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Gan L, Tang F, Liao J, Xiang H, Tang L. Modified superior bleb needling of rare hypertrophic bleb after trabeculectomy: A case series. Eur J Ophthalmol 2024:11206721241256689. [PMID: 38767136 DOI: 10.1177/11206721241256689] [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: 05/22/2024]
Abstract
BACKGROUND Hypertrophic bleb is a rare complication of glaucoma filtration surgery characterized by an elevated bleb extended through the nasal 180 degrees of the eye and usually with a normal IOP. Currently, there is little experience and no existing standardized treatment. We describe a new method called modified superior bleb needling and evaluate the clinical outcomes in affected eyes. METHODS In this retrospective, consecutive interventional case series, patients who developed hypertrophic blebs after trabeculectomy from November 2015 to August 2020 at West China Hospital were enrolled. We innovatively adopted a modified superior bleb needling to allow aqueous humor to outflow into the superior subconjunctival space. Repeat needlings were performed if necessary. The technical and clinical success rate and complications were reported. RESULTS At the time of the last follow-up, complete success was achieved in 8/10 patients, qualified success was achieved in 9/10 patients, and failure was achieved in 1/10 patients. Eight patients had a low filtering bleb and IOP ≤21 mmHg. There was no statistically significant difference between the preneedling and postneedling IOP (p > 0.05). CONCLUSION Modified superior bleb needling is effective for hypertrophic blebs after trabeculectomy, and there was no significant impact on anterior chamber depth or IOP, making it a viable or preferred alternative option. It is worthy of further study and wider usage.
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Affiliation(s)
- Lu Gan
- Ophthalmology, Sichuan University, West China Hospital, ChengDu, China
- Ophthalmology, Sichuan University, West China School of Public Health and West China Fourth Hospital, ChengDu, China
| | - Fei Tang
- Ophthalmology, ShangjinNanfu Hospital, Chengdu, China
| | - Jinying Liao
- Ophthalmology, Sichuan University, West China Hospital, ChengDu, China
| | - Haotian Xiang
- Ophthalmology, Sichuan University, West China Hospital, ChengDu, China
| | - Li Tang
- Ophthalmology, Sichuan University, West China Hospital, ChengDu, China
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2
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Gan L, Wang L, Chen J, Tang L. Complications of XEN gel stent implantation for the treatment of glaucoma: a systematic review. Front Med (Lausanne) 2024; 11:1360051. [PMID: 38770050 PMCID: PMC11102958 DOI: 10.3389/fmed.2024.1360051] [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: 12/22/2023] [Accepted: 04/22/2024] [Indexed: 05/22/2024] Open
Abstract
Aim This study was aimed to summarize the complications and their management associated with XEN gel stent implantation. Methods A systematic review of literature was conducted using Medline (via PubMed), EMBASE, the Cochrane Library databases, and China National Knowledge Infrastructure, from their inception to February 1, 2024. Results A total of 48 studies published between 2017 and 2024 were identified and included in the systematic review, including 16 original studies (retrospective or prospective clinical studies), 28 case reports, and 4 case series, which followed patients for up to 5 years. Early postoperative complications of XEN gel stent implantation include hypotony maculopathy (1.9-4.6%), occlusion (3.9-8.8%), suprachoroidal hemorrhage (SCH), choroidal detachment (0-15%), conjunctival erosion, and exposure of the XEN gel stent (1.1-2.3%), wound and bleb leaks (2.1%) and malignant glaucoma (MG) (2.2%). Mid-postoperative complications of XEN gel stent implantation included migration of XEN (1.5%), ptosis (1.2%), endophthalmitis (0.4-3%), macular edema (1.5-4.3%), hypertrophic bleb (8.8%) and subconjunctival XEN gel stent fragmentation (reported in 2 cases). Late postoperative complications reported in cases included spontaneous dislocation and intraocular degradation. Conclusion XEN gel stent implantation is a minimally invasive glaucoma surgery (MIGS) procedure for glaucoma, known for its potential to minimize tissue damage and reduce surgical duration. However, it is crucial to note that despite these advantages, there remains a risk of severe complications, including endophthalmitis, SCH, and MG. Therefore, postoperative follow-up and early recognition of severe complications are essential for surgical management.
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Affiliation(s)
- Lu Gan
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Department of Ophthalmology, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Lixiang Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Jun Chen
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Li Tang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
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3
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Gong P, Tang X, Chen J, You H, Wang Y, Yu PK, Yu DY, Cense B. Deep learning-based label-free imaging of lymphatics and aqueous veins in the eye using optical coherence tomography. Sci Rep 2024; 14:6126. [PMID: 38480842 PMCID: PMC10937663 DOI: 10.1038/s41598-024-56273-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 03/04/2024] [Indexed: 03/17/2024] Open
Abstract
We demonstrate an adaptation of deep learning for label-free imaging of the micro-scale lymphatic vessels and aqueous veins in the eye using optical coherence tomography (OCT). The proposed deep learning-based OCT lymphangiography (DL-OCTL) method was trained, validated and tested, using OCT scans (23 volumetric scans comprising 19,736 B-scans) from 11 fresh ex vivo porcine eyes with the corresponding vessel labels generated by a conventional OCT lymphangiography (OCTL) method based on thresholding with attenuation compensation. Compared to conventional OCTL, the DL-OCTL method demonstrates comparable results for imaging lymphatics and aqueous veins in the eye, with an Intersection over Union value of 0.79 ± 0.071 (mean ± standard deviation). In addition, DL-OCTL mitigates the imaging artifacts in conventional OCTL where the OCT signal modelling was corrupted by the tissue heterogeneity, provides ~ 10 times faster processing based on a rough comparison and does not require OCT-related knowledge for correct implementation as in conventional OCTL. With these favorable features, DL-OCTL promises to improve the practicality of OCTL for label-free imaging of lymphatics and aqueous veins for preclinical and clinical imaging applications.
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Affiliation(s)
- Peijun Gong
- Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, 310027, China.
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, 6009, Australia.
| | - Xiaolan Tang
- School of Software Engineering, South China University of Technology, Guangzhou, 510006, China
- Key Laboratory of Big Data and Intelligent Robot (SCUT), Ministry of Education, Guangzhou, 510006, China
| | - Junying Chen
- School of Software Engineering, South China University of Technology, Guangzhou, 510006, China.
- Key Laboratory of Big Data and Intelligent Robot (SCUT), Ministry of Education, Guangzhou, 510006, China.
| | - Haijun You
- School of Software Engineering, South China University of Technology, Guangzhou, 510006, China
- Key Laboratory of Big Data and Intelligent Robot (SCUT), Ministry of Education, Guangzhou, 510006, China
| | - Yuxing Wang
- Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, 310027, China
| | - Paula K Yu
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, 6009, Australia
- Lions Eye Institute, Nedlands, WA, 6009, Australia
| | - Dao-Yi Yu
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, 6009, Australia
- Lions Eye Institute, Nedlands, WA, 6009, Australia
| | - Barry Cense
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, 6009, Australia
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
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4
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Lee JY, Strohmaier CA, Akiyama G, Saraswathy S, Yoo C, Kim YY, Hong YK, Huang AS. Bleb-related Porcine Lymphatic Outflow is Greater from Subconjunctival compared to Subtenon Blebs. J Curr Glaucoma Pract 2022; 16:144-151. [PMID: 36793268 PMCID: PMC9905879 DOI: 10.5005/jp-journals-10078-1382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 07/20/2022] [Indexed: 01/25/2023] Open
Abstract
Aim Understanding the mechanism of fluid outflow by comparing the subconjunctival and subtenon spaces can lead to improved ocular therapeutics. The purpose of the current study is to evaluate subconjunctival vs subtenon lymphatic outflow by creating tracer-filled blebs in each location. Methods Porcine (n = 20) eyes received subconjunctival or subtenon injection(s) of fixable and fluorescent dextrans. Blebs were angiographically imaged using a Heidelberg Spectralis ([Heidelberg Retina Angiograph] HRA + OCT; Heidelberg Engineering) and bleb-related lymphatic outflow pathways were counted. Optical coherence tomography (OCT) imaging of these pathways was used to assess structural lumens and the presence of valve-like structures. Furthermore, a comparison between tracer injection locations (superior/inferior/temporal/nasal) was made. Histologic analyses for subconjunctival and subtenon outflow pathways were performed, to confirm tracer co-localization with molecular lymphatic markers. Results Subconjunctival blebs demonstrated a greater number of lymphatic outflow pathways compared to subtenon blebs in every quadrant [superior: 6.10 ± 1.18 (subconjunctival) vs 0.50 ± 0.27 (subtenon); temporal: 2.30 ± 0.40 vs 0.10 ± 0.10; nasal: 5.30 ± 0.60 vs 0.30 ± 0.21; inferior: 6.00 ±1.29 vs 0.1 ± 0.1; all comparisons p < 0.001]. For subconjunctival blebs, the temporal quadrant showed fewer lymphatic outflow pathways compared to the nasal side (p = 0.005). Discussion Subconjunctival blebs accessed greater lymphatic outflow compared to subtenon blebs. Furthermore, regional differences existed, with fewer lymphatic vessels temporal than at the other locations. Clinical significance Aqueous humor drainage after glaucoma surgery is incompletely understood. The present manuscript adds to our understanding of how lymphatics might influence filtration bleb function. How to cite this article Lee JY, Strohmaier CA, Akiyama G, et al. Bleb-related Porcine Lymphatic Outflow Is Greater from Subconjunctival compared to Subtenon Blebs. J Curr Glaucoma Pract 2022;16(3):144-151.
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Affiliation(s)
- Jong Yeon Lee
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA; Department of Ophthalmology, Gachon University College of Medicine, Gil Medical Center, Incheon, Korea
| | - Clemens Adolf Strohmaier
- Department of Ophthalmology, Johannes Kepler University, Linz, Austria; The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, Hamilton Glaucoma Center, University of California, San Diego, California
| | | | - Sindhu Saraswathy
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Chungkwon Yoo
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Yong Yeon Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Young-Kwon Hong
- Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Alex S Huang
- Alfred Vogt Endowed Chair in Ophthalmology, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, Hamilton Glaucoma Center, University of California, San Diego, California, USA
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Peil J, Bock F, Kiefer F, Schmidt R, Heindl LM, Cursiefen C, Schlereth SL. New Therapeutic Approaches for Conjunctival Melanoma-What We Know So Far and Where Therapy Is Potentially Heading: Focus on Lymphatic Vessels and Dendritic Cells. Int J Mol Sci 2022; 23:1478. [PMID: 35163401 PMCID: PMC8835854 DOI: 10.3390/ijms23031478] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/21/2022] [Accepted: 01/24/2022] [Indexed: 11/25/2022] Open
Abstract
Conjunctival melanoma (CM) accounts for 5% of all ocular melanomas and arises from malignantly transformed melanocytes in the conjunctival epithelium. Current therapies using surgical excision in combination with chemo- or cryotherapy still have high rates for recurrences and metastatic disease. Lately, novel signal transduction-targeted and immune checkpoint inhibitors like cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, programmed cell death protein-1 (PD-1) receptor inhibitors, BRAF- or MEK-inhibitors for systemic treatment of melanoma have improved the outcome even for unresectable cutaneous melanoma, improving patient survival dramatically. The use of these therapies is now also recommended for CM; however, the immunological background of CM is barely known, underlining the need for research to better understand the immunological basics when treating CM patients with immunomodulatory therapies. Immune checkpoint inhibitors activate tumor defense by interrupting inhibitory interactions between tumor cells and T lymphocytes at the so-called checkpoints. The tumor cells exploit these inhibitory targets on T-cells that are usually used by dendritic cells (DCs). DCs are antigen-presenting cells at the forefront of immune response induction. They contribute to immune tolerance and immune defense but in the case of tumor development, immune tolerance is often prevalent. Enhancing the immune response via DCs, interfering with the lymphatic pathways during immune cell migration and tumor development and specifically targeting tumor cells is a major therapeutic opportunity for many tumor entities including CM. This review summarizes the current knowledge on the function of lymphatic vessels in tumor growth and immune cell transport and continues to compare DC subsets in CM with related melanomas, such as cutaneous melanoma and mucosal melanoma.
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Affiliation(s)
- Jennifer Peil
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; (J.P.); (F.B.); (L.M.H.); (C.C.)
| | - Felix Bock
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; (J.P.); (F.B.); (L.M.H.); (C.C.)
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50937 Cologne, Germany
| | - Friedemann Kiefer
- European Institute for Molecular Imaging (EIMI), University of Münster, 48149 Münster, Germany;
| | - Rebecca Schmidt
- Department of Oral, Maxillofacial and Plastic Facial Surgery, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, 40225 Düsseldorf, Germany;
| | - Ludwig M. Heindl
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; (J.P.); (F.B.); (L.M.H.); (C.C.)
| | - Claus Cursiefen
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; (J.P.); (F.B.); (L.M.H.); (C.C.)
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50937 Cologne, Germany
| | - Simona L. Schlereth
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany; (J.P.); (F.B.); (L.M.H.); (C.C.)
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50937 Cologne, Germany
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Lee JY, Heilweil G, Le P, Saraswathy S, Hong YK, Girkin CA, Huang AS. Structural Confirmation of Lymphatic Outflow from Subconjunctival Blebs of Live Human Subjects. OPHTHALMOLOGY SCIENCE 2021; 1. [PMID: 35005679 PMCID: PMC8740887 DOI: 10.1016/j.xops.2021.100080] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Purpose To uncover the mechanism of subconjunctival outflow in humans. Design Cross-sectional study. Participants Fifteen patients receiving subconjunctival anesthesia before intravitreal injection for routine clinical care. Methods Anterior segment (AS) OCT was performed in patients with various instances of conjunctival edema or subconjunctival fluid. Other patients received a subconjunctival mixture of 0.005% indocyanine green and 2% lidocaine. After subconjunctival injection of the tracer and anesthetic mixture, blebs and associated outflow pathways were imaged angiographically and the time for appearance was recorded. The pattern and structure of outflow pathways were studied using AS OCT. Angiographic and AS OCT results were compared with trabecular and conventional outflow imaging, which demonstrates veins. Main Outcome Measures Ocular surface lymphangiography and AS OCT images. Results Anterior segment OCT of the conjunctiva in a normal eye demonstrated thin nonedematous conjunctiva with absent intraconjunctival lumens or subconjunctival fluid. Patients with a history of trabeculectomy, subconjunctival drug injection, or chemosis demonstrated thickened conjunctiva and intraconjunctival luminal pathways that contained valve-like structures. Tracer-based studies in patients demonstrated blebs with irregular subconjunctival bleb-related outflow patterns that arose in a time-dependent fashion. These angiographic pathways were luminal on OCT, sausage shaped, and contained intraluminal valve-like structures. This was in contrast to trabecular and conventional outflow imaging, where pathways were classically Y-shaped, of even caliber, and lacked valve-like structures. Conclusions Outflow pathways were seen in patients with conjunctival edema and after subconjunctival tracer injection. These pathways were lymphatic based on pattern and structural study. Better understanding of bleb-related lymphatic outflow may lead to improved bleb-requiring glaucoma surgeries and subconjunctival drug delivery.
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Affiliation(s)
- Jong Yeon Lee
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, USA.,Department of Ophthalmology, Gachon University College of Medicine, Gil Medical Center, Incheon, Korea
| | - Gad Heilweil
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Phuc Le
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Sindhu Saraswathy
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Young-Kwon Hong
- Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Christopher A Girkin
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alex S Huang
- The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, CA, USA
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7
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Aqueous outflow channels and its lymphatic association: A review. Surv Ophthalmol 2021; 67:659-674. [PMID: 34656556 PMCID: PMC9008077 DOI: 10.1016/j.survophthal.2021.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 10/07/2021] [Accepted: 10/11/2021] [Indexed: 11/24/2022]
Abstract
The human eye has a unique immune architecture and behavior. While the conjunctiva is known to have a well-defined lymphatic drainage system, the cornea, sclera, and uveal tissues were historically considered "alymphatic" and thought to be immune privileged. The very fact that the aqueous outflow channels carry a clear fluid (aqueous humor) along the outflow pathway makes it hard to ignore its lymphatic-like characteristics. The development of novel lymphatic lineage markers and expression of these markers in aqueous outflow channels and improved imaging capabilities has sparked a renewed interest in the study of ocular lymphatics. Ophthalmic lymphatic research has had a directional shift over the last decade, offering an exciting new physiological platform that needs further in-depth understanding. The evidence of a presence of distinct lymphatic channels in the human ciliary body is gaining significant traction. The uveolymphatic pathway is an alternative new route for aqueous outflow and adds a new dimension to pathophysiology and management of glaucoma. Developing novel animal models, markers, and non-invasive imaging tools to delineate the core anatomical structure and physiological functions may help pave some crucial pathways to understand disease pathophysiology and help develop novel targeted therapeutic approaches for glaucoma.
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8
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Polomska AK, Proulx ST. Imaging technology of the lymphatic system. Adv Drug Deliv Rev 2021; 170:294-311. [PMID: 32891679 DOI: 10.1016/j.addr.2020.08.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/16/2020] [Accepted: 08/31/2020] [Indexed: 12/17/2022]
Abstract
The lymphatic system plays critical roles in tissue fluid homeostasis and immunity and has been implicated in the development of many different pathologies, ranging from lymphedema, the spread of cancer to chronic inflammation. In this review, we first summarize the state-of-the-art of lymphatic imaging in the clinic and the advantages and disadvantages of these existing techniques. We then detail recent progress on imaging technology, including advancements in tracer design and injection methods, that have allowed visualization of lymphatic vessels with excellent spatial and temporal resolution in preclinical models. Finally, we describe the different approaches to quantifying lymphatic function that are being developed and discuss some emerging topics for lymphatic imaging in the clinic. Continued advancements in lymphatic imaging technology will be critical for the optimization of diagnostic methods for lymphatic disorders and the evaluation of novel therapies targeting the lymphatic system.
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Affiliation(s)
- Anna K Polomska
- ETH Zürich, Institute of Pharmaceutical Sciences, Vladimir-Prelog Weg 1-5/10, 8093 Zürich, Switzerland
| | - Steven T Proulx
- University of Bern, Theodor Kocher Institute, Freiestrasse 1, 3012 Bern, Switzerland.
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9
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Lee JY, Akiyama G, Saraswathy S, Xie X, Pan X, Hong YK, Huang AS. Aqueous humour outflow imaging: seeing is believing. Eye (Lond) 2020; 35:202-215. [PMID: 33060830 DOI: 10.1038/s41433-020-01215-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/27/2020] [Accepted: 09/29/2020] [Indexed: 12/22/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the primary risk factor for blindness in glaucoma. IOP is determined by many factors including aqueous humour production and aqueous humour outflow (AHO), where AHO disturbance represents the primary cause of increased IOP. With the recent development of new IOP lowering drugs and Minimally Invasive Glaucoma Surgeries (MIGS), renewed interest has arisen in shedding light on not only how but where AHO is occurring for the trabecular/conventional, uveoscleral/unconventional, and subconjunctival outflow pathways. Historical studies critical to understanding outflow anatomy will be presented, leading to the development of modern imaging methods. New biological behaviours uncovered by modern imaging methods will be discussed with relevance to glaucoma therapies emphasized.
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Affiliation(s)
- Jong Yeon Lee
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Department of Ophthalmology, Gachon University, College of Medicine, Gil Medical Center, Incheon, Korea
| | - Goichi Akiyama
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Jikei School of Medicine, Tokyo, Japan.,Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Sindhu Saraswathy
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Xiaobin Xie
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Eye Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaojing Pan
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Qindao Eye Hospital of Shandong First Medical University, Shandong Eye Institute, Qindao, China
| | - Young-Kwon Hong
- Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Alex S Huang
- Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
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Akiyama G, Saraswathy S, Bogarin T, Pan X, Barron E, Wong TT, Kaneko MK, Kato Y, Hong Y, Huang AS. Functional, structural, and molecular identification of lymphatic outflow from subconjunctival blebs. Exp Eye Res 2020; 196:108049. [PMID: 32387381 PMCID: PMC7328765 DOI: 10.1016/j.exer.2020.108049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/05/2020] [Accepted: 04/27/2020] [Indexed: 01/26/2023]
Abstract
The purpose of this study is to evaluate outflow pathways from subconjunctival blebs and to identify their identity. Post-mortem porcine (n = 20), human (n = 1), and bovine (n = 1) eyes were acquired, and tracers (fluorescein, indocyanine green, or fixable/fluorescent dextrans) were injected into the subconjunctival space to create raised blebs where outflow pathways were visualized qualitatively and quantitatively. Rodents with fluorescent reporter transgenes were imaged for structural comparison. Concurrent optical coherence tomography (OCT) was obtained to study the structural nature of these pathways. Using fixable/fluorescent dextrans, tracers were trapped to the bleb outflow pathway lumen walls for histological visualization and molecular identification using immunofluorescence against lymphatic and blood vessel markers. Bleb outflow pathways could be observed using all tracers in all species. Quantitative analysis showed that the nasal quadrant had more bleb-related outflow pathways compared to the temporal quadrant (nasal: 1.9±0.3 pathways vs. temporal: 0.7±0.2 pathways; p = 0.003). However, not all blebs resulted in an outflow pathway (0-pathways = 18.2%; 1-pathway = 36.4%; 2-pathways = 38.6%; and 3-pathways = 6.8%). Outflow signal was validated as true luminal pathways using optical coherence tomography and histology. Bicuspid valves were identified in the direction of flow in porcine eyes. Immunofluorescence of labeled pathways demonstrated a lymphatic (Prox-1 and podoplanin) but not a blood vessel (CD31) identity. Therefore, subconjunctival bleb outflow occurs in discrete luminal pathways. They are lymphatic as assessed by structural identification of valves and molecular identification of lymphatic markers. Better understanding of lymphatic outflow may lead to improved eye care for glaucoma surgery and ocular drug delivery.
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Affiliation(s)
- Goichi Akiyama
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Jikei School of Medicine, Tokyo, Japan
| | - Sindhu Saraswathy
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Thania Bogarin
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Xiaojing Pan
- Qingdao Eye Hospital, Shandong Eye Institute, Shandong First Medical University, Qingdao, China
| | - Ernesto Barron
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Tina T Wong
- Singapore National Eye Center and Singapore Research Institute, Singapore, Singapore
| | - Mika K Kaneko
- Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Yukinari Kato
- Tohoku University Graduate School of Medicine, Miyagi, Japan; New Industry Creation Hatchery Center, Tohoku University, Miyagi, Japan
| | - Young Hong
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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Gong P, Almasian M, van Soest G, de Bruin DM, van Leeuwen TG, Sampson DD, Faber DJ. Parametric imaging of attenuation by optical coherence tomography: review of models, methods, and clinical translation. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-34. [PMID: 32246615 PMCID: PMC7118361 DOI: 10.1117/1.jbo.25.4.040901] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 02/28/2020] [Indexed: 05/07/2023]
Abstract
SIGNIFICANCE Optical coherence tomography (OCT) provides cross-sectional and volumetric images of backscattering from biological tissue that reveal the tissue morphology. The strength of the scattering, characterized by an attenuation coefficient, represents an alternative and complementary tissue optical property, which can be characterized by parametric imaging of the OCT attenuation coefficient. Over the last 15 years, a multitude of studies have been reported seeking to advance methods to determine the OCT attenuation coefficient and developing them toward clinical applications. AIM Our review provides an overview of the main models and methods, their assumptions and applicability, together with a survey of preclinical and clinical demonstrations and their translation potential. RESULTS The use of the attenuation coefficient, particularly when presented in the form of parametric en face images, is shown to be applicable in various medical fields. Most studies show the promise of the OCT attenuation coefficient in differentiating between tissues of clinical interest but vary widely in approach. CONCLUSIONS As a future step, a consensus on the model and method used for the determination of the attenuation coefficient is an important precursor to large-scale studies. With our review, we hope to provide a basis for discussion toward establishing this consensus.
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Affiliation(s)
- Peijun Gong
- The University of Western Australia, Department of Electrical, Electronic and Computer Engineering, Optical+Biomedical Engineering Laboratory, Perth, Western Australia, Australia
- Address all correspondence to Peijun Gong, E-mail:
| | - Mitra Almasian
- University of Amsterdam, Amsterdam University Medical Centers, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
| | - Gijs van Soest
- Erasmus MC, University Medical Center Rotterdam, Department of Cardiology, Rotterdam, The Netherlands
| | - Daniel M. de Bruin
- University of Amsterdam, Amsterdam University Medical Centers, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
| | - Ton G. van Leeuwen
- University of Amsterdam, Amsterdam University Medical Centers, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
| | - David D. Sampson
- The University of Western Australia, Department of Electrical, Electronic and Computer Engineering, Optical+Biomedical Engineering Laboratory, Perth, Western Australia, Australia
- University of Surrey, Surrey Biophotonics, Guildford, Surrey, United Kingdom
| | - Dirk J. Faber
- University of Amsterdam, Amsterdam University Medical Centers, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
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Si P, Honkala A, de la Zerda A, Smith BR. Optical Microscopy and Coherence Tomography of Cancer in Living Subjects. Trends Cancer 2020; 6:205-222. [PMID: 32101724 DOI: 10.1016/j.trecan.2020.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 01/05/2020] [Accepted: 01/07/2020] [Indexed: 12/16/2022]
Abstract
Intravital microscopy (IVM) and optical coherency tomography (OCT) are two powerful optical imaging tools that allow visualization of dynamic biological activities in living subjects with subcellular resolutions. Recent advances in labeling and label-free techniques empower IVM and OCT for a wide range of preclinical and clinical cancer imaging, providing profound insights into the complex physiological, cellular, and molecular behaviors of tumors. Preclinical IVM and OCT have elucidated many otherwise inscrutable aspects of cancer biology, while clinical applications of IVM and OCT are revolutionizing cancer diagnosis and therapies. We review important progress in the fields of IVM and OCT for cancer imaging in living subjects, highlighting key technological developments and their emerging applications in fundamental cancer biology research and clinical oncology investigation.
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Affiliation(s)
- Peng Si
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA
| | - Alexander Honkala
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Adam de la Zerda
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA; The Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| | - Bryan Ronain Smith
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Department of Biomedical Engineering and Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, USA.
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Demidov V, Matveev LA, Demidova O, Matveyev AL, Zaitsev VY, Flueraru C, Vitkin IA. Analysis of low-scattering regions in optical coherence tomography: applications to neurography and lymphangiography. BIOMEDICAL OPTICS EXPRESS 2019; 10:4207-4219. [PMID: 31453005 PMCID: PMC6701530 DOI: 10.1364/boe.10.004207] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/24/2019] [Accepted: 07/17/2019] [Indexed: 05/19/2023]
Abstract
Analysis of semi-transparent low scattering biological structures in optical coherence tomography (OCT) has been actively pursued in the context of lymphatic imaging, with most approaches relying on the relative absence of signal as a means of detection. Here we present an alternate methodology based on spatial speckle statistics, utilizing the similarity of a distribution of given voxel intensities to the power distribution function of pure noise, to visualize the low-scattering biological structures of interest. In a human tumor xenograft murine model, we show that these correspond to lymphatic vessels and nerves; extensive histopathologic validation studies are reported to unequivocally establish this correspondence. The emerging possibility of OCT lymphangiography and neurography is novel and potentially impactful (especially the latter), although further methodology refinement is needed to distinguish between the visualized lymphatics and nerves.
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Affiliation(s)
- Valentin Demidov
- Department of Medical Biophysics, University of Toronto, 101 College St., Toronto, M5G 1L7, Canada
| | - Lev A. Matveev
- Institute of Applied Physics Russian Academy of Sciences, 46 Ulyanov Street, Nizhniy Novgorod, 603950, Russia
| | - Olga Demidova
- Department of Arts and Science, Seneca College, 1750 Finch Avenue East, Toronto, M2J 2X5, Canada
| | - Alexander L. Matveyev
- Institute of Applied Physics Russian Academy of Sciences, 46 Ulyanov Street, Nizhniy Novgorod, 603950, Russia
| | - Vladimir Y. Zaitsev
- Institute of Applied Physics Russian Academy of Sciences, 46 Ulyanov Street, Nizhniy Novgorod, 603950, Russia
| | - Costel Flueraru
- National Research Council Canada, Information Communication Technology, 1200 Montreal Rd, Ottawa, K1A0R6, Canada
| | - I. Alex Vitkin
- Department of Medical Biophysics, University of Toronto, 101 College St., Toronto, M5G 1L7, Canada
- University Health Network, Princess Margaret Cancer Centre, 610 University Ave, Toronto, M5G 2C1, Canada
- University of Toronto, Department of Radiation Oncology, 150 College St, Toronto, M5S 3E2, Canada
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Xie X, Akiyama G, Bogarin T, Saraswathy S, Huang AS. Visual Assessment of Aqueous Humor Outflow. Asia Pac J Ophthalmol (Phila) 2019; 8:126-134. [PMID: 30916496 PMCID: PMC7028348 DOI: 10.22608/apo.201911] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In the past decade, many new pharmacological and surgical treatments have become available to lower intraocular pressure (IOP) for glaucoma. The majority of these options have targeted improving aqueous humor outflow (AHO). At the same time, in addition to new treatments, research advances in AHO assessment have led to the development of new tools to structurally assess AHO pathways and to visualize where aqueous is flowing in the eye. These new imaging modalities have uncovered novel AHO observations that challenge traditional AHO concepts. New behaviors including segmental, pulsatile, and dynamic AHO may have relevance to the disease and the level of therapeutic response for IOP-lowering treatments. By better understanding the regulation of segmental, pulsatile, and dynamic AHO, it may be possible to find new and innovative treatments for glaucoma aiming at these new AHO behaviors.
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Affiliation(s)
- Xiaobin Xie
- From the Eye Hospital of China Academy of Chinese Medical Sciences, Beijing, China; and UCLA Department of Ophthalmology, Doheny Eye Institute, Los Angeles, CA, United States
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