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Vinuela-Navarro V, Baker FJ, Woodhouse JM, Sheppard AL. Ciliary muscle and anterior segment characteristics in pre-presbyopic adults with Down syndrome. Ophthalmic Physiol Opt 2024; 44:483-490. [PMID: 38372370 DOI: 10.1111/opo.13290] [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: 10/10/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/20/2024]
Abstract
PURPOSE Previous research has shown that accommodation deficits are common in individuals with Down syndrome (DS), but the origin and mechanisms behind these deficits are still unknown. The aim of this study was to investigate the characteristics of different ocular structures involved in accommodation, in particular the ciliary muscle (CM), in a population of individuals with DS to further understand this deficit and its mechanisms. METHODS Thirty-two volunteer participants of pre-presbyopic age with (n = 16) and without DS (n = 16) were recruited. Temporal and nasal images of the CM were acquired using anterior segment optical coherence tomography (AS-OCT) while participants fixated an eccentrically located target. Analysis of CM parameters was undertaken using validated semi-automated software. Axial length, anterior chamber depth, lens thickness and corneal curvature were obtained with the Topcon Aladdin Optical Biometer and Corneal Topographer. Non-cycloplegic refractive error and accommodative ability were obtained with an open-field autorefractor and dynamic retinoscopy, respectively. Independent t-tests were conducted to determine differences in CM and other anterior segment parameters between participants with and without DS. RESULTS No significant differences were found in the CM parameters studied between participants with and without DS (p > 0.05). In contrast, significant differences were found in visual acuity (p < 0.001), accommodative response (p < 0.001) and corneal curvature (K1 p = 0.003 and K2 p < 0.001) between participants with and without DS. CONCLUSIONS Despite having poorer accommodation, pre-presbyopic adults with DS do not have a different CM morphology to that found in typically developing adults. These findings suggest that the accommodative deficit found in this population is not due to a mechanical deficit of the CM.
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Affiliation(s)
- Valldeflors Vinuela-Navarro
- Visió Optometria i Salut-Department d'Òptica i Optometria de Terrassa, Universitat Politècnica de Catalunya, Terrassa, Barcelona, Spain
- Center for Sensors, Instruments and Systems Development, Universitat Politècnica de Catalunya, Terrassa, Barcelona, Spain
| | - Fiona Jane Baker
- Optometry and Vision Sciences Research Group, Aston University, Birmingham, UK
| | | | - Amy L Sheppard
- Optometry and Vision Sciences Research Group, Aston University, Birmingham, UK
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Chen W, Yu X, Ye Y, Gao H, Cao X, Lin G, Zhang R, Li Z, Wang X, Zhou Y, Shen M, Shao Y. CMS-NET: deep learning algorithm to segment and quantify the ciliary muscle in swept-source optical coherence tomography images. Ther Adv Chronic Dis 2023; 14:20406223231159616. [PMID: 36938499 PMCID: PMC10017933 DOI: 10.1177/20406223231159616] [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: 06/20/2022] [Accepted: 02/07/2023] [Indexed: 03/16/2023] Open
Abstract
Background The ciliary muscle plays a role in changing the shape of the crystalline lens to maintain the clear retinal image during near work. Studying the dynamic changes of the ciliary muscle during accommodation is necessary for understanding the mechanism of presbyopia. Optical coherence tomography (OCT) has been frequently used to image the ciliary muscle and its changes during accommodation in vivo. However, the segmentation process is cumbersome and time-consuming due to the large image data sets and the impact of low imaging quality. Objectives This study aimed to establish a fully automatic method for segmenting and quantifying the ciliary muscle on the basis of optical coherence tomography (OCT) images. Design A perspective cross-sectional study. Methods In this study, 3500 signed images were used to develop a deep learning system. A novel deep learning algorithm was created from the widely used U-net and a full-resolution residual network to realize automatic segmentation and quantification of the ciliary muscle. Finally, the algorithm-predicted results and manual annotation were compared. Results For segmentation performed by the system, the total mean pixel value difference (PVD) was 1.12, and the Dice coefficient, intersection over union (IoU), and sensitivity values were 93.8%, 88.7%, and 93.9%, respectively. The performance of the system was comparable with that of experienced specialists. The system could also successfully segment ciliary muscle images and quantify ciliary muscle thickness changes during accommodation. Conclusion We developed an automatic segmentation framework for the ciliary muscle that can be used to analyze the morphological parameters of the ciliary muscle and its dynamic changes during accommodation.
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Affiliation(s)
| | | | | | - Hebei Gao
- Division of Health Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xinyuan Cao
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Guangqing Lin
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Riyan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Zixuan Li
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Xinmin Wang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Yuheng Zhou
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Meixiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou 325027, China
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Straßer T, Wagner S. Performance of the Deep Neural Network Ciloctunet, Integrated with Open-Source Software for Ciliary Muscle Segmentation in Anterior Segment OCT Images, Is on Par with Experienced Examiners. Diagnostics (Basel) 2022; 12:diagnostics12123055. [PMID: 36553062 PMCID: PMC9777151 DOI: 10.3390/diagnostics12123055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 12/12/2022] Open
Abstract
Anterior segment optical coherence tomography (AS-OCT), being non-invasive and well-tolerated, is the method of choice for an in vivo investigation of ciliary muscle morphology and function. The analysis requires the segmentation of the ciliary muscle, which is, when performed manually, both time-consuming and prone to examiner bias. Here, we present a convolutional neural network trained for the automatic segmentation of the ciliary muscle in AS-OCT images. Ciloctunet is based on the Freiburg U-net and was trained and validated using 1244 manually segmented OCT images from two previous studies. An accuracy of 97.5% for the validation dataset was achieved. Ciloctunet's performance was evaluated by replicating the findings of a third study with 180 images as the test data. The replication demonstrated that Ciloctunet performed on par with two experienced examiners. The intersection-over-union index (0.84) of the ciliary muscle thickness profiles between Ciloctunet and an experienced examiner was the same as between the two examiners. The mean absolute error between the ciliary muscle thickness profiles of Ciloctunet and the two examiners (35.16 µm and 45.86 µm) was comparable to the one between the examiners (34.99 µm). A statistically significant effect of the segmentation type on the derived biometric parameters was found for the ciliary muscle area but not for the selective thickness reading ("perpendicular axis"). Both the inter-rater and the intra-rater reliability of Ciloctunet were good to excellent. Ciloctunet avoids time-consuming manual segmentation, thus enabling the analysis of large numbers of images of ample study cohorts while avoiding possible examiner biases. Ciloctunet is available as open-source.
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Affiliation(s)
- Torsten Straßer
- Institute for Ophthalmic Research, University of Tuebingen, 72076 Tuebingen, Germany
- University Eye Hospital Tuebingen, 72076 Tuebingen, Germany
- Correspondence:
| | - Sandra Wagner
- Institute for Ophthalmic Research, University of Tuebingen, 72076 Tuebingen, Germany
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Cabeza-Gil I, Ruggeri M, Chang YC, Calvo B, Manns F. Automated segmentation of the ciliary muscle in OCT images using fully convolutional networks. BIOMEDICAL OPTICS EXPRESS 2022; 13:2810-2823. [PMID: 35774316 PMCID: PMC9203087 DOI: 10.1364/boe.455661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/15/2022] [Accepted: 03/15/2022] [Indexed: 06/15/2023]
Abstract
Quantifying shape changes in the ciliary muscle during accommodation is essential in understanding the potential role of the ciliary muscle in presbyopia. The ciliary muscle can be imaged in-vivo using OCT but quantifying the ciliary muscle shape from these images has been challenging both due to the low contrast of the images at the apex of the ciliary muscle and the tedious work of segmenting the ciliary muscle shape. We present an automatic-segmentation tool for OCT images of the ciliary muscle using fully convolutional networks. A study using a dataset of 1,039 images shows that the trained fully convolutional network can successfully segment ciliary muscle images and quantify ciliary muscle thickness changes during accommodation. The study also shows that EfficientNet outperforms other current backbones of the literature.
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Affiliation(s)
- Iulen Cabeza-Gil
- Aragón Institute of Engineering Research (i3A), University of Zaragoza, Zaragoza, Spain
| | - Marco Ruggeri
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA
| | - Yu-Cherng Chang
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA
| | - Begoña Calvo
- Aragón Institute of Engineering Research (i3A), University of Zaragoza, Zaragoza, Spain
- Bioengineering, Biomaterials and Nanomedicine Networking Biomedical Research Centre (CIBER-BBN), Zaragoza, Spain
| | - Fabrice Manns
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA
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Monterano Mesquita G, Patel D, Chang YC, Cabot F, Ruggeri M, Yoo SH, Ho A, Parel JMA, Manns F. In vivo measurement of the attenuation coefficient of the sclera and ciliary muscle. BIOMEDICAL OPTICS EXPRESS 2021; 12:5089-5106. [PMID: 34513244 PMCID: PMC8407821 DOI: 10.1364/boe.427286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/30/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
We acquired 1325 nm OCT images of the sclera and ciliary muscle of human subjects. The attenuation coefficients of the sclera and ciliary muscle were determined from a curve fit of the average intensity profile of about 100 A-lines in a region of interest after correction for the effect of beam geometry, using a single scattering model. The average scleral attenuation coefficient was 4.13 ± 1.42 mm-1 with an age-related decrease that was near the threshold for statistical significance (p = 0.053). The average ciliary muscle attenuation coefficient was 1.72 ± 0.88 mm-1, but this value may be an underestimation due to contributions from multiple scattering. Overall, the results suggest that inter-individual variations in scleral attenuation contribute to variability in the quality of transscleral OCT images of the ciliary muscle and the outcome of transscleral laser therapies.
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Affiliation(s)
- Gabrielle Monterano Mesquita
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Disha Patel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Yu-Cherng Chang
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Florence Cabot
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Marco Ruggeri
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Sonia H. Yoo
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Arthur Ho
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
- Brien Holden Vision Institute, Sydney, NSW 2052, Australia
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW 2033, Australia
| | - Jean-Marie A. Parel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
- Brien Holden Vision Institute, Sydney, NSW 2052, Australia
| | - Fabrice Manns
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
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Review of the application of the open-source software CilOCT for semi-automatic segmentation and analysis of the ciliary muscle in OCT images. PLoS One 2020; 15:e0234330. [PMID: 32516331 PMCID: PMC7282635 DOI: 10.1371/journal.pone.0234330] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/22/2020] [Indexed: 11/25/2022] Open
Abstract
Presbyopia and myopia research shows a growing interest in ciliary muscle biometry using optical coherence tomography (OCT). Until now, segmentation of the ciliary muscle is often performed manually using either custom-developed programs or image processing software. Here we present a novel software for semi-automatic segmentation of the ciliary muscle. It provides direct import of OCT images in DICOM format, a standardized procedure for segmentation, image distortion correction, the export of anatomical ciliary muscle landmarks, like ciliary muscle apex and scleral spur, as well as a continuous thickness profile of the ciliary muscle as a novel way of analysis. All processing steps are stored as XML files, fostering documentation and reproducibility of research through the possibility of replicating the analysis. Additionally, CilOCT supports batch processing for the automated analysis of large numbers of images and the respective data export to tabulated text files based on the stored XML files. CilOCT was successfully applied in several studies and their results will be summarized in this paper.
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Wagner S, Zrenner E, Strasser T. Ciliary muscle thickness profiles derived from optical coherence tomography images. BIOMEDICAL OPTICS EXPRESS 2018; 9:5100-5114. [PMID: 30319924 PMCID: PMC6179398 DOI: 10.1364/boe.9.005100] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/18/2018] [Accepted: 09/18/2018] [Indexed: 05/09/2023]
Abstract
The purpose of this study was to provide an in-depth analysis of the ciliary muscle's (CM) morphological changes during accommodation by evaluating CM thickness (CMT) profiles. The CM of 15 near-emmetropic subjects (age 20-39) was imaged via optical coherence tomography (OCT) during far (0 D) and near vision (3 D). A custom-made Java-based program was used for semi-automatic CM segmentation and thickness measurements. CMT profiles were generated to determine regions of the largest shape changes. The results revealed on average a thinning within the first 0.25 mm and a thickening from 0.36 to 1.48 mm posterior to scleral spur when accommodating from 0 to 3 D. In contrast to previous analyses, this method offers pixel-wise reconstruction of CM shapes and quantification of accommodative change across the entire muscle boundary.
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Affiliation(s)
- Sandra Wagner
- Institute for Ophthalmic Research, Eberhard Karls University Tuebingen, Elfriede-Aulhorn-Str. 7, 72076 Tuebingen, Germany
| | - Eberhart Zrenner
- Institute for Ophthalmic Research, Eberhard Karls University Tuebingen, Elfriede-Aulhorn-Str. 7, 72076 Tuebingen, Germany
- Werner Reichardt Centre for Integrative Neuroscience (CIN), Otfried-Mueller-Str. 25, 72076 Tuebingen, Germany
| | - Torsten Strasser
- Institute for Ophthalmic Research, Eberhard Karls University Tuebingen, Elfriede-Aulhorn-Str. 7, 72076 Tuebingen, Germany
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