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Ye S, Bao C, Chen Y, Shen M, Lu F, Zhang S, Zhu D. Identification of Peripheral Anterior Synechia by Corneal Deformation Using Air-Puff Dynamic Anterior Segment Optical Coherence Tomography. Front Bioeng Biotechnol 2022; 10:856531. [PMID: 35433648 PMCID: PMC9011042 DOI: 10.3389/fbioe.2022.856531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 03/07/2022] [Indexed: 11/13/2022] Open
Abstract
Indentation gonioscopy is commonly used in the clinic to evaluate peripheral anterior synechia (PAS) of angle closure glaucoma (ACG). The examination requires contacting with the cornea, resulting in an uncomfortable feeling for patients, and it only provides qualitative outcomes which may be affected by subjective judgment of the clinicians. Previous studies had reported to identify the presence of PAS by measuring the changes of morphological parameters of the anterior chamber angle (ACA) under the pupillary light reflex, by anterior segment optical coherence tomography (AS-OCT). However, this method was invalid for some subjects who had low sensitiveness to light. This article describes an air-puff dynamic anterior segment optical coherence tomography (DAS-OCT) system that can evaluate the presence of PAS in a non-contact approach. The peripheral cornea is deformed by an air puff jetted from the DAS-OCT, causing a transfer of force to the ACA, just as how indentation gonioscopy works. The dynamic changes of the ACA before and after the air puff are recorded by OCT. Ten eyes of normal subjects were enrolled in this study to validate the repeatability and availability of the measurements. Then, ten samples of the ACA from five subjects with ACG were recruited and were assigned into two groups, the non PAS group (NPAS) and PAS group, according to the results of gonioscopy. The ACA structural parameters including the angle opening distance at 750 μm to the scleral spur (AOD750) and the trabecular-iris space area at 750 μm anterior to the scleral spur (TISA750) were then calculated automatically by a custom-written algorithm. The intraclass correlation coefficient (ICC) of measured parameters was all above 0.85 for normal subjects, exhibiting good repeatability. For patients, both parameters showed significant differences between the two groups after the air puff, while no differences were observed before the air puff. AOD750dif and TISA750dif between two groups showed more significant differences, indicating that they could be used as indicators to identify the presence of PAS. In conclusion, the DAS-OCT system proposed in this study is demonstrated effective to identify the presence of PAS by measuring the changes of the ACA via a noncontact approach. It shows great potential for applications in guidance for diagnosis of angle closure glaucoma.
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Affiliation(s)
- Shuling Ye
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | | | - Yulei Chen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Meixiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Shaodan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- *Correspondence: Shaodan Zhang, ; Dexi Zhu,
| | - Dexi Zhu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
- *Correspondence: Shaodan Zhang, ; Dexi Zhu,
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Dai Y, Zhang S, Shen M, Jin Z, Zhou Y, Ye S, Bao C, Zhu D. Identification of peripheral anterior synechia with anterior segment optical coherence tomography. Graefes Arch Clin Exp Ophthalmol 2021; 259:2753-2759. [PMID: 33974133 DOI: 10.1007/s00417-021-05220-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 10/21/2022] Open
Abstract
PURPOSE To generate a model that evaluates the presence and extent of peripheral anterior synechia (PAS) based on anterior segment optical coherence tomography (AS-OCT). METHODS The extent of PAS involvement in the eyes of patients with angle closure was assessed by indentation gonioscopy, and the part of non-PAS and PAS were assigned into two groups (NPAS and PAS). Anterior chamber angles were then imaged by AS-OCT with light-emitting diode (LED) irradiation directly into the pupils, leading to pupillary constriction and increasing anterior chamber angle width. Parameters including the angle opening distance at 750 μm anterior to the scleral spur (AOD750) and trabecular-iris space area at 750 μm anterior to the scleral spur (TISA750) were then obtained. The differences before and after LED irradiation of AOD750 and TISA750 were calculated and used to generate a PAS model based on binary logistic regression. Validation data were then tested. RESULTS A total of 258 AS-OCT images in 14 eyes were assigned to the modeling data, and 120 were assigned to the validation data. There were no differences in AOD750 and TISA750 in the dark between NPAS and PAS (PAOD750 = 0.258, PTISA750 = 0.486), whereas after LED light exposure, TISA750light was larger in NPAS than in PAS (P = 0.047). The light-dark differences of both parameters showed significant differences between the two groups (PAOD750dif = 0.019, PTISA750dif < 0.001). The area under the curve of the model performance was 0.841, and the overall correct rate was 80.8% based on the validation data. CONCLUSIONS The present study demonstrates that the AS-OCT-based PAS model could be useful in the identifying of the presence of synechial angle closure and evaluating the extent of PAS in a single eye.
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Affiliation(s)
- Yingying Dai
- Zhejiang Industry and Trade Vocational College, Wenzhou, Zhejiang, China
| | - Shaodan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Meixiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zi Jin
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yuheng Zhou
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Shuling Ye
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Chenhong Bao
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Dexi Zhu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.
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Hao H, Zhao Y, Yan Q, Higashita R, Zhang J, Zhao Y, Xu Y, Li F, Zhang X, Liu J. Angle-closure assessment in anterior segment OCT images via deep learning. Med Image Anal 2021; 69:101956. [PMID: 33550010 DOI: 10.1016/j.media.2021.101956] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 12/29/2020] [Accepted: 12/31/2020] [Indexed: 10/22/2022]
Abstract
Precise characterization and analysis of anterior chamber angle (ACA) are of great importance in facilitating clinical examination and diagnosis of angle-closure disease. Currently, the gold standard for diagnostic angle assessment is observation of ACA by gonioscopy. However, gonioscopy requires direct contact between the gonioscope and patients' eye, which is uncomfortable for patients and may deform the ACA, leading to false results. To this end, in this paper, we explore a potential way for grading ACAs into open-, appositional- and synechial angles by Anterior Segment Optical Coherence Tomography (AS-OCT), rather than the conventional gonioscopic examination. The proposed classification schema can be beneficial to clinicians who seek to better understand the progression of the spectrum of angle-closure disease types, so as to further assist the assessment and required treatment at different stages of angle-closure disease. To be more specific, we first use an image alignment method to generate sequences of AS-OCT images. The ACA region is then localized automatically by segmenting an important biomarker - the iris - as this is a primary structural cue in identifying angle-closure disease. Finally, the AS-OCT images acquired in both dark and bright illumination conditions are fed into our Multi-Sequence Deep Network (MSDN) architecture, in which a convolutional neural network (CNN) module is applied to extract feature representations, and a novel ConvLSTM-TC module is employed to study the spatial state of these representations. In addition, a novel time-weighted cross-entropy loss (TC) is proposed to optimize the output of the ConvLSTM, and the extracted features are further aggregated for the purposes of classification. The proposed method is evaluated across 66 eyes, which include 1584 AS-OCT sequences, and a total of 16,896 images. The experimental results show that the proposed method outperforms existing state-of-the-art methods in applicability, effectiveness, and accuracy.
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Affiliation(s)
- Huaying Hao
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China; Glaucoma Artificial Intelligence Diagnosis and Imaging Analysis Joint Research Lab, Guangzhou & Ningbo, China
| | - Yitian Zhao
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China; Glaucoma Artificial Intelligence Diagnosis and Imaging Analysis Joint Research Lab, Guangzhou & Ningbo, China.
| | - Qifeng Yan
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China; Glaucoma Artificial Intelligence Diagnosis and Imaging Analysis Joint Research Lab, Guangzhou & Ningbo, China
| | - Risa Higashita
- Tomey Corporation, Nagoya, Japan; Department of Computer Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Jiong Zhang
- Laboratory of Neuro Imaging (LONI), Keck School of Medicine, University of SouthernCalifornia, Los Angeles, USA
| | - Yifan Zhao
- School of Aerospace, Transport and Manufacturing, Cranfield University, Bedford, UK
| | - Yanwu Xu
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China; Glaucoma Artificial Intelligence Diagnosis and Imaging Analysis Joint Research Lab, Guangzhou & Ningbo, China
| | - Fei Li
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou, China; Glaucoma Artificial Intelligence Diagnosis and Imaging Analysis Joint Research Lab, Guangzhou & Ningbo, China
| | - Xiulan Zhang
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou, China; Glaucoma Artificial Intelligence Diagnosis and Imaging Analysis Joint Research Lab, Guangzhou & Ningbo, China
| | - Jiang Liu
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China; Department of Computer Science and Engineering, Southern University of Science and Technology, Shenzhen, China; Glaucoma Artificial Intelligence Diagnosis and Imaging Analysis Joint Research Lab, Guangzhou & Ningbo, China.
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Voronin GV, Petrov SY, Volzhanin AV, El-Sangahawi AA, Avetisov KS. [Iris shape change and risk of anterior chamber angle closure]. Vestn Oftalmol 2020; 136:93-98. [PMID: 32366076 DOI: 10.17116/oftalma202013602193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Potential obstruction of the anterior chamber angle by iris root is a key factor of the pathogenesis of angle-closure glaucoma. Development and adoption of ultrasound biomicroscopy and optical coherence tomography in clinical practice have significantly expanded the capabilities of studying the structures of the anterior eye segment in terms of angle closure risk factors through improving visualization depth and quality of examination, including different variants of iris structure and potential changes of its shape in mydriasis. The article reviews various studies dedicated to the progression of primary angle-closure glaucoma and its dependence on the biometric parameters of the eye and changes in pupil size.
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Affiliation(s)
- G V Voronin
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.,Research Institute of Eye Diseases, Moscow, Russia
| | - S Yu Petrov
- Research Institute of Eye Diseases, Moscow, Russia
| | | | - A A El-Sangahawi
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - K S Avetisov
- Research Institute of Eye Diseases, Moscow, Russia
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Nakamine S, Sakai H, Arakaki Y, Yonahara M, Kaiya T. The effect of internal fixation lamp on anterior chamber angle width measured by anterior segment optical coherence tomography. Jpn J Ophthalmol 2017; 62:48-53. [PMID: 29094326 DOI: 10.1007/s10384-017-0533-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 07/30/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE To study the effect of the internal fixation lamp on anterior chamber width measured by anterior segment optical coherence tomography. METHODS In a prospective cross sectional observational study, consecutive 22 right eyes of 22 patients (4 men and 18 women) with suspected primary angle closure underwent swept source domain anterior segment optical coherence tomography (AS-OCT), (CASIA SS-1000, Tomey, Nagoya, Japan). Anterior chamber parameters of angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA) at 500 or 750 µm from scleral spur and pupil diameter were measured by AS-OCT in a three-dimensional mode in 4 quadrants (superior, inferior, temporal and nasal) in dark room setting both with and without internal fixation lamp. RESULTS Anterior segment parameters of AOD 500 in superior, inferior and temporal quadrants, AOD 750 at superior and nasal, TIA 500 at superior, and inferior and TIA 750 at superior and nasal, and ARA 500 or 750 at superior and inferior with internal fixation lamp were greater and the pupil diameter was significantly (all P < 0.05, paired t test) smaller than when measured without fixation lamp. CONCLUSIONS Internal fixation lamp of the anterior segment OCT makes the pupil constrict and angle wider. When using AS-OCT with usual setting with internal fixation lamp on with eyes in which the anterior chamber angle is narrow but open, it is recommended that the internal fixation lamp be turned off to ensure a clear indication as to whether the angle is open or closed in the dark.
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Affiliation(s)
- Sakari Nakamine
- Ophthalmology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.,Kaiya Eye Clinic, Hamamatsu, Shizuoka, 430-0903, Japan
| | - Hiroshi Sakai
- Ophthalmology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.
| | - Yoshikuni Arakaki
- Ophthalmology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan
| | - Michiko Yonahara
- Ophthalmology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan
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