Activation Mapping (Grad-CAM) will be used to visualize the regions of AS-OCT images that contributed to the model’s decisions. The accuracy, sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (AUC) will be applied to evaluate the model performance. Conclusion This paper presents a study protocol for prediction of demographic characteristics from AS-OCT images of the eyeball using a deep learning model. The results of this study will aid clinicians in understanding and identifying age-related structural changes and other demographics-based structural differences. Trial registration Registration ID with open science framework:10.17605/OSF.IO/FQ46X.
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Rosa N, De Bernardo M, Pepe A, Vitiello L, Marotta G, Imparato R, Capasso L. Corneal thickness evaluation in healthy eyes: Comparison between two different Scheimpflug devices. PLoS One 2020; 15:e0243370. [PMID: 33270786 PMCID: PMC7714349 DOI: 10.1371/journal.pone.0243370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/19/2020] [Indexed: 11/30/2022] Open
Abstract
Purpose To evaluate the correlation between corneal thickness (CT) measurements obtained with two Scheimpflug devices, Pentacam HR and Precisio, and to elaborate, if necessary, a regression formula which could make these results comparable. Design Retrospective, Comparative, Observational study. Setting Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Italy Methods One hundred twenty four healthy eyes of 124 volunteers (65 males; range: 20–32 years; mean age of 24.8 ± 1.7) were included in this study. CT was measured using Pentacam HR and Precisio in three different points: the pupil center (PC), the corneal apex (CA) and the thinnest point (TP). Results CT obtained with both devices at the PC, at the CA and at the TP showed a good correlation (r = 0.97, r = 0.97, r = 0.97, respectively), but Pentacam HR measurements were significantly thicker than those provided by Precisio (p < 0.01). The differences between Pentacam HR and Precisio were 21.9 ± 8.8 μm at the PC, 21.9 ± 8.9 μm at the CA, 19.1 ± 9.0 μm at the TP. The calculated regression formulas were: y = 0.9558x + 2.3196 for the PC, y = 0.9519x + 4.5626 for the CA, y = 0.9364x + 15.436 for the TP, where x is the CT measured with Pentacam HR and y is the Precisio measurement. Conclusions The findings provided by this study highlight that Precisio measures thinner corneas compared to Pentacam HR. The identified regression formulas could be utilized to make interchangeable the results obtained with these two devices.
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Affiliation(s)
- Nicola Rosa
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Baronissi, Salerno, Italy
| | - Maddalena De Bernardo
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Baronissi, Salerno, Italy
- * E-mail:
| | - Angela Pepe
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Baronissi, Salerno, Italy
| | - Livio Vitiello
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Baronissi, Salerno, Italy
| | - Giuseppe Marotta
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Baronissi, Salerno, Italy
| | - Roberto Imparato
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Baronissi, Salerno, Italy
| | - Luigi Capasso
- Corneal Transplant Unit, ASL Napoli 1, Naples, Italy
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Tong J, Phu J, Kalloniatis M, Zangerl B. Modeling Changes in Corneal Parameters With Age: Implications for Corneal Disease Detection. Am J Ophthalmol 2020; 209:117-131. [PMID: 31469999 DOI: 10.1016/j.ajo.2019.08.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 08/19/2019] [Accepted: 08/19/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE To apply computational methods to model normal age-related changes in corneal parameters and to establish their association with demographic factors, thereby providing a framework for improved detection of subclinical corneal ectasia (SCE). DESIGN Cross-sectional study. METHODS One hundred seventeen healthy participants were enrolled from Centre for Eye Health (Sydney, Australia). Corneal thickness (CT), front surface sagittal curvature (FSSC), and back surface sagittal curvature (BSSC) measurements were extracted from 57 corneal locations from 1 eye per participant using the Pentacam HR. Cluster analyses were performed to identify locations demonstrating similar variations with age. Age-related changes were modeled using polynomial regression with sliding window methods, and model accuracy was verified with Bland-Altman comparisons. Pearson correlations were applied to examine the impacts of demographic factors. RESULTS Concentric cluster patterns were observed for CT and FSSC but not for BSSC. Sliding window analyses were best fit with quartic and cubic regression models for CT and FSSC/BSSC, respectively. CT and FSSC sliding window models had narrower 95% limits of agreement compared with decade-based models (0.015 mm vs 0.017 mm and 0.14 mm vs 0.27 mm, respectively), but were wider for BSSC than decade-based models (0.73 mm vs 0.54 mm). Significant correlations were observed between CT and astigmatism (P = .02-.049) and FSSC and BSSC and gender (P = <.001-.049). CONCLUSIONS The developed models robustly described aging variations in CT and FSSC; however, other mechanisms appear to contribute to variations in BSSC. These findings and the identified correlations provide a framework that can be applied to future model development and establishment of normal databases to facilitate SCE detection.
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Affiliation(s)
- Janelle Tong
- Centre for Eye Health and the School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Jack Phu
- Centre for Eye Health and the School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Michael Kalloniatis
- Centre for Eye Health and the School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Barbara Zangerl
- Centre for Eye Health and the School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia.
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Armstrong RA. Should Pearson's correlation coefficient be avoided? Ophthalmic Physiol Opt 2019; 39:316-327. [PMID: 31423624 DOI: 10.1111/opo.12636] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/18/2019] [Indexed: 01/17/2023]
Abstract
PURPOSE To survey the use of Pearson's correlation coefficient (r) and related statistical methods in the ophthalmic literature, to consider the limitations of r, and to suggest suitable alternative methods of analysis. RECENT FINDINGS Searching Ophthalmic and Physiological Optics (OPO), Optometry and Vision Science (OVS), and Clinical and Experimental Optometry (CXO) online archives using correlation and Pearson's r as search terms resulted in 4057 and 281 hits respectively. Coefficient of determination, r square, or r squared received fewer hits (65, 8, and 22 hits respectively). The assumption that r follows a bivariate normal distribution was rarely encountered (3 hits) although several studies applied Spearman's rank correlation (70 hits). The intra-class correlation coefficient (ICC) was widely used (178 hits), but fewer hits were recorded for partial correlation (43 hits) and multiple correlation (13) hits. There was little evidence that the problem of sample size was addressed in correlation studies. SUMMARY Investigators should be alert to whether: (1) the relationship between two variables could be non-linear, (2) the data are bivariate normal, (3) r accounts for a significant proportion of the variance in Y, (4) outliers are present, the data are clustered, or have a restricted range, (5) the sample size is appropriate, and (6) a significant correlation indicates causality. In addition, the number of significant digits used to express r and the problems of multiple testing should be addressed. The problems and limitations of r suggest a more cautious approach regarding its use and the application of alternative methods where appropriate.
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Affiliation(s)
- Richard A Armstrong
- School of Life and Health Sciences: Ophthalmic Research Group, School of Optometry, Aston University, Birmingham, UK
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Barrientez B, Nicholas SE, Whelchel A, Sharif R, Hjortdal J, Karamichos D. Corneal injury: Clinical and molecular aspects. Exp Eye Res 2019; 186:107709. [PMID: 31238077 DOI: 10.1016/j.exer.2019.107709] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/03/2019] [Accepted: 06/21/2019] [Indexed: 12/13/2022]
Abstract
Currently, over 10 million people worldwide are affected by corneal blindness. Corneal trauma and disease can cause irreversible distortions to the normal structure and physiology of the cornea often leading to corneal transplantation. However, donors are in short supply and risk of rejection is an ever-present concern. Although significant progress has been made in recent years, the wound healing cascade remains complex and not fully understood. Tissue engineering and regenerative medicine are currently at the apex of investigation in the pursuit of novel corneal therapeutics. This review uniquely integrates the clinical and cellular aspects of both corneal trauma and disease and provides a comprehensive view of the most recent findings and potential therapeutics aimed at restoring corneal homeostasis.
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Affiliation(s)
- Brayden Barrientez
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Sarah E Nicholas
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Amy Whelchel
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Rabab Sharif
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Jesper Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | - Dimitrios Karamichos
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
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