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Chiang JCB, Tajbakhsh Z, Wolffsohn JS. The clinical impact of contact lens wear on neural structure and function of the cornea. Clin Exp Optom 2024:1-11. [PMID: 39250904 DOI: 10.1080/08164622.2024.2401511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 08/13/2024] [Accepted: 09/01/2024] [Indexed: 09/11/2024] Open
Abstract
Contact lens (CL) use is growing rapidly, with a current estimate of over 100 million wearers worldwide. Vast improvements in materials and designs have occurred over the past decades with advancements in the understanding of ocular surface health with CL wear. However, the potential impact of CL on neural structures and function of the ocular surface, particularly in relation to the richly innervated cornea, remain poorly understood. Problems with sensation such as CL discomfort and conditions that may be associated with lens wear including dry eye disease also remain pervasive. This narrative review discusses the findings from studies involving soft or rigid CL wearers, assessed with c linical techniques designed for examining the neural integrity of the cornea, namely in vivo confocal microscopy and esthesiometry. While the collective findings remain equivocal in terms of the changes in corneal nerve morphology and function with conventional CL wear, more specialised CLs, namely orthokeratology lenses, which mechanically manipulates the structure of the cornea seem to produce more prominent changes in nerve distribution and sensitivity reduction. Given the intricate relationship between neural and immune mechanisms in maintaining balanced ocular surface health, the potential links between these structural and functional findings with parainflammation and neuroinflammation, as well as clinical issues including CL discomfort and dry eye disease, are also explored.
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Affiliation(s)
| | - Zahra Tajbakhsh
- Department of Optometry, University of Western Australia, Crawley, Australia
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2
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Wu M, Fletcher EL, Chinnery HR, Downie LE, Mueller SN. Redefining our vision: an updated guide to the ocular immune system. Nat Rev Immunol 2024:10.1038/s41577-024-01064-y. [PMID: 39215057 DOI: 10.1038/s41577-024-01064-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2024] [Indexed: 09/04/2024]
Abstract
Balanced immune responses in the eyes are crucial to preserve vision. The ocular immune system has long been considered distinct, owing to the so-called 'immune privilege' of its component tissues. More recently, intravital imaging and transcriptomic techniques have reshaped scientific understanding of the ocular immune landscape, such as revealing the specialization of immune cell populations in the various tissues of the eye. As knowledge of the phenotypes of corneal and retinal immune cells has evolved, links to both the systemic immune system, and the central and peripheral nervous systems, have been identified. Using intravital imaging, T cells have recently been found to reside in, and actively patrol, the healthy human cornea. Disease-associated retinal microglia with links to retinal degeneration have also been identified. This Review provides an updated guide to the ocular immune system, highlighting current knowledge of the immune cells that are present in steady-state and specific diseased ocular tissues, as well as evidence for their relationship to systemic disease. In addition, we discuss emerging intravital imaging techniques that can be used to visualize immune cell morphology and dynamics in living human eyes and how these could be applied to advance understanding of the human immune system.
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Affiliation(s)
- Mengliang Wu
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Erica L Fletcher
- Department of Anatomy and Physiology, The University of Melbourne, Carlton, Victoria, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia.
- Lions Eye Institute, Nedlands, Western Australia, Australia.
- Optometry, The University of Western Australia, Crawley, Western Australia, Australia.
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia.
| | - Scott N Mueller
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
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3
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Ruiz-Lozano RE, Soifer M, Zemborain ZZ, Azar NS, Quiroga-Garza ME, Murillo S, Ma S, Komai S, Horne A, Khodor A, Rodriguez-Gutierrez LA, Stinnett SS, Farsiu S, Perez VL. Deep-learning based analysis of in-vivo confocal microscopy images of the subbasal corneal nerve plexus' inferior whorl in patients with neuropathic corneal pain and dry eye disease. Ocul Surf 2024; 34:241-246. [PMID: 39098764 DOI: 10.1016/j.jtos.2024.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 07/08/2024] [Accepted: 08/01/2024] [Indexed: 08/06/2024]
Abstract
PURPOSE To evaluate and compare subbasal corneal nerve parameters of the inferior whorl in patients with dry eye disease (DED), neuropathic corneal pain (NCP), and controls using a novel deep-learning-based algorithm to analyze in-vivo confocal microscopy (IVCM) images. METHODS Subbasal nerve plexus (SNP) images of the inferior whorl of patients with DED (n = 49, 77 eyes), NCP (n = 14, 24 eyes), and controls (n = 41, 59 eyes) were taken with IVCM and further analyzed using an open-source artificial intelligence (AI)-based algorithm previously developed by our group. This algorithm automatically segments nerves, immune cells, and neuromas in the SNP. The following parameters were compared between groups: nerve area density, average nerve thickness, average nerve segment tortuosity, junction point density, neuroma density, and immune cell density. RESULTS 160 eyes of 104 patients (63 % females), aged 56.8 ± 15.4 years, were included. The mean nerve area density was significantly lower in the DED (P = 0.012) and NCP (P < 0.001) groups compared to the control group. The junction point density was lower in the NCP group compared with control (P = 0.001) and DED (P = 0.004) groups. The immune cell density was higher in the DED group compared with controls (P < 0.001). CONCLUSIONS Deep-learning-based analysis of IVCM images of the corneal SNP inferior whorl distinguished a decreased mean nerve area density in patients with DED and NCP compared with controls and an increased immune cell density in patients with oGVHD- and SS-associated DED. These findings suggest that the inferior whorl could be used as landmark to distinguish between patients with DED and NCP.
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Affiliation(s)
- Raul E Ruiz-Lozano
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Matias Soifer
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Zane Z Zemborain
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Nadim S Azar
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA
| | - Manuel E Quiroga-Garza
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Sofia Murillo
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA
| | - Symon Ma
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Seitaro Komai
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Anupama Horne
- Department of Ophthalmology, Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Ali Khodor
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | | | - Sandra S Stinnett
- Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, NC, USA
| | - Sina Farsiu
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Ophthalmology, Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Victor L Perez
- Department of Ophthalmology, Foster Center for Ocular Immunology at Duke Eye Center, Duke University School of Medicine, Durham, NC, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA.
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4
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Rajan R, Makrai E, Lee JH, Singh S, Chinnery HR, Downie LE. Evaluating the efficacy and safety of therapeutic interventions for corneal neuropathy: A systematic review. Ocul Surf 2024; 33:80-98. [PMID: 38688453 DOI: 10.1016/j.jtos.2024.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/02/2024]
Abstract
Corneal neuropathy involves corneal nerve damage that disrupts ocular surface integrity, negatively impacting quality-of-life from pain and impaired vision. Any ocular or systemic condition that damages the trigeminal nerve can lead to corneal neuropathy. However, the condition currently does not have standardized diagnostic criteria or treatment protocols. The primary aim of this systematic review was to evaluate the efficacy and safety of interventions for treating corneal neuropathy. Randomized controlled trials (RCTs) that investigated corneal neuropathy treatments were eligible if the intervention(s) was compared to a placebo or active comparator. Comprehensive searches were conducted in Ovid MEDLINE, Ovid Embase and clinical trial registries from inception to July 2022. The Cochrane Risk-of-Bias 2 tool was used to assess study methodological quality. Certainty of the body of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Overall, 20 RCTs were included. Evaluated interventions comprised regenerative therapies (n = 6 studies), dietary supplements (n = 4), anti-glycemic agents (n = 3), combination therapy (n = 3), supportive therapies (n = 2) and systemic pain pharmacotherapies (n = 2). Nine RCTs were judged at high risk of bias for most outcomes. Definitions for corneal neuropathy in the populations varied substantially across studies, consistent with lack of consensus on diagnostic criteria. A diverse range of outcomes were quantified, likely reflecting absence of an agreed core outcome set. There was insufficient evidence to draw definitive conclusions on the efficacy or safety of any intervention. There was low or very low certainty evidence for several neuroregenerative agents and dietary supplements for improving corneal nerve fiber length in corneal neuropathy due to dry eye disease and diabetes. Low or very low certainty evidence was found for neuroregenerative therapies and dietary supplements not altering corneal immune cell density. This review identifies a need to standardize the clinical definition of corneal neuropathy and define a minimum set of core outcome measures. Together, this will provide a foundation for improved phenotyping of clinical populations in studies, and improve the capacity to synthesize data to inform evidence-based care. Protocol registration: PROSPERO ID: CRD42022348475.
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Affiliation(s)
- Rajni Rajan
- Department of Optometry and Vision Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Eve Makrai
- Department of Optometry and Vision Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Ji-Hyun Lee
- Department of Optometry and Vision Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Sumeer Singh
- Department of Optometry and Vision Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, University of Melbourne, Carlton, Victoria, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, University of Melbourne, Carlton, Victoria, Australia.
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5
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Di Girolamo N. Biologicals and Biomaterials for Corneal Regeneration and Vision Restoration in Limbal Stem Cell Deficiency. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2401763. [PMID: 38777343 DOI: 10.1002/adma.202401763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/15/2024] [Indexed: 05/25/2024]
Abstract
The mammalian cornea is decorated with stem cells bestowed with the life-long task of renewing the epithelium, provided they remain healthy, functional, and in sufficient numbers. If not, a debilitating disease known as limbal stem cell deficiency (LSCD) can develop causing blindness. Decades after the first stem cell (SC) therapy is devised to treat this condition, patients continue to suffer unacceptable failures. During this time, improvements to therapeutics have included identifying better markers to isolate robust SC populations and nurturing them on crudely modified biological or biomaterial scaffolds including human amniotic membrane, fibrin, and contact lenses, prior to their delivery. Researchers are now gathering information about the biomolecular and biomechanical properties of the corneal SC niche to decipher what biological and/or synthetic materials can be incorporated into these carriers. Advances in biomedical engineering including electrospinning and 3D bioprinting with surface functionalization and micropatterning, and self-assembly models, have generated a wealth of biocompatible, biodegradable, integrating scaffolds to choose from, some of which are being tested for their SC delivery capacity in the hope of improving clinical outcomes for patients with LSCD.
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Affiliation(s)
- Nick Di Girolamo
- Mechanisms of Disease and Translational Research, School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, 2052, Australia
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Pizzano M, Vereertbrugghen A, Cernutto A, Sabbione F, Keitelman IA, Shiromizu CM, Vera Aguilar D, Fuentes F, Giordano MN, Trevani AS, Galletti JG. Transient Receptor Potential Vanilloid-1 Channels Facilitate Axonal Degeneration of Corneal Sensory Nerves in Dry Eye. THE AMERICAN JOURNAL OF PATHOLOGY 2024; 194:810-827. [PMID: 38325553 DOI: 10.1016/j.ajpath.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/19/2023] [Accepted: 01/10/2024] [Indexed: 02/09/2024]
Abstract
Corneal nerve impairment contributes significantly to dry eye disease (DED) symptoms and is thought to be secondary to corneal epithelial damage. Transient receptor potential vanilloid-1 (TRPV1) channels abound in corneal nerve fibers and respond to inflammation-derived ligands, which increase in DED. TRPV1 overactivation promotes axonal degeneration in vitro, but whether it participates in DED-associated corneal nerve dysfunction is unknown. To explore this, DED was surgically induced in wild-type and TRPV1-knockout mice, which developed comparable corneal epithelial damage and reduced tear secretion. However, corneal mechanosensitivity decreased progressively only in wild-type DED mice. Sensitivity to capsaicin (TRPV1 agonist) increased in wild-type DED mice, and consistently, only this strain displayed DED-induced pain signs. Wild-type DED mice exhibited nerve degeneration throughout the corneal epithelium, whereas TRPV1-knockout DED mice only developed a reduction in the most superficial nerve endings that failed to propagate to the deeper subbasal corneal nerves. Pharmacologic TRPV1 blockade reproduced these findings in wild-type DED mice, whereas CD4+ T cells from both strains were equally pathogenic when transferred, ruling out a T-cell-mediated effect of TRPV1 deficiency. These data show that ocular desiccation triggers superficial corneal nerve damage in DED, but proximal propagation of axonal degeneration requires TRPV1 expression. Local inflammation sensitized TRPV1 channels, which increased ocular pain. Thus, ocular TRPV1 overactivation drives DED-associated corneal nerve impairment.
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Affiliation(s)
- Manuela Pizzano
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Alexia Vereertbrugghen
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Agostina Cernutto
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Florencia Sabbione
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Irene A Keitelman
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Carolina M Shiromizu
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Douglas Vera Aguilar
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Federico Fuentes
- Confocal Microscopy Unit, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Mirta N Giordano
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Analía S Trevani
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina
| | - Jeremías G Galletti
- Innate Immunity Laboratory, Institute of Experimental Medicine (CONICET/National Academy of Medicine of Buenos Aires), Buenos Aires, Argentina.
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Hossain P. Reducing the stress of corneal neuropathic pain: 'Pain without Stain'. Eye (Lond) 2024; 38:411. [PMID: 37726335 PMCID: PMC10858179 DOI: 10.1038/s41433-023-02750-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 09/12/2023] [Indexed: 09/21/2023] Open
Affiliation(s)
- Parwez Hossain
- Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
- Eye Unit, Southampton General Hospital, Tremona Road, Southampton, UK.
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8
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Toh CJL, Liu C, Lee IXY, Lin MTY, Tong L, Liu YC. Clinical associations of corneal neuromas with ocular surface diseases. Neural Regen Res 2024; 19:140-147. [PMID: 37488855 PMCID: PMC10479835 DOI: 10.4103/1673-5374.375308] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 07/26/2023] Open
Abstract
Corneal neuromas, also termed microneuromas, refer to microscopic, irregularly-shaped enlargements of terminal subbasal nerve endings at sites of nerve damage or injury. The formation of corneal neuromas results from damage to corneal nerves, such as following corneal pathology or corneal or intraocular surgeries. Initially, denervated areas of sensory nerve fibers become invaded by sprouts of intact sensory nerve fibers, and later injured axons regenerate and new sprouts called neuromas develop. In recent years, analysis of corneal nerve abnormalities including corneal neuromas which can be identified using in vivo confocal microscopy, a non-invasive imaging technique with microscopic resolution, has been used to evaluate corneal neuropathy and ocular surface dysfunction. Corneal neuromas have been shown to be associated with clinical symptoms of discomfort and dryness of eyes, and are a promising surrogate biomarker for ocular surface diseases, such as neuropathic corneal pain, dry eye disease, diabetic corneal neuropathy, neurotrophic keratopathy, Sjögren's syndrome, bullous keratopathy, post-refractive surgery, and others. In this review, we have summarized the current literature on the association between these ocular surface diseases and the presentation of corneal microneuromas, as well as elaborated on their pathogenesis, visualization via in vivo confocal microscopy, and utility in monitoring treatment efficacy. As current quantitative analysis on neuromas mainly relies on manual annotation and quantification, which is user-dependent and labor-intensive, future direction includes the development of artificial intelligence software to identify and quantify these potential imaging biomarkers in a more automated and sensitive manner, allowing it to be applied in clinical settings more efficiently. Combining imaging and molecular biomarkers may also help elucidate the associations between corneal neuromas and ocular surface diseases.
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Affiliation(s)
| | - Chang Liu
- Singapore Eye Research Institute, Singapore
| | | | | | - Louis Tong
- Singapore Eye Research Institute, Singapore
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Yu-Chi Liu
- Singapore Eye Research Institute, Singapore
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
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9
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Sierra-Silvestre E, Andrade RJ, Colorado LH, Edwards K, Coppieters MW. Occurrence of corneal sub-epithelial microneuromas and axonal swelling in people with diabetes with and without (painful) diabetic neuropathy. Diabetologia 2023; 66:1719-1734. [PMID: 37301795 PMCID: PMC10257488 DOI: 10.1007/s00125-023-05945-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 04/04/2023] [Indexed: 06/12/2023]
Abstract
AIMS/HYPOTHESIS Non-invasive in vivo corneal confocal microscopy is gaining ground as an alternative to skin punch biopsy to evaluate small-diameter nerve fibre characteristics. This study aimed to further explore corneal nerve fibre pathology in diabetic neuropathy. METHODS This cross-sectional study quantified and compared corneal nerve morphology and microneuromas in participants without diabetes (n=27), participants with diabetes but without distal symmetrical polyneuropathy (DSPN; n=33), participants with non-painful DSPN (n=25) and participants with painful DSPN (n=18). Clinical and electrodiagnostic criteria were used to diagnose DSPN. ANCOVA was used to compare nerve fibre morphology in the central cornea and inferior whorl, and the number of corneal sub-epithelial microneuromas between groups. Fisher's exact tests were used to compare the type and presence of corneal sub-epithelial microneuromas and axonal swelling between groups. RESULTS Various corneal nerve morphology metrics, such as corneal nerve fibre length and density, showed a progressive decline across the groups (p<0.001). In addition, axonal swelling was present more frequently (p=0.018) and in higher numbers (p=0.03) in participants with painful compared with non-painful DSPN. The frequency of axonal distension, a type of microneuroma, was increased in participants with painful and non-painful DSPN compared to participants with diabetes but without DSPN and participants without diabetes (all p≤0.042). The combined presence of all microneuromas and axonal swelling was increased in participants with painful DSPN compared with all other groups (p≤0.026). CONCLUSIONS/INTERPRETATION Microneuromas and axonal swelling in the cornea increase in prevalence from participants with diabetes to participants with non-painful DSPN and participants with painful DSPN.
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Affiliation(s)
- Eva Sierra-Silvestre
- Menzies Health Institute Queensland, Griffith University, Brisbane, QLD, Australia
- School of Health Sciences and Social Work, Griffith University, Brisbane, QLD, Australia
- Amsterdam Movement Sciences - Musculoskeletal Health Program, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Ricardo J Andrade
- Menzies Health Institute Queensland, Griffith University, Brisbane, QLD, Australia
- Movement - Interactions - Performance (MIP), Nantes University, Nantes, France
| | - Luisa H Colorado
- Centre for Vision and Eye Research, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Katie Edwards
- Centre for Vision and Eye Research, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Michel W Coppieters
- Menzies Health Institute Queensland, Griffith University, Brisbane, QLD, Australia.
- School of Health Sciences and Social Work, Griffith University, Brisbane, QLD, Australia.
- Amsterdam Movement Sciences - Musculoskeletal Health Program, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
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10
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Wu M, Chinnery HR, De Silva MEH, Downie LE. Characterisation and clustering of corneal stromal-epithelial nerve penetration sites in healthy adults: A laser-scanning in vivo confocal microscopy study. Clin Exp Ophthalmol 2023; 51:746-749. [PMID: 37463834 DOI: 10.1111/ceo.14276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 07/02/2023] [Indexed: 07/20/2023]
Affiliation(s)
- Mengliang Wu
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Manikkuwadura E H De Silva
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
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11
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Gomes JAP, Azar DT, Baudouin C, Bitton E, Chen W, Hafezi F, Hamrah P, Hogg RE, Horwath-Winter J, Kontadakis GA, Mehta JS, Messmer EM, Perez VL, Zadok D, Willcox MDP. TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface. Ocul Surf 2023; 29:331-385. [PMID: 37087043 DOI: 10.1016/j.jtos.2023.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 04/24/2023]
Abstract
The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.
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Affiliation(s)
- José Alvaro P Gomes
- Dept. of Ophthalmology and Visual Sciences, Federal University of Sao Paulo/Paulista School of Medicine (UNIFESP/EPM), Sao Paulo, SP, Brazil.
| | - Dimitri T Azar
- University of Illinois College of Medicine, Chicago, IL, USA
| | - Christophe Baudouin
- Quinze-Vingts National Eye Hospital & Vision Institute, IHU FOReSIGHT, Paris, France
| | - Etty Bitton
- Ecole d'optométrie, Université de Montréal, Montréal, Canada
| | - Wei Chen
- Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | | | - Pedram Hamrah
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Ruth E Hogg
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Belfast, UK
| | | | | | | | | | - Victor L Perez
- Foster Center for Ocular Immunology, Duke University Eye Center, Durham, NC, USA
| | - David Zadok
- Shaare Zedek Medical Center, Affiliated to the Hebrew University, School of Medicine, Jerusalem, Israel
| | - Mark D P Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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12
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Chiang JCB, Roy M, Kim J, Markoulli M, Krishnan AV. In-vivo corneal confocal microscopy: Imaging analysis, biological insights and future directions. Commun Biol 2023; 6:652. [PMID: 37336941 DOI: 10.1038/s42003-023-05005-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/31/2023] [Indexed: 06/21/2023] Open
Abstract
In-vivo corneal confocal microscopy is a powerful imaging technique which provides clinicians and researcher with the capabilities to observe microstructures at the ocular surfaces in significant detail. In this Mini Review, the optics and image analysis methods with the use of corneal confocal microscopy are discussed. While novel insights of neuroanatomy and biology of the eyes, particularly the ocular surface, have been provided by corneal confocal microscopy, some debatable elements observed using this technique remain and these are explored in this Mini Review. Potential improvements in imaging methodology and instrumentation are also suggested.
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Affiliation(s)
- Jeremy Chung Bo Chiang
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, NSW, UK
| | - Maitreyee Roy
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Juno Kim
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Maria Markoulli
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Arun V Krishnan
- School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia.
- Department of Neurology, Prince of Wales Hospital, Sydney, NSW, Australia.
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Wareham LK, Holden JM, Bossardet OL, Baratta RO, Del Buono BJ, Schlumpf E, Calkins DJ. Collagen mimetic peptide repair of the corneal nerve bed in a mouse model of dry eye disease. Front Neurosci 2023; 17:1148950. [PMID: 37260844 PMCID: PMC10228686 DOI: 10.3389/fnins.2023.1148950] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 04/21/2023] [Indexed: 06/02/2023] Open
Abstract
The intraepithelial sub-basal nerve plexus of the cornea is characterized by a central swirl of nerve processes that terminate between the apical cells of the epithelium. This plexus is a critical component of maintaining homeostatic function of the ocular surface. The cornea contains a high concentration of collagen, which is susceptible to damage in conditions such as neuropathic pain, neurotrophic keratitis, and dry eye disease. Here we tested whether topical application of a collagen mimetic peptide (CMP) is efficacious in repairing the corneal sub-basal nerve plexus in a mouse model of ocular surface desiccation. We induced corneal tear film reduction, epithelial damage, and nerve bed degradation through a combination of environmental and pharmaceutical (atropine) desiccation. Mice were subjected to desiccating air flow and bilateral topical application of 1% atropine solution (4× daily) for 2 weeks. During the latter half of this exposure, mice received topical vehicle [phosphate buffered saline (PBS)] or CMP [200 μm (Pro-Pro-Gly)7, 10 μl] once daily, 2 h prior to the first atropine treatment for that day. After euthanasia, cornea were labeled with antibodies against βIII tubulin to visualize and quantify changes to the nerve bed. For mice receiving vehicle only, the two-week desiccation regimen reduced neuronal coverage of the central sub-basal plexus and epithelial terminals compared to naïve, with some corneas demonstrating complete degeneration of nerve beds. Accordingly, both sub-basal and epithelial βIII tubulin-labeled processes demonstrated increased fragmentation, indicative of nerve disassembly. Treatment with CMP significantly reduced nerve fragmentation, expanded both sub-basal and epithelial neuronal coverage compared to vehicle controls, and improved corneal epithelium integrity, tear film production, and corneal sensitivity. Together, these results indicate that topical CMP significantly counters neurodegeneration characteristic of corneal surface desiccation. Repairing underlying collagen in conditions that damage the ocular surface could represent a novel therapeutic avenue in treating a broad spectrum of diseases or injury.
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Affiliation(s)
- Lauren K. Wareham
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Joseph M. Holden
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Olivia L. Bossardet
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | | | | | - Eric Schlumpf
- Stuart Therapeutics, Inc., Stuart, FL, United States
| | - David J. Calkins
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
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Sprogyte L, Park M, Di Girolamo N. Pathogenesis of Alkali Injury-Induced Limbal Stem Cell Deficiency: A Literature Survey of Animal Models. Cells 2023; 12:cells12091294. [PMID: 37174694 PMCID: PMC10177508 DOI: 10.3390/cells12091294] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/28/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
Limbal stem cell deficiency (LSCD) is a debilitating ocular surface disease that eventuates from a depleted or dysfunctional limbal epithelial stem cell (LESC) pool, resulting in corneal epithelial failure and blindness. The leading cause of LSCD is a chemical burn, with alkali substances being the most common inciting agents. Characteristic features of alkali-induced LSCD include corneal conjunctivalization, inflammation, neovascularization and fibrosis. Over the past decades, animal models of corneal alkali burn and alkali-induced LSCD have been instrumental in improving our understanding of the pathophysiological mechanisms responsible for disease development. Through these paradigms, important insights have been gained with regards to signaling pathways that drive inflammation, neovascularization and fibrosis, including NF-κB, ERK, p38 MAPK, JNK, STAT3, PI3K/AKT, mTOR and WNT/β-catenin cascades. Nonetheless, the molecular and cellular events that underpin re-epithelialization and those that govern long-term epithelial behavior are poorly understood. This review provides an overview of the current mechanistic insights into the pathophysiology of alkali-induced LSCD. Moreover, we highlight limitations regarding existing animal models and knowledge gaps which, if addressed, would facilitate development of more efficacious therapeutic strategies for patients with alkali-induced LSCD.
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Affiliation(s)
- Lina Sprogyte
- Mechanisms of Disease and Translational Research, School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
| | - Mijeong Park
- Mechanisms of Disease and Translational Research, School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nick Di Girolamo
- Mechanisms of Disease and Translational Research, School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
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15
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Recovery of Corneal Innervation after Treatment in Dry Eye Disease: A Confocal Microscopy Study. J Clin Med 2023; 12:jcm12051841. [PMID: 36902628 PMCID: PMC10003258 DOI: 10.3390/jcm12051841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/23/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
PURPOSE To analyze the changes in corneal innervation by means of in vivo corneal confocal microscopy (IVCM) in patients diagnosed with Evaporative (EDE) and Aqueous Deficient Dry Eye (ADDE) and treated with a standard treatment for Dry Eye Disease (DED) in combination with Plasma Rich in Growth Factors (PRGF). METHODS Eighty-three patients diagnosed with DED were enrolled in this study and included in the EDE or ADDE subtype. The primary variables analyzed were the length, density and number of nerve branches, and the secondary variables were those related to the quantity and stability of the tear film and the subjective response of the patients measured with psychometric questionnaires. RESULTS The combined treatment therapy with PRGF outperforms the standard treatment therapy in terms of subbasal nerve plexus regeneration, significantly increasing length, number of branches and nerve density, as well as significantly improving the stability of the tear film (p < 0.05 for all of them), and the most significant changes were located in the ADDE subtype. CONCLUSIONS the corneal reinnervation process responds in a different way depending on the treatment prescribed and the subtype of dry eye disease. In vivo confocal microscopy is presented as a powerful technique in the diagnosis and management of neurosensory abnormalities in DED.
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Wu M, Downie LE, Hill LJ, Chinnery HR. Topical Decorin Reduces Corneal Inflammation and Imparts Neuroprotection in a Mouse Model of Benzalkonium Chloride-induced Corneal Neuropathy. Invest Ophthalmol Vis Sci 2023; 64:20. [PMID: 36809303 PMCID: PMC9946044 DOI: 10.1167/iovs.64.2.20] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Purpose We evaluated the neuroprotective and immunomodulatory effects of topical decorin in a murine model of benzalkonium chloride (BAK)-induced corneal neuropathy. Methods Topical BAK (0.1%) was administered daily to both eyes of female C57BL/6J mice (n = 14) for 7 days. One group of mice received topical decorin (1.07 mg/mL) eye drops to one eye and saline (0.9%) to the contralateral eye; the other group received saline eye drops to both eyes. All eye drops were given three times daily over the experimental period. A control group (n = 8) received daily topical saline only, instead of BAK. Optical coherence tomography imaging was performed before (at day 0) and after (day 7) treatment to evaluate the central corneal thickness. Whole-mount immunofluorescence staining was performed to evaluate the density of corneal intraepithelial nerves and immune cells. Results BAK-exposed eyes showed corneal epithelial thinning, infiltration of inflammatory macrophages and neutrophils, and a lower density of intraepithelial nerves. No change to the corneal stromal thickness or dendritic cell density was observed. After BAK exposure, decorin-treated eyes had a lower density of macrophages and less neutrophil infiltration and a higher nerve density than the saline-treated group. Contralateral eyes from the decorin-treated animals showed fewer macrophages and neutrophils relative to saline-treated animals. A negative correlation was found between corneal nerve density and macrophage or neutrophil density. Conclusions Topical decorin provides neuroprotective and anti-inflammatory effects in a chemical model of BAK-induced corneal neuropathy. The attenuation of corneal inflammation by decorin may contribute to decreasing corneal nerve degeneration induced by BAK.
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Affiliation(s)
- Mengliang Wu
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Laura E. Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Lisa J. Hill
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Holly R. Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
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17
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Di Girolamo N, Park M. Cell identity changes in ocular surface Epithelia. Prog Retin Eye Res 2022:101148. [DOI: 10.1016/j.preteyeres.2022.101148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/13/2022] [Accepted: 11/09/2022] [Indexed: 11/21/2022]
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18
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Neuroimmune crosstalk in the cornea: The role of immune cells in corneal nerve maintenance during homeostasis and inflammation. Prog Retin Eye Res 2022; 91:101105. [PMID: 35868985 DOI: 10.1016/j.preteyeres.2022.101105] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 12/29/2022]
Abstract
In the cornea, resident immune cells are in close proximity to sensory nerves, consistent with their important roles in the maintenance of nerves in both homeostasis and inflammation. Using in vivo confocal microscopy in humans, and ex vivo immunostaining and fluorescent reporter mice to visualize corneal sensory nerves and immune cells, remarkable progress has been made to advance our understanding of the physical and functional interactions between corneal nerves and immune cells. In this review, we summarize and discuss recent studies relating to corneal immune cells and sensory nerves, and their interactions in health and disease. In particular, we consider how disrupted corneal nerve axons can induce immune cell activity, including in dendritic cells, macrophages and other infiltrating cells, directly and/or indirectly by releasing neuropeptides such as substance P and calcitonin gene-related peptide. We summarize growing evidence that the role of corneal intraepithelial immune cells is likely different in corneal wound healing versus other inflammatory-dominated conditions. The role of different types of macrophages is also discussed, including how stromal macrophages with anti-inflammatory phenotypes communicate with corneal nerves to provide neuroprotection, while macrophages with pro-inflammatory phenotypes, along with other infiltrating cells including neutrophils and CD4+ T cells, can be inhibitory to corneal re-innervation. Finally, this review considers the bidirectional interactions between corneal immune cells and corneal nerves, and how leveraging this interaction could represent a potential therapeutic approach for corneal neuropathy.
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19
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Corneal nerves and their role in dry eye pathophysiology. Exp Eye Res 2022; 222:109191. [PMID: 35850173 DOI: 10.1016/j.exer.2022.109191] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/15/2022] [Accepted: 07/11/2022] [Indexed: 12/11/2022]
Abstract
As the cornea is densely innervated, its nerves are integral not only to its structure but also to its pathophysiology. Corneal integrity depends on a protective tear film that is maintained by corneal sensation and the reflex arcs that control tearing and blinking. Furthermore, corneal nerves promote epithelial growth and local immunoregulation. Thus, corneal nerves constitute pillars of ocular surface homeostasis. Conversely, the abnormal tear film in dry eye favors corneal epithelial and nerve damage. The ensuing corneal nerve dysfunction contributes to dry eye progression, ocular pain and discomfort, and other neuropathic symptoms. Recent evidence from clinical studies and animal models highlight the significant but often overlooked neural dimension of dry eye pathophysiology. Herein, we review the anatomy and physiology of corneal nerves before exploring their role in the mechanisms of dry eye disease.
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20
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Chinnery HR, Rajan R, Jiao H, Wu M, Zhang AC, De Silva MEH, Makrai E, Stepp MA, Di Girolamo N, Downie LE. Identification of presumed corneal neuromas and microneuromas using laser-scanning in vivo confocal microscopy: a systematic review. Br J Ophthalmol 2022; 106:765-771. [PMID: 33568390 PMCID: PMC8353004 DOI: 10.1136/bjophthalmol-2020-318156] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/28/2020] [Accepted: 01/19/2021] [Indexed: 11/03/2022]
Abstract
BACKGROUND/AIMS This systematic review critically evaluated peer-reviewed publications describing morphological features consistent with, or using terms related to, a 'neuroma' or 'microneuroma' in the human cornea using laser-scanning in vivo confocal microscopy (IVCM). METHODS The review was prospectively registered on PROSPERO (CRD42020160038). Comprehensive literature searches were performed in Ovid MEDLINE, Ovid Embase and the Cochrane Library in November 2019. The review included primary research studies and reviews that described laser-scanning IVCM for examining human corneal nerves. Papers had to include at least one of a pre-specified set of keyword stems, broadly related to neuromas and microneuromas, to describe a corneal nerve feature. RESULTS Twenty-five papers (20 original studies; 5 reviews) were eligible. Three original studies evaluated corneal nerve features in healthy eyes. Most papers assessed corneal nerves in ocular and systemic conditions; seven studies did not include a control/comparator group. There was overlap in terminology used to describe nerve features in healthy and diseased corneas (eg, bulb-like/bulbous, penetration, end/s/ing). Inspection of IVCM images within the papers revealed that features termed 'neuromas' and 'microneuromas' could potentially be physiological corneal stromal-epithelial nerve penetration sites. We identified inconsistent definitions for terms, and limitations in IVCM image acquisition, sampling and/or reporting that may introduce bias and lead to inaccurate representation of physiological nerve characteristics as pathological. CONCLUSION These findings identify a need for consistent nomenclature and definitions, and rigorous IVCM scanning and analysis protocols to clarify the prevalence of physiological, as opposed to pathological, corneal nerve features.
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Affiliation(s)
- Holly Rose Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Rajni Rajan
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Haihan Jiao
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Mengliang Wu
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Alexis Ceecee Zhang
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | | | - Eve Makrai
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Mary Ann Stepp
- School of Medicine & Health Sciences, The George Washington University, Washington, DC, USA
| | - Nick Di Girolamo
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Laura Elizabeth Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
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21
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Dong Q, Wu D, Li M, Dong W. Polysaccharides, as biological macromolecule-based scaffolding biomaterials in cornea tissue engineering: A review. Tissue Cell 2022; 76:101782. [PMID: 35339801 DOI: 10.1016/j.tice.2022.101782] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 12/13/2022]
Abstract
Corneal-related diseases and injuries are the leading causes of vision loss, estimated to affect over 10 million people worldwide. Currently, cadaveric corneal grafts are considered the gold standard of treatment to restore cornea-related vision. However, this treatment modality faces different challenges such as donor shortage and graft failure. Therefore, the need for alternative solutions continues to grow. Tissue engineering has dramatically progressed to produce artificial cornea implants in order to repair, regenerate, or replace the damaged cornea. In this regard, a variety of polysaccharides such as cellulose, chitosan, alginate, agarose, and hyaluronic acid have been widely explored as scaffolding biomaterials for the production of tissue-engineered cornea. These polymers are known for their excellent biocompatibility, versatile properties, and processability. Recent progress and future perspectives of polysaccharide-based biomaterials in cornea tissue engineering is reviewed here.
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Affiliation(s)
- Qiwei Dong
- School of medicine, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan, China
| | - Dingkun Wu
- Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology, Dalian, Liaoning, China, 116024
| | - Moqiu Li
- Center for Cancer Prevention Research, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610041, China
| | - Wei Dong
- School of Mathematics Sciences, Shanxi University, Taiyuan 030006, China.
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22
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Dermer H, Hwang J, Mittal R, Cohen AK, Galor A. Corneal sub-basal nerve plexus microneuromas in individuals with and without dry eye. Br J Ophthalmol 2022; 106:616-622. [PMID: 33397656 PMCID: PMC8254821 DOI: 10.1136/bjophthalmol-2020-317891] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/12/2020] [Accepted: 12/12/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND/AIM An objective marker is needed to detect when corneal nerve abnormalities underlie neuropathic corneal pain (NCP), as symptoms often overlap with those of dry eye (DE). This study evaluated microneuroma (MN) frequency in various populations and investigated relationships between MN presence and DE clinical features in individuals with DE symptoms but without a history of refractive surgery, in order to eliminate refractive surgery as a potential confounder of nerve abnormalities. METHODS This was a retrospective study that included individuals with and without DE symptoms who underwent a clinical evaluation for DE (symptom surveys and ocular surface evaluation) and in vivo confocal microscopy imaging. DE clinical features (including those suggestive of neuropathic pain) were compared based on MN presence using t-tests, χ2 analyses and Pearson's correlation coefficients with 0.05 alpha level. RESULTS MN frequencies did not significantly differ between individuals with DE symptoms (Dry Eye Questionnaire 5 score ≥6) and a history of refractive surgery (n=1/16, 6%), individuals with DE symptoms without a history of refractive surgery (n=26/119, 22%) and individuals without DE symptoms (n=2/18, 11%, p=0.22). Among individuals with DE symptoms without a history of refractive surgery, DE clinical features, including those indicative of NCP (burning sensation and sensitivity to light, wind and extreme temperatures), did not significantly differ based on MN presence (p>0.05). CONCLUSION MN frequencies did not significantly differ between individuals with and without DE symptoms. Their presence alone could not distinguish between DE subtypes, including features of NCP in our study population.
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Affiliation(s)
- Harrison Dermer
- Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Jodi Hwang
- Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Rhiya Mittal
- Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Adam K Cohen
- Ophthalmology, Bruce W Carter Department of Veterans Affairs Medical Center, Miami, Florida, USA
| | - Anat Galor
- Ophthalmology, Bruce W Carter Department of Veterans Affairs Medical Center, Miami, Florida, USA
- Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, USA
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23
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ŞİMŞEK C. Sjögren sendromuna bağlı gelişen kuru göz hastalığında meydana gelen oküler yüzey değişikliklerinin konfokal mikroskopi ile değerlendirilmesi. EGE TIP DERGISI 2022. [DOI: 10.19161/etd.1086117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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How Should Corneal Nerves be Incorporated Into the Diagnosis and Management of Dry Eye? CURRENT OPHTHALMOLOGY REPORTS 2022; 9:65-76. [PMID: 35036080 DOI: 10.1007/s40135-021-00268-y] [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: 10/21/2022]
Abstract
Purpose a)Confocal microscopy and aethesiometry have allowed clinicians to assess the structural and functional integrity of corneal nerves in health and disease. This review summarizes literature on nerves in dry eye disease (DED) and discusses how this data can be applied to DED diagnosis and treatment. Recent findings b)Subjects with DED have a heterogenous symptom and sign profile along with variability in nerve structure and function. Most studies have reported lower nerve density and sensitivity in aqueous tear deficiency, while findings are more inconsistent for other DED subtypes. Examining nerve status, along with profiling symptoms and signs of disease, can help categorize subjects into disease phenotypes (structural and functional patterns) that exist under the umbrella of DED. This, in turn, can guide therapeutic decision-making. Summary c)Due to the heterogeneity in symptoms and signs of DED, corneal nerve evaluations can be valuable for categorizing individuals into disease sub-types and for guiding clinical decision making.
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25
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Barros A, Queiruga-Piñeiro J, Lozano-Sanroma J, Alcalde I, Gallar J, Fernández-Vega Cueto L, Alfonso JF, Quirós LM, Merayo-Lloves J. Small fiber neuropathy in the cornea of Covid-19 patients associated with the generation of ocular surface disease. Ocul Surf 2021; 23:40-48. [PMID: 34781021 PMCID: PMC8588585 DOI: 10.1016/j.jtos.2021.10.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 10/18/2021] [Accepted: 10/29/2021] [Indexed: 12/17/2022]
Abstract
Purpose To describe the association between Sars-CoV-2 infection and small fiber neuropathy in the cornea identified by in vivo corneal confocal microscopy. Methods Twenty-three patients who had overcome COVID-19 were recruited to this observational retrospective study. Forty-six uninfected volunteers were also recruited and studied as a control group. All subjects were examined under in vivo confocal microscopy to obtain images of corneal subbasal nerve fibers in order to study the presence of neuroma-like structures, axonal beadings and dendritic cells. The Ocular Surface Disease Index (OSDI) questionnaire and Schirmer tear test were used as indicators of Dry Eye Disease (DED) and ocular surface pathology. Results Twenty-one patients (91.31%) presented alterations of the corneal subbasal plexus and corneal tissue consistent with small fiber neuropathy. Images from healthy subjects did not indicate significant nerve fiber or corneal tissue damage. Eight patients reported increased sensations of ocular dryness after COVID-19 infection and had positive DED indicators. Beaded axons were found in 82.60% of cases, mainly in patients reporting ocular irritation symptoms. Neuroma-like images were found in 65.22% patients, more frequently in those with OSDI scores >13. Dendritic cells were found in 69.56% of patients and were more frequent in younger asymptomatic patients. The presence of morphological alterations in patients up to 10 months after recovering from Sars-CoV-2 infection points to the chronic nature of the neuropathy. Conclusions Sars-CoV-2 infection may be inducing small fiber neuropathy in the ocular surface, sharing symptomatology and morphological landmarks with DED and diabetic neuropathy.
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Affiliation(s)
| | | | | | - Ignacio Alcalde
- Instituto Universitario Fernández-Vega, Universidad de Oviedo & Fundación de Investigación Oftalmológica, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain.
| | - Juana Gallar
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, San Juan de Alicante, Spain
| | - Luis Fernández-Vega Cueto
- Instituto Oftalmológico Fernández-Vega, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain.
| | - José F Alfonso
- Instituto Oftalmológico Fernández-Vega, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; Department of Surgery and Medical-Surgical Specialties, Universidad de Oviedo, Oviedo, Spain
| | - Luis M Quirós
- Instituto Universitario Fernández-Vega, Universidad de Oviedo & Fundación de Investigación Oftalmológica, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; Department of Functional Biology, Universidad de Oviedo, Oviedo, Spain
| | - Jesús Merayo-Lloves
- Instituto Oftalmológico Fernández-Vega, Oviedo, Spain; Instituto Universitario Fernández-Vega, Universidad de Oviedo & Fundación de Investigación Oftalmológica, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; Department of Surgery and Medical-Surgical Specialties, Universidad de Oviedo, Oviedo, Spain
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26
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Guerrero-Moreno A, Liang H, Moreau N, Luzu J, Rabut G, Melik Parsadaniantz S, Labbé A, Baudouin C, Réaux-Le Goazigo A. Corneal Nerve Abnormalities in Painful Dry Eye Disease Patients. Biomedicines 2021; 9:biomedicines9101424. [PMID: 34680542 PMCID: PMC8533181 DOI: 10.3390/biomedicines9101424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/28/2021] [Accepted: 10/07/2021] [Indexed: 12/24/2022] Open
Abstract
Background: This study aimed to compare the corneal nerve structural abnormalities detected using in vivo confocal microscopy (IVCM) in patients with neuropathic corneal pain (NCP) secondary to primary meibomian gland dysfunction (MGD) or autoimmune dry eye (AIDE). Methods: A two-stage retrospective nested case-control study was conducted. First, data from patients with either MGD or AIDE were assessed, selecting only cases with no corneal pain (VAS = 0) or severe pain (VAS ≥ 8). Ocular signs and symptoms of the 238 selected patients were compared between painful and painless cases. Next, painful patients with no corneal damage (Oxford score ≤ 1) were selected within each study group, defining the cases with NCP (i.e., "pain without stain"). IVCM images from all groups were compared with prospectively-recruited healthy controls, focusing on dendritiform cell density and nerve abnormalities (density, tortuosity, microneuromas). Results: AIDE patients had more ocular signs/symptoms than MGD patients. Compared with healthy controls, AIDE-related NCP patients showed increased nerve tortuosity and number of neuromas, whereas MGD-related NCP patients had reduced nerve density and increased number, perimeter, and area of microneuromas. Microneuromas were also observed in healthy controls. Furthermore, a higher number of microneuromas was found in MGD-related NCP compared to AIDE-related NCP or painless MGD. Conclusions: MGD-related NCP was associated with significantly more corneal nerve abnormalities than AIDE-related NCP or healthy controls. Although IVCM can be useful to detect NCP-related corneal nerve changes in such patients, the diagnosis of dry eye disease-related NCP will require an association of several IVCM-based criteria without relying solely on the presence of microneuromas.
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Affiliation(s)
- Adrian Guerrero-Moreno
- Institut de la Vision, INSERM, CNRS, Sorbonne Université, 17 rue Moreau, 75012 Paris, France; (A.G.-M.); (H.L.); (N.M.); (S.M.P.); (C.B.)
| | - Hong Liang
- Institut de la Vision, INSERM, CNRS, Sorbonne Université, 17 rue Moreau, 75012 Paris, France; (A.G.-M.); (H.L.); (N.M.); (S.M.P.); (C.B.)
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 17 rue Moreau, 75012 Paris, France; (J.L.); (G.R.); (A.L.)
| | - Nathan Moreau
- Institut de la Vision, INSERM, CNRS, Sorbonne Université, 17 rue Moreau, 75012 Paris, France; (A.G.-M.); (H.L.); (N.M.); (S.M.P.); (C.B.)
| | - Jade Luzu
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 17 rue Moreau, 75012 Paris, France; (J.L.); (G.R.); (A.L.)
| | - Ghislaine Rabut
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 17 rue Moreau, 75012 Paris, France; (J.L.); (G.R.); (A.L.)
| | - Stéphane Melik Parsadaniantz
- Institut de la Vision, INSERM, CNRS, Sorbonne Université, 17 rue Moreau, 75012 Paris, France; (A.G.-M.); (H.L.); (N.M.); (S.M.P.); (C.B.)
| | - Antoine Labbé
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 17 rue Moreau, 75012 Paris, France; (J.L.); (G.R.); (A.L.)
- Department of Ophthalmology, Ambroise Paré Hospital, AP-HP, University of Versailles Saint-Quentin-en-Yvelines, 9 Avenue Charles de Gaulle, 92100 Boulogne-Billancourt, France
| | - Christophe Baudouin
- Institut de la Vision, INSERM, CNRS, Sorbonne Université, 17 rue Moreau, 75012 Paris, France; (A.G.-M.); (H.L.); (N.M.); (S.M.P.); (C.B.)
- CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 17 rue Moreau, 75012 Paris, France; (J.L.); (G.R.); (A.L.)
- Department of Ophthalmology, Ambroise Paré Hospital, AP-HP, University of Versailles Saint-Quentin-en-Yvelines, 9 Avenue Charles de Gaulle, 92100 Boulogne-Billancourt, France
| | - Annabelle Réaux-Le Goazigo
- Institut de la Vision, INSERM, CNRS, Sorbonne Université, 17 rue Moreau, 75012 Paris, France; (A.G.-M.); (H.L.); (N.M.); (S.M.P.); (C.B.)
- Correspondence: ; Tel.: +33-153462572
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Badian RA, Andréasson M, Svenningsson P, Utheim TP, Lagali N. The pattern of the inferocentral whorl region of the corneal subbasal nerve plexus is altered with age. Ocul Surf 2021; 22:204-212. [PMID: 34450219 DOI: 10.1016/j.jtos.2021.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 08/16/2021] [Accepted: 08/21/2021] [Indexed: 12/27/2022]
Abstract
PURPOSE To describe the pattern of the nerves in the inferocentral whorl region of the human corneal subbasal nerve plexus (SBNP) in health and diseases known to affect the subbasal nerves. METHODS Laser-scanning in vivo confocal microscopy (IVCM) was used to image the SBNP bilaterally in 91 healthy subjects, 39 subjects with type 2 diabetes mellitus (T2DM), and 43 subjects with Parkinson's disease (PD). Whorl regions were classified according to nerve orientation relative to age and health/disease status. RESULTS Of 346 examined eyes, 300 (86.7%) had an identifiable whorl pattern. In healthy subjects, a clockwise nerve orientation of the whorl was most common (67.9%), followed by non-rotatory or 'seam' morphology (21.4%), and counterclockwise (10.7%). The clockwise orientation was more prevalent in healthy subjects than in T2DM or PD (P < 0.001). Healthy individuals below 50 years of age had a predominantly clockwise orientation (93.8%) which was reduced to 51.9% in those over 50 years (P < 0.001). Age but not disease status explained whorl orientation in T2DM and PD groups. Moreover, whorl orientation is bilaterally clockwise in the young, but adopts other orientations and becomes asymmetric across eyes with age. Finally, we report reflective 'dot-like' features confined to the whorl region of the subbasal plexus, sometimes appearing in close association with subbasal nerves and present in 84-93% of examined eyes regardless of disease status, eye or sex. CONCLUSION Subbasal nerves in the inferocentral whorl region are predominantly clockwise in young, healthy corneas. With aging and conditions of T2DM and PD, counterclockwise and non-rotatory configurations increase in prevalence, and bilateral symmetry is lost. Mechanisms regulating these changes warrant further investigation.
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Affiliation(s)
- Reza A Badian
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.
| | - Mattias Andréasson
- Center for Neurology, Academic Specialist Center, Stockholm, Sweden; Department of Neurology, Karolinska University Hospital, Stockholm, Sweden; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Per Svenningsson
- Center for Neurology, Academic Specialist Center, Stockholm, Sweden; Department of Neurology, Karolinska University Hospital, Stockholm, Sweden; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tor Paaske Utheim
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway
| | - Neil Lagali
- Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway; Department of Ophthalmology, Institute for Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
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Chinnery HR, Zhang XY, Wu CY, Downie LE. Corneal immune cell morphometry as an indicator of local and systemic pathology: A review. Clin Exp Ophthalmol 2021; 49:729-740. [PMID: 34240800 DOI: 10.1111/ceo.13972] [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: 06/30/2021] [Accepted: 07/03/2021] [Indexed: 11/26/2022]
Abstract
The corneal epithelium contains a population of resident immune cells commonly referred to as dendritic cells (DCs), or Langerhans cells. A unique advantage of the transparent cornea being situated at the surface of the eye is that these cells can be readily visualised using in vivo confocal microscopy. Over the past decade, interest in the involvement of corneal DCs in a range of ocular and systemic diseases has surged. For most studies, the number of corneal DCs has been the main outcome of interest. However, more recently attention has shifted towards understanding how DC morphology may provide insights into the inflammatory status of the cornea, and in some cases, the health of the peripheral nervous system. In this review, we provide examples of recent methodologies that have been used to classify and measure corneal DC morphology and discuss how this relates to local and systemic inflammatory conditions in humans and rodents.
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Affiliation(s)
- Holly R Chinnery
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Xin Yuan Zhang
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Ching Yi Wu
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
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29
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Chiang JCB, Goldstein D, Park SB, Krishnan AV, Markoulli M. Corneal nerve changes following treatment with neurotoxic anticancer drugs. Ocul Surf 2021; 21:221-237. [PMID: 34144206 DOI: 10.1016/j.jtos.2021.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/20/2021] [Accepted: 06/09/2021] [Indexed: 12/13/2022]
Abstract
Survival rates of cancer has improved with the development of anticancer drugs including systemic chemotherapeutic agents. However, long-lasting side effects could impact treated patients. Neurotoxic anticancer drugs are specific agents which cause chemotherapy-induced peripheral neuropathy (CIPN), a debilitating condition that severely deteriorates quality of life of cancer patients and survivors. The ocular surface is also prone to neurotoxicity but investigation into the effects of neurotoxic chemotherapy on the ocular surface has been more limited compared to other systemic etiologies such as diabetes. There is also no standardized protocol for CIPN diagnosis with an absence of a reliable, objective method of observing nerve damage structurally. As the cornea is the most densely innervated region of the body, researchers have started to focus on corneal neuropathic changes that are associated with neurotoxic chemotherapy treatment. In-vivo corneal confocal microscopy enables rapid and objective structural imaging of ocular surface microscopic structures such as corneal nerves, while esthesiometers provide means of functional assessment by examining corneal sensitivity. The current article explores the current guidelines and gaps in our knowledge of CIPN diagnosis and the potential role of in-vivo corneal confocal microscopy as a diagnostic or prognostic tool. Corneal neuropathic changes with neurotoxic anticancer drugs from animal research progressing through to human clinical studies are also discussed, with a focus on how these data inform our understanding of CIPN.
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Affiliation(s)
- Jeremy Chung Bo Chiang
- School of Optometry & Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, Australia.
| | - David Goldstein
- Prince of Wales Clinical School, University of New South Wales, Sydney, Australia; Department of Medical Oncology, Prince of Wales Hospital, Sydney, Australia
| | - Susanna B Park
- Brain and Mind Centre, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Arun V Krishnan
- Prince of Wales Clinical School, University of New South Wales, Sydney, Australia
| | - Maria Markoulli
- School of Optometry & Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, Australia
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30
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Pal-Ghosh S, Tadvalkar G, Karpinski BA, Stepp MA. Diurnal Control of Sensory Axon Growth and Shedding in the Mouse Cornea. Invest Ophthalmol Vis Sci 2021; 61:1. [PMID: 32870244 PMCID: PMC7476672 DOI: 10.1167/iovs.61.11.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose The circadian clock plays an important role in the expression and regulation of various genes and cellular processes in the body. Here, we study diurnal regulation of the growth and shedding of the sensory axons in the mouse cornea. Methods Male and female BALB/cN mice were euthanized 90 minutes before and after the lights are turned on and off; at 5:30 AM, 8:30 AM, 5:30 PM, and 8:30 PM. Nerve terminal growth, shedding and overall axon density were assessed at these four time points using confocal imaging after staining axons in en face whole mount corneas with antibodies against βIII tubulin, GAP43, and L1CAM. In addition, corneal epithelial cell proliferation, thickness, and desquamation were assessed using ki67, LAMP1, Involucrin, and ZO1. Results Nerve terminal shedding took place between 5:30 AM and 8:30 AM and correlated positively with the timing of apical cell desquamation. After shedding the tips of the nerve terminals, axonal growth increased as indicated by increased axonal GAP43 expression. At 5:30 PM and 8:30 PM before and after the lights are turned off, cell proliferation was reduced, and epithelial thickness was maximal. Conclusions Intraepithelial corneal nerve growth and shedding are under diurnal control regulated by the time of day and whether lights are on or off. Axons extend during the day and are shed within 90 minutes after lights are turned on. The data presented in this article shed light on the potential role that circadian clock plays in corneal pain and discomfort.
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Affiliation(s)
- Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
| | - Gauri Tadvalkar
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
| | - Beverly A Karpinski
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States.,Department of Ophthalmology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
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31
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Tuck H, Park M, Carnell M, Machet J, Richardson A, Jukic M, Di Girolamo N. Neuronal-epithelial cell alignment: A determinant of health and disease status of the cornea. Ocul Surf 2021; 21:257-270. [PMID: 33766739 DOI: 10.1016/j.jtos.2021.03.007] [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] [Received: 10/16/2020] [Revised: 02/22/2021] [Accepted: 03/16/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE How sensory neurons and epithelial cells interact with one another, and whether this association can be considered an indicator of health or disease is yet to be elucidated. METHODS Herein, we used the cornea, Confetti mice, a novel image segmentation algorithm for intraepithelial corneal nerves which was compared to and validated against several other analytical platforms, and three mouse models to delineate this paradigm. For aging, eyes were collected from 2 to 52 week-old normal C57BL/6 mice (n ≥ 4/time-point). For wound-healing and limbal stem cell deficiency, 7 week-old mice received a limbal-sparing or limbal-to-limbal epithelial debridement to their right cornea, respectively. Eyes were collected 2-16 weeks post-injury (n=4/group/time-point), corneas procured, immunolabelled with βIII-tubulin, flat-mounted, imaged by scanning confocal microscopy and analyzed for nerve and epithelial-specific parameters. RESULTS Our data indicate that nerve features are dynamic during aging and their curvilinear arrangement align with corneal epithelial migratory tracks. Moderate corneal injury prompted axonal regeneration and recovery of nerve fiber features. Limbal stem cell deficient corneas displayed abnormal nerve morphology, and fibers no longer aligned with corneal epithelial migratory tracks. Mechanistically, we discovered that nerve pattern restoration relies on the number and distribution of stromal-epithelial nerve penetration sites. CONCLUSIONS Microstructural changes to innervation may explain corneal complications related to aging and/or disease and facilitate development of new assays for diagnosis and/or classification of ocular and systemic diseases.
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Affiliation(s)
- Hugh Tuck
- School of Medical Sciences, Mechanisms of Disease and Translational Research, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Mijeong Park
- School of Medical Sciences, Mechanisms of Disease and Translational Research, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Michael Carnell
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Joshua Machet
- School of Medical Sciences, Mechanisms of Disease and Translational Research, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Alexander Richardson
- School of Medical Sciences, Mechanisms of Disease and Translational Research, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Marijan Jukic
- Melbourne School of Population and Global Health, Centre for Health Policy, University of Melbourne, Melbourne, Victoria, 3053, Australia
| | - Nick Di Girolamo
- School of Medical Sciences, Mechanisms of Disease and Translational Research, University of New South Wales, Sydney, New South Wales, 2052, Australia.
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32
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Hwang J, Dermer H, Galor A. Can in vivo confocal microscopy differentiate between sub-types of dry eye disease? A review. Clin Exp Ophthalmol 2021; 49:373-387. [PMID: 33769651 DOI: 10.1111/ceo.13924] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/16/2021] [Accepted: 03/20/2021] [Indexed: 12/25/2022]
Abstract
Many studies utilised in vivo confocal microscopy (IVCM) to associate variations in corneal structures with dry eye disease (DED). However, DED is an umbrella term that covers various aetiologies and presentations. This review analyses populations by DED aetiology to determine the relationships between IVCM parameters and specific DED sub-types. It focuses on the most commonly examined structures, sub-basal nerves and dendritic cells. Across the literature, most studies found individuals with immune-mediated DED had lower sub-basal nerve fibre number and density than controls, with smaller differences between non-immune DED and controls. However, wide ranges of values reported across studies demonstrate considerable overlap between DED sub-types and controls, rendering these metrics less helpful when diagnosing an individual patient. Dendritic cell density was considerably higher in individuals with immune-mediated DED than in non-immune DED or controls. As such, dendritic cell density may be a better indicator of DED associated with a systemic immune-mediated process.
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Affiliation(s)
- Jodi Hwang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami, Florida, USA.,Department of Ophthalmology, Miami Veterans Administration Medical Center, Miami, Florida, USA
| | - Harrison Dermer
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami, Florida, USA.,Department of Ophthalmology, Miami Veterans Administration Medical Center, Miami, Florida, USA
| | - Anat Galor
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami, Florida, USA.,Department of Ophthalmology, Miami Veterans Administration Medical Center, Miami, Florida, USA
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33
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Downie LE, Bandlitz S, Bergmanson JPG, Craig JP, Dutta D, Maldonado-Codina C, Ngo W, Siddireddy JS, Wolffsohn JS. CLEAR - Anatomy and physiology of the anterior eye. Cont Lens Anterior Eye 2021; 44:132-156. [PMID: 33775375 DOI: 10.1016/j.clae.2021.02.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 02/01/2021] [Indexed: 02/06/2023]
Abstract
A key element of contact lens practice involves clinical evaluation of anterior eye health, including the cornea and limbus, conjunctiva and sclera, eyelids and eyelashes, lacrimal system and tear film. This report reviews the fundamental anatomy and physiology of these structures, including the vascular supply, venous drainage, lymphatic drainage, sensory innervation, physiology and function. This is the foundation for considering the potential interactions with, and effects of, contact lens wear on the anterior eye. This information is not consistently published as academic research and this report provides a synthesis from all available sources. With respect to terminology, the report aims to promote the consistent use of nomenclature in the field, and generally adopts anatomical terms recommended by the Federative Committee for Anatomical Terminology. Techniques for the examination of the ocular surface are also discussed.
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Affiliation(s)
- Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Australia.
| | - Stefan Bandlitz
- Höhere Fachschule für Augenoptik Köln, Cologne School of Optometry, Germany; School of Optometry, Aston University, Birmingham, UK
| | - Jan P G Bergmanson
- Texas Eye Research and Technology Center, University of Houston College of Optometry, United States
| | - Jennifer P Craig
- Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, New Zealand
| | - Debarun Dutta
- School of Optometry, Aston University, Birmingham, UK
| | - Carole Maldonado-Codina
- Eurolens Research, Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - William Ngo
- Centre for Ocular Research & Education, School of Optometry & Vision Science, University of Waterloo, Waterloo, Canada; Centre for Eye and Vision Research (CEVR), 14W Hong Kong Science Park, Hong Kong
| | | | - James S Wolffsohn
- School of Optometry, Aston University, Birmingham, UK; Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, New Zealand
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34
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Baksh BS, Garcia JC, Galor A. Exploring the Link Between Dry Eye and Migraine: From Eye to Brain. Eye Brain 2021; 13:41-57. [PMID: 33692643 PMCID: PMC7939506 DOI: 10.2147/eb.s234073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/17/2021] [Indexed: 11/23/2022] Open
Abstract
Dry eye and migraine are common diseases with large societal and economic burdens that have recently been associated in the literature. This review outlines the link between dry eye and migraine, which may have implications for reducing their respective burdens. We highlight possible shared pathophysiology, including peripheral and central sensitization, as the potential link between dry eye and migraine. Finally, therapies targeting similar pathophysiological mechanisms between dry eye and migraine are discussed.
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Affiliation(s)
- Brandon S Baksh
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- University of Miami Miller School of Medicine, Miami, FL, USA
| | - Julia Costa Garcia
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Faculdade de Medicina (FMB) da Universidade do Estado de São Paulo (UNESP), Botucatu, Brazil
| | - Anat Galor
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Ophthalmology, Miami Veterans Affairs Medical Center, Miami, FL, USA
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35
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Stepp MA, Pal-Ghosh S, Tadvalkar G, de Paiva CS. Parity Attenuates Intraepithelial Corneal Sensory Nerve Loss in Female Mice. Int J Mol Sci 2020; 21:E5172. [PMID: 32708332 PMCID: PMC7404034 DOI: 10.3390/ijms21145172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/16/2020] [Accepted: 07/18/2020] [Indexed: 12/12/2022] Open
Abstract
Aging impacts the ocular surface and reduces intraepithelial corneal nerve (ICN) density in male and female mice. Many researchers use retired breeders to study naturally aged female mice. Yet, the impact of parity and the length of time since breeders were retired on age-related changes in the intraepithelial corneal nerves is not known. Here we study 2 month (M) nulliparous (NP) females as well as 9M, 10M, and 11M NP and multiparous (MP) female mice to determine whether parity impacts the age-related decline seen in corneal axon density; 9M male mice are also included in these assessments. After showing that parity attenuates age-related loss in axon density, we also assess the impact of parity on corneal epithelial cell proliferation and find that it impacts cell proliferation and axon density normalized by cell proliferation. Stromal nerve arborization is also impacted by aging with parity enhancing stromal nerves in older mice. qPCR was performed on 20 genes implicated in ICN density using corneal epithelial RNA isolated from 10M NP and MP mice and showed that NGF expression was significantly elevated in MP corneal epithelium. Corneal sensitivity was significantly higher in 9M MP mice compared to NP mice and increased sensitivity in MP mice was accompanied by increased nerve terminals in the apical and middle cell layers. Together, these data show that parity in mice attenuates several aspects of the age-related decline seen on the ocular surface by retaining sensory axons and corneal sensitivity as mice age.
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Affiliation(s)
- Mary Ann Stepp
- Department of Anatomy and Regenerative Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
- Department of Ophthalmology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Sonali Pal-Ghosh
- Department of Anatomy and Regenerative Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Gauri Tadvalkar
- Department of Anatomy and Regenerative Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Cintia S de Paiva
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA
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36
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Corneal In Vivo Laser-Scanning Confocal Microscopy Findings in Dry Eye Patients with Sjögren's Syndrome. Diagnostics (Basel) 2020; 10:diagnostics10070497. [PMID: 32698387 PMCID: PMC7400289 DOI: 10.3390/diagnostics10070497] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To evaluate the changes in cornea in Sjögren's syndrome (SS) with a novel confocal microscopy device. METHODS Twenty-three right eyes of patients with SS (23 women; mean age, 65.4 ± 11.4 years) and 13 right eyes of 13 age- and sex-matched control subjects (13 women; mean age, 68.8 ± 9.8 years) were studied. Furthermore, eight right eyes of patients with SS (8 women; mean age, 66.9 ± 9.6 years) were studied to evaluate the corneal microscopic alterations after the treatment with topical 3% diquafosol sodium eye drops. All cases had tear quantity, tear breakup time (BUT), ocular surface staining measurements, and corneal in vivo laser-scanning confocal microscopy examinations. The density and area of corneal epithelial cells (superficial, wing, and basal), density of corneal stromal cells (anterior, intermediate, and posterior), density and area of corneal endothelial cells, density and morphology of corneal sub-basal nerve plexus, density of corneal sub-basal inflammatory cells were also assessed. RESULTS The tear quantity, stability, and vital staining scores were significantly worse in patients with SS than in control subjects (p < 0.0001). Corneal superficial epithelial cell density was significantly lower in SS compared with control subjects (p < 0.0001). Corneal superficial epithelial cell area was significantly larger in SS compared with control subjects (p = 0.007). Corneal sub-basal nerve fiber density was lower in SS compared with control subjects (p < 0.0001). Morphological abnormality of nerve fibers was observed in SS patients. Corneal sub-basal inflammatory cell density was significantly higher in SS patients compared with control subjects (p < 0.0001). Furthermore, the mean corneal superficial epithelial cell density and area, inflammatory cell density, corneal sub-basal nerve fiber density, and morphological abnormality of nerve fibers, were improved with topical 3% diquafosol sodium treatment in the dry eye patients with SS (p < 0.05). CONCLUSIONS The diagnostic modality using in vivo laser-scanning confocal microscopy was a useful method for the evaluation of the corneal cell density and area, nerve fiber density and morphology, and inflammatory cell density in patients with SS and also a useful tool in the assessment of treatment effect with topical 3% diquafosol sodium in the SS patients.
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37
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Parlanti P, Pal-Ghosh S, Williams A, Tadvalkar G, Popratiloff A, Stepp MA. Axonal debris accumulates in corneal epithelial cells after intraepithelial corneal nerves are damaged: A focused Ion Beam Scanning Electron Microscopy (FIB-SEM) study. Exp Eye Res 2020; 194:107998. [PMID: 32209319 PMCID: PMC7697722 DOI: 10.1016/j.exer.2020.107998] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/13/2020] [Accepted: 03/07/2020] [Indexed: 12/15/2022]
Abstract
The intraepithelial corneal nerves (ICNs) that innervate the corneal epithelium are maintained through interactions with corneal epithelial cells and the extracellular matrix they produce. One to several axons bundle together within the basal cell layer and extend parallel to the ocular surface or branch and extend apically. Here we use 3-dimentional (3D) ultrastructural reconstructions of control and trephine injured mouse corneal epithelium and stroma produced using Focused Ion Beam Scanning Electron Microscope (FIB-SEM) to determine whether corneal epithelial or immune cells resident in the epithelium remove axonal debris and degrade it in their lysosomes after trephine injury to the cornea. We demonstrate that axonal fragments are internalized in the corneal epithelium and accumulate within electron dense structures consistent with lysosomes 3 h after trephine injury in both epithelial and immune cells located among the basal cells of the trephine injured cornea. Confocal imaging showed fewer CD45+ immune cells within the corneal epithelium after trephine injury compared to controls. The resolution obtained using FIB-SEM also allowed us to show that the presence of sensory axons at the basal aspect of the epithelial basal cells close to the anterior aspect of the epithelial basement membrane (EBM) is associated with a focal reduction in EBM thickness. In addition, we show using FIB-SEM and confocal imaging that superficial trephine injuries that do not penetrate the stroma, damage the integrity of anterior stromal nerves. These studies are the first to look at the mouse cornea following nerve injury using FIB-SEM.
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Affiliation(s)
- Paola Parlanti
- GW Nanofabrication and Imaging Center, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA
| | - Alexa Williams
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA
| | - Gauri Tadvalkar
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA
| | - Anastas Popratiloff
- GW Nanofabrication and Imaging Center, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA; Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA; Department of Ophthalmology, The George Washington School of Medicine and Health Sciences, Washington DC, 20052, USA.
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