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Badian RA, Lagali N. The inferocentral whorl region and its directional patterns in the corneal sub-basal nerve plexus: A review. Exp Eye Res 2024; 244:109926. [PMID: 38754688 DOI: 10.1016/j.exer.2024.109926] [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: 02/05/2024] [Revised: 04/03/2024] [Accepted: 05/12/2024] [Indexed: 05/18/2024]
Abstract
There has been a growing application of in vivo confocal microscopy (IVCM) in the examination of corneal microstructure, including different corneal layers and corneal nerve fibers in health and in pathological conditions. Corneal nerves forming the sub-basal nerve plexus (SBNP) beneath the corneal basal epithelial cell layer in particular have been intensively researched in health and disease as a marker for corneal neurophysioanatomical and degenerative changes. One intriguing feature in the SBNP that is found inferior to the corneal apex, is a whorl-like pattern (or vortex) of nerves, which represents an anatomical landmark. Evidence has indicated that the architecture of this 'whorl region' is dynamic, changing with time in healthy individuals but also in disease conditions such as in diabetic neuropathy and keratoconus. This review summarizes the known information regarding the characteristics and significance of the whorl region of nerves in the corneal SBNP, as a potential area of high relevance for future disease monitoring and diagnostics.
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Affiliation(s)
- Reza A Badian
- Department of Medical Biochemistry, Unit of Regenerative Medicine, Oslo University Hospital, Oslo, Norway.
| | - Neil Lagali
- Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway; Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, Linköping, Sweden.
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Chen M, Seo S, Simmons X, Maroud Y, Wong T, Schubert W, Yiu SC. Precise longitudinal monitoring of corneal change through in vivo confocal microscopy in a rat dry eye disease model. Mol Vis 2024; 30:150-159. [PMID: 39076769 PMCID: PMC11286106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 03/18/2024] [Indexed: 07/31/2024] Open
Abstract
Purpose While lacrimal gland removal is commonly used in animal models to replicate dry eye disease, research into systematically monitoring dry eye disease's longitudinal pathological changes is limited. In vivo confocal microscopy (Heidelberg Retina Tomograph 3 with a Rostock Cornea Module, Heidelberg Engineering Inc., Franklin, MA) can non-invasively reveal corneal histopathological structures. To monitor dry-eye-disease-related changes in corneal structures, we developed a precise monitoring method using in vivo confocal microscopy in a rat double lacrimal gland removal model. Methods Five Sprague-Dawley rats (age 8-9 weeks, male) underwent double lacrimal gland removal. Modified Schirmer's tear test, blink tests, and in vivo confocal microscopy images were acquired pre-surgery and at 1, 2, and 4 weeks post-surgery. Three individual stromal nerves were selected per eye as guide images, and images of the corresponding sub-basal nerve plexus area were acquired via volume acquisition. The same area was re-imaged in subsequent weeks. Results After double lacrimal gland removal, tear production was reduced by 60%, and the blink rate increased 10 times compared to pre-surgery. Starting from 1 week after surgery, in vivo confocal microscopy showed increased sub-basal nerve plexus nerve fiber density with inflammatory cell infiltration at the sub-basal nerve plexus layer and remained at an elevated level at 2 and 4 weeks post-surgery. Conclusions We demonstrated that our precise monitoring method revealed detailed changes in the corneal nerves, the epithelium, and the stroma.
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Affiliation(s)
- Minjie Chen
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Stefanie Seo
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Xianni Simmons
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Youssef Maroud
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Trystin Wong
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Samuel C Yiu
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
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3
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Kleinbeck S, Wolkoff P. Exposure limits for indoor volatile substances concerning the general population: The role of population-based differences in sensory irritation of the eyes and airways for assessment factors. Arch Toxicol 2024; 98:617-662. [PMID: 38243103 PMCID: PMC10861400 DOI: 10.1007/s00204-023-03642-w] [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: 09/22/2023] [Accepted: 11/16/2023] [Indexed: 01/21/2024]
Abstract
Assessment factors (AFs) are essential in the derivation of occupational exposure limits (OELs) and indoor air quality guidelines. The factors shall accommodate differences in sensitivity between subgroups, i.e., workers, healthy and sick people, and occupational exposure versus life-long exposure for the general population. Derivation of AFs itself is based on empirical knowledge from human and animal exposure studies with immanent uncertainty in the empirical evidence due to knowledge gaps and experimental reliability. Sensory irritation in the eyes and airways constitute about 30-40% of OELs and is an abundant symptom in non-industrial buildings characterizing the indoor air quality and general health. Intraspecies differences between subgroups of the general population should be quantified for the proposal of more 'empirical' based AFs. In this review, we focus on sensitivity differences in sensory irritation about gender, age, health status, and vulnerability in people, based solely on human exposure studies. Females are more sensitive to sensory irritation than males for few volatile substances. Older people appear less sensitive than younger ones. However, impaired defense mechanisms may increase vulnerability in the long term. Empirical evidence of sensory irritation in children is rare and limited to children down to the age of six years. Studies of the nervous system in children compared to adults suggest a higher sensitivity in children; however, some defense mechanisms are more efficient in children than in adults. Usually, exposure studies are performed with healthy subjects. Exposure studies with sick people are not representative due to the deselection of subjects with moderate or severe eye or airway diseases, which likely underestimates the sensitivity of the group of people with diseases. Psychological characterization like personality factors shows that concentrations of volatile substances far below their sensory irritation thresholds may influence the sensitivity, in part biased by odor perception. Thus, the protection of people with extreme personality traits is not feasible by an AF and other mitigation strategies are required. The available empirical evidence comprising age, lifestyle, and health supports an AF of not greater than up to 2 for sensory irritation. Further, general AFs are discouraged for derivation, rather substance-specific derivation of AFs is recommended based on the risk assessment of empirical data, deposition in the airways depending on the substance's water solubility and compensating for knowledge and experimental gaps. Modeling of sensory irritation would be a better 'empirical' starting point for derivation of AFs for children, older, and sick people, as human exposure studies are not possible (due to ethical reasons) or not generalizable (due to self-selection). Dedicated AFs may be derived for environments where dry air, high room temperature, and visually demanding tasks aggravate the eyes or airways than for places in which the workload is balanced, while indoor playgrounds might need other AFs due to physical workload and affected groups of the general population.
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Affiliation(s)
- Stefan Kleinbeck
- Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
| | - Peder Wolkoff
- National Research Centre for the Working Environment, Copenhagen, Denmark
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Bazan HEP, Pham TL. A new R,R-RvD6 isomer with protective actions following corneal nerve injury. Prostaglandins Other Lipid Mediat 2024; 170:106802. [PMID: 38036037 DOI: 10.1016/j.prostaglandins.2023.106802] [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: 09/15/2023] [Revised: 11/05/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023]
Abstract
The transparent cornea is the most densely innervated tissue in the body, primarily by sensory nerves originating from the trigeminal ganglia (TG). Damage to corneal nerves reduces sensitivity and tear secretion and results in dry eye. Consequently, ocular pain, for which no satisfactory therapies exist, arises in many cases. Treatment of injured corneas with pigment epithelium-derived factor (PEDF) combined with docosahexaenoic acid (DHA) stimulates nerve regeneration in models of refractive surgery, which damages nerves. The mechanism involves the synthesis of a stereoisomer of resolvin D6 (R,R-RvD6) formed after incorporating DHA into membrane lipids. Activation of a PEDF receptor (PEDF-R) with phospholipase activity releases DHA to synthesize the new resolvin isomer, which is secreted via tears. Topical treatment of mice corneas with R,R-RvD6 shows higher bioactivity in regenerating nerves and increasing sensitivity compared to PEDF+DHA. It also stimulates a transcriptome in the TG that modulates genes involved in ocular pain. Our studies suggest an important therapeutic role for R,R-RvD6 in regenerating corneal nerves and decreasing pain resulting from dry eye.
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Affiliation(s)
- Haydee E P Bazan
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health Sciences Center New Orleans, New Orleans, LA, USA.
| | - Thang L Pham
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health Sciences Center New Orleans, New Orleans, LA, USA.
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Buonfiglio F, Wasielica-Poslednik J, Pfeiffer N, Gericke A. Diabetic Keratopathy: Redox Signaling Pathways and Therapeutic Prospects. Antioxidants (Basel) 2024; 13:120. [PMID: 38247544 PMCID: PMC10812573 DOI: 10.3390/antiox13010120] [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: 12/19/2023] [Revised: 01/10/2024] [Accepted: 01/16/2024] [Indexed: 01/23/2024] Open
Abstract
Diabetes mellitus, the most prevalent endocrine disorder, not only impacts the retina but also significantly involves the ocular surface. Diabetes contributes to the development of dry eye disease and induces morphological and functional corneal alterations, particularly affecting nerves and epithelial cells. These changes manifest as epithelial defects, reduced sensitivity, and delayed wound healing, collectively encapsulated in the context of diabetic keratopathy. In advanced stages of this condition, the progression to corneal ulcers and scarring further unfolds, eventually leading to corneal opacities. This critical complication hampers vision and carries the potential for irreversible visual loss. The primary objective of this review article is to offer a comprehensive overview of the pathomechanisms underlying diabetic keratopathy. Emphasis is placed on exploring the redox molecular pathways responsible for the aberrant structural changes observed in the cornea and tear film during diabetes. Additionally, we provide insights into the latest experimental findings concerning potential treatments targeting oxidative stress. This endeavor aims to enhance our understanding of the intricate interplay between diabetes and ocular complications, offering valuable perspectives for future therapeutic interventions.
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Affiliation(s)
- Francesco Buonfiglio
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (J.W.-P.); (N.P.)
| | | | | | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (J.W.-P.); (N.P.)
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Yang Y, Zhong J, Cui D, Jensen LD. Up-to-date molecular medicine strategies for management of ocular surface neovascularization. Adv Drug Deliv Rev 2023; 201:115084. [PMID: 37689278 DOI: 10.1016/j.addr.2023.115084] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 09/11/2023]
Abstract
Ocular surface neovascularization and its resulting pathological changes significantly alter corneal refraction and obstruct the light path to the retina, and hence is a major cause of vision loss. Various factors such as infection, irritation, trauma, dry eye, and ocular surface surgery trigger neovascularization via angiogenesis and lymphangiogenesis dependent on VEGF-related and alternative mechanisms. Recent advances in antiangiogenic drugs, nanotechnology, gene therapy, surgical equipment and techniques, animal models, and drug delivery strategies have provided a range of novel therapeutic options for the treatment of ocular surface neovascularization. In this review article, we comprehensively discuss the etiology and mechanisms of corneal neovascularization and other types of ocular surface neovascularization, as well as emerging animal models and drug delivery strategies that facilitate its management.
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Affiliation(s)
- Yunlong Yang
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.
| | - Junmu Zhong
- Department of Ophthalmology, Longyan First Hospital Affiliated to Fujian Medical University, Longyan 364000, Fujian Province, China
| | - Dongmei Cui
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen 518040, Guangdong Province, China
| | - Lasse D Jensen
- Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine, Unit of Cardiovascular Medicine, Linköping University, Linköping, Sweden.
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Posarelli M, Chirapapaisan C, Muller R, Abbouda A, Pondelis N, Cruzat A, Cavalcanti BM, Cox SM, Jamali A, Pavan-Langston D, Hamrah P. Corneal nerve regeneration is affected by scar location in herpes simplex keratitis: A longitudinal in vivo confocal microscopy study. Ocul Surf 2023; 28:42-52. [PMID: 36646165 DOI: 10.1016/j.jtos.2023.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 10/28/2022] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
PURPOSE To assess the effect of corneal scar location on corneal nerve regeneration in patients with herpes simplex virus (HSV) keratitis in their affected and contralateral eyes over a 1-year period by in vivo confocal microscopy (IVCM), and to correlate these findings to corneal sensation measured by Cochet-Bonnet Esthesiometer. METHODS Prospective, longitudinal, case-control study. Bilateral corneal nerve density and corneal sensation were analyzed centrally and peripherally in 24 healthy controls and 23 patients with unilateral HSV-related corneal scars using IVCM. RESULTS In the central scar (CS) group, total nerve density in the central cornea remained significantly lower compared to controls at follow-up (11.05 ± 1.97mm/mm2, p < 0.001), and no significant nerve regeneration was observed (p = 0.090). At follow-up, total nerve density was not significantly different from controls in the central and peripheral cornea of the peripheral scar (PS) group (all p > 0.05), but significant nerve regeneration was observed in central corneas (16.39 ± 2.39mm/mm2, p = 0.007) compared to baseline. In contralateral eyes, no significant corneal nerve regeneration was observed in central or peripheral corneas of patients with central scars or peripheral scars at 1-year follow-up, compared to baseline (p > 0.05). There was a positive correlation between corneal nerve density and sensation in both central (R = 0.53, p < 0.0001) and peripheral corneas (R = 0.27, p = 0.0004). In the CS group, the corneal sensitivity was <4 cm in 4 (30.8%) and 7 (53.8%) patients in the central and peripheral corneas at baseline, and in 5 (38.5%) and 2 subjects (15.4%) at follow-up, whereas in the PS group only 1 patient (10%) showed a corneal sensation < 4 cm in the central cornea at baseline, and only 1 (10.0%), 3 (30.0%) and 1 (10.0%) patients at follow-up in the central, affected and opposite area of the cornea, respectively. CONCLUSION The location of HSV scarring in the cornea affects the level of corneal nerve regeneration. Eyes with central corneal scar have a diminished capacity to regenerate nerves in central cornea, show a more severe reduction in corneal sensation in the central and peripheral corneas that persist at follow-up, and have a reduced capability to restore the corneal sensitivity above the cut-off of 4 cm. Thus, clinicians should be aware that CS patients would benefit from closer monitoring for potential complications associated with neurotrophic keratopathy, as they have a lower likelihood for nerve regeneration.
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Affiliation(s)
- Matteo Posarelli
- Center for Translational Ocular Immunology, USA; Cornea Service, New England Eye Center, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Chareenun Chirapapaisan
- Ocular Surface Imaging Center, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Rodrigo Muller
- Center for Translational Ocular Immunology, USA; Cornea Service, New England Eye Center, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA; Ocular Surface Imaging Center, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Alessandro Abbouda
- Center for Translational Ocular Immunology, USA; Cornea Service, New England Eye Center, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | | | - Andrea Cruzat
- Ocular Surface Imaging Center, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Department of Ophthalmology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Bernardo M Cavalcanti
- Ocular Surface Imaging Center, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | | | - Arsia Jamali
- Center for Translational Ocular Immunology, USA; Ocular Surface Imaging Center, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Deborah Pavan-Langston
- Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology, USA; Cornea Service, New England Eye Center, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA; Ocular Surface Imaging Center, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
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Corneal Neurotization—Indications, Surgical Techniques and Outcomes. J Clin Med 2023; 12:jcm12062214. [PMID: 36983215 PMCID: PMC10059768 DOI: 10.3390/jcm12062214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/05/2023] [Accepted: 03/11/2023] [Indexed: 03/16/2023] Open
Abstract
Corneal neurotization is a promising surgical approach for the treatment of moderate to severe neurotrophic keratopathy. This technique aims to restore corneal sensation by transferring healthy nerves, either directly or via a conduit, to the anesthetic cornea. This review provides a report on the current state of development, evidence, and experience in the field. We summarize the data available from clinical reports and case series, placing an emphasis on the diversity of the surgical techniques reported. While these data are encouraging, they also highlight the need for a consensus in reporting outcomes and highlight how the next step will involve validating putative outcome parameters when researching and reporting corneal neurotization surgery.
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McNutt P. Progress towards a standardized model of ocular sulfur mustard injury for therapeutic testing. Exp Eye Res 2023; 228:109395. [PMID: 36731603 PMCID: PMC9975063 DOI: 10.1016/j.exer.2023.109395] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/25/2023] [Accepted: 01/28/2023] [Indexed: 02/01/2023]
Abstract
Sulfur mustard (SM) remains a highly dangerous chemical weapon capable of producing mass casualties through liquid or vapor exposure. The cornea is highly sensitive to SM toxicity and exposure to low vapor doses can cause incapacitating acute injuries. At higher doses, corneas fail to fully heal and subsequently develop a constellation of symptoms known as mustard gas keratopathy (MGK) that causes reduced quality of life and impaired or lost vision. Despite a century of research, there are no specific treatments for acute or persistent ocular SM injuries. Here I summarize toxicological, clinical and pathophysiological mechanisms of SM vapor injury in the cornea, describe a preclinical model of ocular SM vapor exposure for reproducible therapeutic studies, and propose new approaches to improve evaluation of therapeutic effects. I also describe recent findings illustrating the delayed development of a transient but severe recurrent corneal lesion that, in turn, triggers the emergence of secondary keratopathies characteristic of the chronic form of MGK. Development of this recurrent lesion is SM dose-dependent, although the severity of the recurrent lesion appears SM dose-independent. Similar recurrent lesions have been reported in multiple species, including humans. Given the mechanistic relationship between the recurrent lesion and chronic, secondary keratopathies, I hypothesize that preventing the development of the recurrent lesion represents a novel and potentially valuable therapeutic approach for treatment of severe corneal SM injuries. Although ocular exposure to SM vapor continues to be a challenging therapeutic target, establishing consistent and reproducible models of corneal injury that enhance mechanistic and pathophysiological understanding will help satisfy regulatory requirements and accelerate the development of effective therapies.
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Affiliation(s)
- Patrick McNutt
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, 391 Technology Way, Winston Salem, NC, 27101, USA.
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Bucolo C, Maugeri G, Giunta S, D’Agata V, Drago F, Romano GL. Corneal wound healing and nerve regeneration by novel ophthalmic formulations based on cross-linked sodium hyaluronate, taurine, vitamin B6, and vitamin B12. Front Pharmacol 2023; 14:1109291. [PMID: 36817120 PMCID: PMC9932323 DOI: 10.3389/fphar.2023.1109291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Introduction: To evaluate the pharmacological profile of ocular formulations based on cross-linked sodium hyaluronate (CL-SH), taurine (Tau), vitamin B6 (Vit B6) and vitamin B12 (Vit B12) using in vitro and in vivo paradigms. Methods: Rabbit corneal epithelial cells were used to assess wound healing and reactive oxygen species (ROS) formation by scratch assay and oxidative stress (0.3 mM H2O2; 30 min), respectively with or without ocular formulations exposure. In vivo studies were carried out on albino rabbits to evaluate corneal nerve regeneration and corneal wound healing with or without treatment with six different formulations. Animals were anesthetized, the corneal epithelium was removed, and formulations were topically administered (30 μL/eye; 3 times/day for 6 days). Slit-lamp observation was carried out at different time points. After 6 days the animals were killed, and corneas were collected to evaluate corneal re-innervation by immunohistochemistry of selective neuronal marker β-III tubulin. Results: Formulations containing the concentrations 0.16% or 0.32% of cross-linked sodium hyaluronate, taurine, vitamin B6 and vitamin B12 accelerated corneal wound healing. Cells exposed to H2O2 led to significant (p < 0.05) increase of reactive oxygen species concentration that was significantly (p < 0.05) counteract by formulations containing cross-linked sodium hyaluronate (0.32%) and taurine with or without vitamins. The extent of re-innervation, in terms of β-III tubulin staining, was 5-fold greater (p < 0.01) in the eye of rabbits treated with formulation containing 0.32% cross-linked sodium hyaluronate, taurine, vitamins (RenerviX®) compared with the control group (no treatment). Furthermore, re-innervation elicited by RenerviX® was significantly greater (p < 0.01) compared with the group treated with the formulation containing 0.32% cross-linked sodium hyaluronate and taurine without vitamins, and with the group treated with the formulation containing 0.5% linear sodium hyaluronate (SH), taurine, and vitamin B12, respectively. Discussion: In conclusion, among the formulations tested, the new ophthalmic gel RenerviX® was able to contrast oxidative stress, to accelerate corneal re-epithelization and to promote nerve regeneration.
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Affiliation(s)
- Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy,*Correspondence: Claudio Bucolo,
| | - Grazia Maugeri
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Salvatore Giunta
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Velia D’Agata
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Giovanni Luca Romano
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
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Schwend T. Wiring the ocular surface: A focus on the comparative anatomy and molecular regulation of sensory innervation of the cornea. Differentiation 2023:S0301-4681(23)00010-5. [PMID: 36997455 DOI: 10.1016/j.diff.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/23/2023] [Indexed: 01/29/2023]
Abstract
The cornea is richly innervated with sensory nerves that function to detect and clear harmful debris from the surface of the eye, promote growth and survival of the corneal epithelium and hasten wound healing following ocular disease or trauma. Given their importance to eye health, the neuroanatomy of the cornea has for many years been a source of intense investigation. Resultantly, complete nerve architecture maps exist for adult human and many animal models and these maps reveal few major differences across species. Interestingly, recent work has revealed considerable variation across species in how sensory nerves are acquired during developmental innervation of the cornea. Highlighting such species-distinct key differences, but also similarities, this review provides a full, comparative anatomy analysis of sensory innervation of the cornea for all species studied to date. Further, this article comprehensively describes the molecules that have been shown to guide and direct nerves toward, into and through developing corneal tissue as the final architectural pattern of the cornea's neuroanatomy is established. Such knowledge is useful for researchers and clinicians seeking to better understand the anatomical and molecular basis of corneal nerve pathologies and to hasten neuro-regeneration following infection, trauma or surgery that damage the ocular surface and its corneal nerves.
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12
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Batista A, Guimarães P, Domingues JP, Quadrado MJ, Morgado AM. Two-Photon Imaging for Non-Invasive Corneal Examination. SENSORS (BASEL, SWITZERLAND) 2022; 22:9699. [PMID: 36560071 PMCID: PMC9783858 DOI: 10.3390/s22249699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
Two-photon imaging (TPI) microscopy, namely, two-photon excited fluorescence (TPEF), fluorescence lifetime imaging (FLIM), and second-harmonic generation (SHG) modalities, has emerged in the past years as a powerful tool for the examination of biological tissues. These modalities rely on different contrast mechanisms and are often used simultaneously to provide complementary information on morphology, metabolism, and structural properties of the imaged tissue. The cornea, being a transparent tissue, rich in collagen and with several cellular layers, is well-suited to be imaged by TPI microscopy. In this review, we discuss the physical principles behind TPI as well as its instrumentation. We also provide an overview of the current advances in TPI instrumentation and image analysis. We describe how TPI can be leveraged to retrieve unique information on the cornea and to complement the information provided by current clinical devices. The present state of corneal TPI is outlined. Finally, we discuss the obstacles that must be overcome and offer perspectives and outlooks to make clinical TPI of the human cornea a reality.
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Affiliation(s)
- Ana Batista
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
| | - Pedro Guimarães
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - José Paulo Domingues
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
| | - Maria João Quadrado
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - António Miguel Morgado
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
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13
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Bian Y, Ma KK, Hall NE, Elze T, Lorch A, Miller JW, Dana R, Yin J. Neurotrophic Keratopathy in the United States: An Intelligent Research in Sight Registry Analysis. Ophthalmology 2022; 129:1255-1262. [PMID: 35768054 DOI: 10.1016/j.ophtha.2022.06.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 12/27/2022] Open
Abstract
PURPOSE To describe the characteristics of neurotrophic keratopathy (NK) in the United States. DESIGN Retrospective database study. PARTICIPANTS Thirty-one thousand nine hundred fifteen eyes of 27 483 patients with a diagnosis of NK. METHODS Retrospective analysis of visits associated with a diagnosis of NK between 2013 and 2018 using the American Academy of Ophthalmology Intelligent Research in Sight (IRIS®) Registry. MAIN OUTCOME MEASURES Demographic information, prevalence, visual acuity (VA), concomitant diagnosis and procedure codes, and risk factors impacting VA most closely after NK onset date. RESULTS Mean ± standard deviation (SD) age at initial diagnosis of NK was 68.0 ± 16.0 years, and 58.91% of patients were women (P < 0.0001). Presentation was unilateral in 58.14%, bilateral in 16.13%, and unspecified in 25.73%. Average 6-year prevalence of NK in the IRIS Registry was 21.34 cases per 100 000 patients. Mean ± SD VA was 0.60 ± 0.79 logMAR before diagnosis and 0.88 ± 0.94 logMAR after diagnosis (P < 0.0001). Most common concomitant diagnoses included herpetic keratitis (33.70%), diabetes (31.59%), and corneal dystrophy (14.28%). Common procedures for NK management included the use of amniotic membrane (29.90%), punctal plugs (29.65%), and bandage contact lenses (22.67%). Age, male sex, Black race, Hispanic or Latino ethnicity, unilateral involvement, concomitant diagnoses of diabetes, corneal transplantation, and herpetic keratitis were associated significantly with worse VA. CONCLUSIONS Based on the IRIS Registry, the prevalence of NK is 21.34 cases per 100 000 patients. Visual acuity was significantly worse after NK diagnosis compared with other time points. Neurotrophic keratopathy was associated most commonly with herpetic keratitis and diabetes. Worse VA in patients with NK was associated with several demographic characteristics, history of diabetes, corneal transplantation, and herpetic keratitis.
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Affiliation(s)
- Yandong Bian
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Kevin K Ma
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Nathan E Hall
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Tobias Elze
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Alice Lorch
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Joan W Miller
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Reza Dana
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Jia Yin
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts.
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14
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He J, Pham TL, Bazan HEP. Neuroanatomy of Adult and Aging Chicken Cornea. Curr Eye Res 2022; 47:1374-1380. [PMID: 35904450 PMCID: PMC9844890 DOI: 10.1080/02713683.2022.2104321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/05/2022] [Accepted: 07/15/2022] [Indexed: 01/19/2023]
Abstract
PURPOSE To provide a complete nerve architecture and main sensory neuropeptide distribution in the chicken cornea. METHODS Adult chickens aged 6 months and 4 years were used. The whole cornea was stained with protein gene product (PGP) 9.5 antibody-a pan marker for nerve fibers, calcitonin gene-related peptide (CGRP), and substance P (SP) antibodies; whole-mount images were acquired to build an entire view of corneal innervation. Relative corneal epithelial nerve fiber densities, including subbasal bundles and superficial terminals, were assessed by computer-assisted analysis. RESULTS An average of about 76.3 ± 5.7 (n = 8 corneas, 4 M/4F) stromal nerve trunks enter the cornea radially and are evenly distributed around the limbus with no significant difference between male and female chickens. The subbasal nerve bundles do not extend in a given direction and, as a result, do not form a vortex in the center of the cornea. Furthermore, the chicken cornea contains more SP-positive nerves than CGRP-positive nerves. It is also shown that aging significantly reduces corneal epithelial nerve density in chickens. CONCLUSIONS This is the first study to provide a complete map of the entire corneal nerves and CGRP and SP sensory neuropeptide distribution in the adult chicken cornea. The findings show chicken corneal innervation has many differences to human and mammal cornea.
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Affiliation(s)
- Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
- Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
| | - Thang Luong Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
| | - Haydee E. P. Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
- Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, USA
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15
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Asiedu K. Role of ocular surface neurobiology in neuronal-mediated inflammation in dry eye disease. Neuropeptides 2022; 95:102266. [PMID: 35728484 DOI: 10.1016/j.npep.2022.102266] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 01/18/2023]
Abstract
Inflammation is the consequence of dry eye disease regardless of its etiology. Several injurious or harmless processes to the ocular surface neurons promote ocular surface neurogenic inflammation, leading to the vicious cycle of dry eye disease. These processes include the regular release of neuromediators during the conduction of ocular surface sensations, hyperosmolarity-induced ocular surface neuronal damage, neuro-regenerative activities, and neuronal-mediated dendritic cell activities. Neurogenic inflammation appears to be the main culprit, instigating the self-perpetuating inflammation observed in patients with dry eye disease.
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Affiliation(s)
- Kofi Asiedu
- School of Optometry & Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, Australia.
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16
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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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17
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Cui Z, Liao K, Li S, Gu J, Wang Y, Ding C, Guo Y, Chan HF, Ma JH, Tang S, Chen J. LM22B-10 promotes corneal nerve regeneration through in vitro 3D co-culture model and in vivo corneal injury model. Acta Biomater 2022; 146:159-176. [PMID: 35562005 DOI: 10.1016/j.actbio.2022.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/21/2022] [Accepted: 05/05/2022] [Indexed: 11/01/2022]
Abstract
Corneal nerve wounding often causes abnormalities in the cornea and even blindness in severe cases. In this study, we construct a dorsal root ganglion-corneal stromal cell (DRG-CSC, DS) co-culture 3D model to explore the mechanism of corneal nerve regeneration. Firstly, this model consists of DRG collagen grafts sandwiched by orthogonally stacked and orderly arranged CSC-laden plastic compressed collagen. Nerve bundles extend into the entire corneal stroma within 14 days, and they also have orthogonal patterns. This nerve prevents CSCs from apoptosis in the serum withdrawal medium. The conditioned medium (CM) for CSCs in collagen scaffolds contains NT-3, IL-6, and other factors. Among them, NT-3 notably promotes the activation of ERK-CREB in the DRG, leading to the growth of nerve bundles, and IL-6 induces the upregulation of anti-apoptotic genes. Then, LM22B-10, an activator of the NT-3 receptor TrkB/TrkC, can also activate ERK-CREB to enhance nerve growth. After administering LM22B-10 eye drops to regular and diabetic mice with corneal wounding, LM22B-10 significantly improves the healing speed of the corneal epithelium, corneal sensitivity, and corneal nerve density. Overall, the DS co-culture model provides a promising platform and tools for the exploration of corneal physiological and pathological mechanisms, as well as the verification of drug effects in vitro. Meanwhile, we confirm that LM22B-10, as a non-peptide small molecule, has future potential in nerve wound repair. STATEMENT OF SIGNIFICANCE: The cornea accounts for most of the refractive power of the eye. Corneal nerves play an important role in maintaining corneal homeostasis. Once the corneal nerves are damaged, the corneal epithelium and stroma develop lesions. However, the mechanism of the interaction between corneal nerves and corneal cells is still not fully understood. Here, we construct a corneal stroma-nerve co-culture in vitro model and reveal that NT-3 expressed by stromal cells promotes nerve growth by activating the ERK-CREB pathway in nerves. LM22B-10, an activator of NT-3 receptors, can also induce nerve growth in vitro. Moreover, it is used as eye drops to enhance corneal epithelial wound healing, corneal nerve sensitivity and density of nerve plexus in corneal nerve wounding model in vivo.
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Aghamirsalim M, Mobaraki M, Soltani M, Kiani Shahvandi M, Jabbarvand M, Afzali E, Raahemifar K. 3D Printed Hydrogels for Ocular Wound Healing. Biomedicines 2022; 10:biomedicines10071562. [PMID: 35884865 PMCID: PMC9313212 DOI: 10.3390/biomedicines10071562] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/24/2022] [Accepted: 06/26/2022] [Indexed: 12/21/2022] Open
Abstract
Corneal disease is one of the most significant causes of blindness around the world. Presently, corneal transplantation is the only way to treat cornea blindness. It should be noted that the amount of cornea that people donate is so much less than that required (1:70). Therefore, scientists have tried to resolve this problem with tissue engineering and regenerative medicine. Fabricating cornea with traditional methods is difficult due to their unique properties, such as transparency and geometry. Bioprinting is a technology based on additive manufacturing that can use different biomaterials as bioink for tissue engineering, and the emergence of 3D bioprinting presents a clear possibility to overcome this problem. This new technology requires special materials for printing scaffolds with acceptable biocompatibility. Hydrogels have received significant attention in the past 50 years, and they have been distinguished from other materials because of their unique and outstanding properties. Therefore, hydrogels could be a good bioink for the bioprinting of different scaffolds for corneal tissue engineering. In this review, we discuss the use of different types of hydrogel for bioink for corneal tissue engineering and various methods that have been used for bioprinting. Furthermore, the properties of hydrogels and different types of hydrogels are described.
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Affiliation(s)
- Mohamadreza Aghamirsalim
- Translational Ophthalmology Research Center, Tehran University of Medical Science, Tehran 14176-14411, Iran; (M.A.); (M.J.)
| | - Mohammadmahdi Mobaraki
- Department of Biomedical Engineering, Amirkabir University of Technology, Tehran P.O. Box 15875-4413, Iran;
| | - Madjid Soltani
- Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran 19967-15433, Iran;
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Advanced Bioengineering Initiative Center, Multidisciplinary International Complex, K. N. Toosi University of Technology, Tehran 14176-14411, Iran
- Centre for Biotechnology and Bioengineering (CBB), University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Correspondence:
| | - Mohammad Kiani Shahvandi
- Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran 19967-15433, Iran;
| | - Mahmoud Jabbarvand
- Translational Ophthalmology Research Center, Tehran University of Medical Science, Tehran 14176-14411, Iran; (M.A.); (M.J.)
| | - Elham Afzali
- Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Science, Kerman 76169-13555, Iran;
| | - Kaamran Raahemifar
- Data Science and Artificial Intelligence Program, College of Information Sciences and Technology (IST), Penn State University, State College, PA 16801, USA;
- Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
- Faculty of Science, School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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Frutos-Rincón L, Gómez-Sánchez JA, Íñigo-Portugués A, Acosta MC, Gallar J. An Experimental Model of Neuro-Immune Interactions in the Eye: Corneal Sensory Nerves and Resident Dendritic Cells. Int J Mol Sci 2022; 23:ijms23062997. [PMID: 35328417 PMCID: PMC8951464 DOI: 10.3390/ijms23062997] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/28/2022] [Accepted: 03/04/2022] [Indexed: 12/04/2022] Open
Abstract
The cornea is an avascular connective tissue that is crucial, not only as the primary barrier of the eye but also as a proper transparent refractive structure. Corneal transparency is necessary for vision and is the result of several factors, including its highly organized structure, the physiology of its few cellular components, the lack of myelinated nerves (although it is extremely innervated), the tightly controlled hydration state, and the absence of blood and lymphatic vessels in healthy conditions, among others. The avascular, immune-privileged tissue of the cornea is an ideal model to study the interactions between its well-characterized and dense sensory nerves (easily accessible for both focal electrophysiological recording and morphological studies) and the low number of resident immune cell types, distinguished from those cells migrating from blood vessels. This paper presents an overview of the corneal structure and innervation, the resident dendritic cell (DC) subpopulations present in the cornea, their distribution in relation to corneal nerves, and their role in ocular inflammatory diseases. A mouse model in which sensory axons are constitutively labeled with tdTomato and DCs with green fluorescent protein (GFP) allows further analysis of the neuro-immune crosstalk under inflammatory and steady-state conditions of the eye.
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Affiliation(s)
- Laura Frutos-Rincón
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- The European University of Brain and Technology-NeurotechEU, 03550 San Juan de Alicante, Spain
| | - José Antonio Gómez-Sánchez
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- Correspondence: ; Tel.: +34-965-91-9594
| | - Almudena Íñigo-Portugués
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
| | - M. Carmen Acosta
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- The European University of Brain and Technology-NeurotechEU, 03550 San Juan de Alicante, Spain
| | - Juana Gallar
- Instituto de Neurociencias, Universidad Miguel Hernández—Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain; (L.F.-R.); (A.Í.-P.); (M.C.A.); (J.G.)
- The European University of Brain and Technology-NeurotechEU, 03550 San Juan de Alicante, Spain
- Instituto de Investigación Biomédica y Sanitaria de Alicante, 03010 Alicante, Spain
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Cao J, Qu J, Odilov B, Lu B, Zhang Y, Li L, Zhang Y, Xiong Q, Hong Y, Li J, Shen Y, Hou X. Corneal Nerve Parameter Reference Values for Chinese Adults Assessed by Corneal Confocal Microscopy. J Diabetes Res 2022; 2022:4913031. [PMID: 35265718 PMCID: PMC8898861 DOI: 10.1155/2022/4913031] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 02/09/2022] [Indexed: 11/18/2022] Open
Abstract
Background Confocal corneal microscopy is an excellent new noninvasive tool for assessing diabetic peripheral neuropathy. We aimed to investigate the clinical variables associated with corneal nerve parameters and establish reference values for clinical use in healthy Chinese adults. Methods The study enlisted 257 healthy volunteers (137 females and 120 males) from two clinical academic centers in China. Two experts captured and selected images of the central corneal subbasal nerve plexus at each center using the same corneal confocal microscopy instrument according to a commonly adopted protocol. Corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fiber length (CNFL) were measured using fully automated software (ACCMetrics). The correlation between clinical indicators and confocal corneal microscopy measures was determined using partial correlation. Quantile regression was used to calculate reference values and estimate the effects of clinical factors on the normative values of confocal corneal microscopy measures. Results Females had significantly higher CNFD, CNBD, and CNFL than males. There was no correlation between age, glycated hemoglobin (HbA1c), height, weight, body mass index (BMI), and any corneal nerve fiber parameter in both sexes. In either sex, age, weight, height, BMI, and HbA1c did not affect the 0.05th quantile values of any corneal nerve parameter. Conclusions This study establishes sex-adjusted reference values for corneal confocal microscopy measures in Chinese adults and provides a reference for clinical practice and research with this technique.
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Affiliation(s)
- Juan Cao
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Department of Health Management Center, Qilu Hospital of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Jingru Qu
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Jinan Clinical Research Center for Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Bekzod Odilov
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Bin Lu
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, 12 Wulumuqi Middle Road, Shanghai 200040, China
| | - Yuanpin Zhang
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University, 12 Wulumuqi Middle Road, Shanghai 200040, China
| | - Lili Li
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Department of Ultrasound, Qilu Hospital of Shandong University, 758 Hefei Road, Qingdao, Shandong 266000, China
| | - Yuan Zhang
- Clinical Epidemiology Unit, Qilu Hospital of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Clinical Research Center of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Qian Xiong
- Department of Endocrinology and Metabolism, Gonghui Hospital, 315 Shimen No. 1 Road, Shanghai 200040, China
| | - Yu Hong
- Department of Endocrinology and Metabolism, Gonghui Hospital, 315 Shimen No. 1 Road, Shanghai 200040, China
| | - Jianqiao Li
- Department of Ophthalmology, Qilu Hospital of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
| | - Yunfeng Shen
- Department of Endocrinology and Metabolism, Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, The Second Affiliated Hospital of Nanchang University, 1 Minde Road, Nanchang, Jiangxi 330006, China
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
- Jinan Clinical Research Center for Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, 107 Wenhua W Road, Jinan, Shandong 250012, China
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Lasagni Vitar RM, Bonelli F, Rama P, Ferrari G. Immunity and pain in the eye: focus on the ocular surface. Clin Exp Immunol 2021; 207:149-163. [PMID: 35020868 PMCID: PMC8982975 DOI: 10.1093/cei/uxab032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/21/2021] [Accepted: 12/10/2021] [Indexed: 02/03/2023] Open
Abstract
Most ocular diseases are associated with pain. While pain has been generally considered a mere (deleterious) additional symptom, it is now emerging that it is a key modulator of innate/adaptive immunity. Because the cornea receives the highest nerve density of the entire body, it is an ideal site to demonstrate interactions between pain and the immune response. Indeed, most neuropeptides involved in pain generation are also potent regulators of innate and adaptive leukocyte physiology. On the other hand, most inflammatory cells can modulate the generation of ocular pain through release of specific mediators (cytokines, chemokines, growth factors, and lipid mediators). This review will discuss the reciprocal role(s) of ocular surface (and specifically: corneal) pain on the immune response of the eye. Finally, we will discuss the clinical implications of such reciprocal interactions in the context of highly prevalent corneal diseases.
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Affiliation(s)
- Romina Mayra Lasagni Vitar
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Filippo Bonelli
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Rama
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giulio Ferrari
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy,Correspondence: Giulio Ferrari, Cornea and Ocular Surface Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy. E-mail:
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Liu Z, Yu C, Song Y, Pang M, Jin Y. The Clinical Guiding Role of the Distribution of Corneal Nerves in the Selection of Incision for Penetrating Corneal Surgery in Canines. Vet Sci 2021; 8:vetsci8120313. [PMID: 34941840 PMCID: PMC8704701 DOI: 10.3390/vetsci8120313] [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: 10/24/2021] [Revised: 11/20/2021] [Accepted: 12/06/2021] [Indexed: 11/16/2022] Open
Abstract
The cornea is one of the regions with the highest density of nerve terminals in the animal body and it bears such functions as nourishing the cornea and maintaining corneal sensation. In veterinary clinical practice, the corneoscleral limbus incision is frequently applied in cataract surgery, peripheral iridectomy, and other procedures for glaucoma. Inevitably, it would cause damage to the nerve roots that enter the cornea from the corneal limbus, thus inducing a series of complications. In this paper, the in vitro cornea (39 corneas from 23 canines, with ages ranging from 8 months old to 3 years old, including 12 male canines and 11 female canines) was divided into 6 zones, and the whole cornea was stained with gold chloride. After staining, corneal nerves formed neural networks at different levels of cornea. There was no significant difference in the number of nerve roots at the corneoscleral limbus between different zones (F = 1.983, p = 0.082), and the nerve roots at the corneoscleral limbus (mean value, 24.43; 95% CI, 23.43-25.42) were evenly distributed. Additionally, there was no significant difference in the number of corneal nerve roots between male and female canines (p = 0.143). There was also no significant difference in the number of corneal nerve roots between adult canines and puppies (p = 0.324). The results of the above analysis will provide a reasonable anatomical basis for selecting the incision location and orientation of penetrating surgery for the canine cornea in veterinary practice.
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İnaltekin A, Bozkurt E, Kıvrak Y. Factors Associated with Pain Level in Patients Receiving Intravitreal Injection. J Curr Ophthalmol 2021; 33:323-329. [PMID: 34765822 PMCID: PMC8579782 DOI: 10.4103/joco.joco_6_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/10/2021] [Accepted: 05/13/2021] [Indexed: 11/25/2022] Open
Abstract
Purpose: To identify the factors associated with the pain level in patients receiving intravitreal injection. Methods: A total of 120 patients were prospectively evaluated, and 104 were included in the study. Patients were asked to rate their pain intensity from 0 to 10 on the visual analog scale. Factors that were possibly associated with pain level were evaluated using a sociodemographic data form, state anxiety inventory, and the hospital anxiety and depression scale. Results: Of the participants, 54 (51.9%) were female, and 50 (48.1%) were male, with a mean age of 65 ± 9.01 years. There was a positive correlation between pain level and state anxiety scores (r = 0.30; P < 0.001) and a negative correlation between hospital anxiety score (r = −0.23; P = 0.02) and hospital depression score (r = −0.27; P = 0.01). The correlation between pain score and education level was significantly higher in primary and secondary school graduates (P < 0.01). Smokers were observed to have higher pain scores (6.50 ± 2.21 in smokers and 4.87 ± 2.50 in nonsmokers; P = 0.01). Among diagnostic groups, pain scores were found to be significantly lower in the diabetic retinopathy (DR) group (6.82 ± 1.99 in age-related macular degeneration, 5.94 ± 2.27 in retinal vein occlusion, and 3.58 ± 1.97 in DR; P < 0.001). When pain scores were evaluated according to the drug injected, the group receiving bevacizumab injection was observed to have higher pain scores (7.32 ± 1.81 in bevacizumab, 4.00 ± 2.08 in aflibercept, and 3.92 ± 1.96 in ranibizumab; P < 0.001). Based on the multiple regression analysis, the state anxiety score, hospital anxiety score, hospital depression score, and smoking status were observed not to be significant predictors. The level of education, diagnosis, and active substance were found to have a statistically significant effect on pain perception. Conclusion: In this study, pain levels have been found to be high in smokers, those with a low educational level, individuals receiving bevacizumab for intravitreal injection, and those having a higher level of state anxiety, whereas patients with DR have lower pain scores.
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Affiliation(s)
- Ali İnaltekin
- Department of Psychiatry, Oltu State Hospital, Erzurum, Turkey
| | - Erdinç Bozkurt
- Department of Ophthalmology, Umraniye Training and Research Hospital, İstanbul, Turkey
| | - Yüksel Kıvrak
- Department of Psychiatry, Afyonkarahisar Health Sciences University School of Medicine, Afyonkarahisar, Turkey
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Schenk MS, Wartak A, Buehler V, Zhao J, Tearney GJ, Birngruber R, Kassumeh S. Advances in Imaging of Subbasal Corneal Nerves With Micro-Optical Coherence Tomography. Transl Vis Sci Technol 2021; 10:22. [PMID: 34779835 PMCID: PMC8606792 DOI: 10.1167/tvst.10.13.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the most peripheral corneal nerve plexus using high-resolution micro-optical coherence tomography (µOCT) imaging and to assess µOCT's clinical potential as a screening tool for corneal and systemic diseases. Methods An experimental high-resolution (1.5 × 1.5 × 1 µm) µOCT setup was applied for three-dimensional imaging of the subbasal nerve plexus in nonhuman primates (NHPs) and swine within 3 hours postmortem. Morphologic features of subbasal nerves in µOCT were compared to β3 tubulin-stained fluorescence confocal microscopy (FCM). Parameters such as nerve density, nerve distribution, and imaging repeatability were evaluated, using semiautomatic image analysis in form of a custom corneal surface segmentation algorithm and NeuronJ. Results Swine and NHP corneas showed the species-specific nerve morphology in both imaging modalities. Most fibers showed a linear course, forming a highly parallel pattern, converging in a vortex with overall nerve densities varying between 9.51 and 24.24 mm/mm2. The repeatability of nerve density quantification of the µOCT scans as approximately 88% in multiple image recordings of the same cornea. Conclusions Compared to the current gold standard of FCM, µOCT's larger field of view of currently 1 × 1 mm increases the conclusiveness of density measurements, which, coupled with µOCT's feature of not requiring direct contact, shows promise for future clinical application. The nerve density quantification may be relevant for screening for systemic disease (e.g., peripheral neuropathy). Translational Relevance Technological advances in OCT technology may enable a quick assessment of corneal nerve density, which could be valuable evaluating ophthalmic and systemic peripheral innervation.
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Affiliation(s)
- Merle S Schenk
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Andreas Wartak
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Dermatology, Harvard Medical School, Harvard University, Boston, MA, USA
| | - Verena Buehler
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Institute of Biomedical Optics, University of Luebeck, Luebeck, Germany
| | - Jie Zhao
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
| | - Guillermo J Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Reginald Birngruber
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Institute of Biomedical Optics, University of Luebeck, Luebeck, Germany
| | - Stefan Kassumeh
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany
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Chachar S, Chen J, Qin Y, Wu X, Yu H, Zhou Q, Fan X, Wang C, Brownell I, Xiao Y. Reciprocal signals between nerve and epithelium: how do neurons talk with epithelial cells? AMERICAN JOURNAL OF STEM CELLS 2021; 10:56-67. [PMID: 34849302 PMCID: PMC8610808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Most epithelium tissues continuously undergo self-renewal through proliferation and differentiation of epithelial stem cells (known as homeostasis), within a specialized stem cell niche. In highly innervated epithelium, peripheral nerves compose perineural niche and support stem cell homeostasis by releasing a variety of neurotransmitters, hormones, and growth factors and supplying trophic factors to the stem cells. Emerging evidence has shown that both sensory and motor nerves can regulate the fate of epithelial stem cells, thus influencing epithelium homeostasis. Understanding the mechanism of crosstalk between epithelial stem cells and neurons will reveal the important role of the perineural niche in physiological and pathological conditions. Herein, we review recent discoveries of the perineural niche in epithelium mainly in tissue homeostasis, with a limited touch in wound repair and pathogenesis.
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Affiliation(s)
- Sadaruddin Chachar
- Central Lab of Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
- Department of Biotechnology, Faculty of Crop Production, Sindh Agriculture UniversityTandojam 70060, Pakistan
| | - Jing Chen
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang UniversityHangzhou 310016, Zhejiang, China
- Zhejiang University-University of Edinburgh Institute, International Campus, Zhejiang UniversityHaining 314400, Zhejiang, China
| | - Yumei Qin
- School of Food Science and Bioengineering, Zhejiang Gongshang UniversityHangzhou 310018, Zhejiang, China
| | - Xia Wu
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
| | - Haiyan Yu
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
| | - Qiang Zhou
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
| | - Xiaojiao Fan
- School of Pharmacy, Jiangsu UniversityZhenjiang, Jiangsu, China
| | - Chaochen Wang
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang UniversityHangzhou 310016, Zhejiang, China
- Zhejiang University-University of Edinburgh Institute, International Campus, Zhejiang UniversityHaining 314400, Zhejiang, China
| | - Isaac Brownell
- Dermatology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of HealthBethesda 20892, Maryland, USA
| | - Ying Xiao
- Central Lab of Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
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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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Pham TL, Kakazu AH, He J, Nshimiyimana R, Petasis NA, Jun B, Bazan NG, Bazan HEP. Elucidating the structure and functions of Resolvin D6 isomers on nerve regeneration with a distinctive trigeminal transcriptome. FASEB J 2021; 35:e21775. [PMID: 34245621 PMCID: PMC8362171 DOI: 10.1096/fj.202100686r] [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: 04/23/2021] [Revised: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 12/26/2022]
Abstract
Innervation sustains cornea integrity. Pigment epithelium‐derived factor (PEDF) plus docosahexaenoic acid (DHA) regenerated damaged nerves by stimulating the synthesis of a new stereoisomer of Resolvin D6 (RvD6si). Here, we resolved the structure of this lipid isolated from mouse tears after injured corneas were treated with PEDF + DHA. RvD6si synthesis was inhibited by fluvoxamine, a cytochrome P450 inhibitor, but not by 15‐ or 5‐LOX inhibitors, suggesting that the 4‐ and 17‐hydroxy of DHA have an RR‐ or SR‐configuration. The two compounds were chemically synthesized. Using chiral phase HPLC, four peaks of RvD6si1‐4 from tears were resolved. The RR‐RvD6 standard eluted as a single peak with RvD61 while pure SR‐RvD6 eluted with RvD63. The addition of these pure mediators prompted a trigeminal ganglion transcriptome response in injured corneas and showed that RR‐RvD6 was the more potent, increasing cornea sensitivity and nerve regeneration. RR‐RvD6 stimulates Rictor and hepatocyte growth factor (hgf) genes specifically as upstream regulators and a gene network involved in axon growth and suppression of neuropathic pain, indicating a novel function of this lipid mediator to maintain cornea integrity and homeostasis after injury.
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Affiliation(s)
- Thang L Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Azucena H Kakazu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Robert Nshimiyimana
- Department of Chemistry and Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, CA, USA
| | - Nicos A Petasis
- Department of Chemistry and Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, CA, USA
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
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Lasagni Vitar RM, Rama P, Ferrari G. The two-faced effects of nerves and neuropeptides in corneal diseases. Prog Retin Eye Res 2021; 86:100974. [PMID: 34098111 DOI: 10.1016/j.preteyeres.2021.100974] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 12/16/2022]
Abstract
Corneal nerves are instrumental to maintain cornea integrity through regulation of key physiological functions such as tear secretion, blink reflex, and neuropeptide turnover. Corneal nerve injury/stimulation can follow many insults including mechanical/chemical trauma, infections and surgeries. Nerve disruption initiates a process named neurogenic inflammation which leads to edema, pain, and recruitment and activation of leukocytes. Interestingly, leukocyte influx in the cornea can further damage nerves by releasing inflammatory mediators-including neuropeptides. The clinical outcome of neuroinflammation can be beneficial or detrimental to corneal integrity. On one side, it ensures prompt wound healing and prevents infections. On the other, prolonged and/or deranged neuroinflammation can permanently disrupt corneal integrity and impair vision. The cornea is an ideal site to study peripheral neuroinflammation and neurogenic inflammation since it receives the highest density of sensory nerves of the entire body. We will review the corneal nerve anatomy and neurochemistry, discuss the beneficial and detrimental effects of neurogenic inflammation in corneal wound healing, inflammatory processes, and pain. We will also examine the emerging remote impact of corneal nerve disruption on the trigeminal ganglion and the brain, highlighting the key role of neuropeptide Substance P. Finally, we will discuss the clinical relevance of such neuroinflammatory network in the context of severe and highly prevalent ocular diseases, including potential treatments.
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Affiliation(s)
- Romina Mayra Lasagni Vitar
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Rama
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giulio Ferrari
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Milan, Italy.
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Abstract
The review provides basic information about embryology, structural features, biochemical composition, functions and classification of corneal nerve fibers, and describes anatomical, histological and functional diagnostic techniques for corneal nerves. Each method for analyzing the structure of the nerve fiber, its advantages and disadvantages are described in detail, including the history of the development of confocal microscopy (laser and light) and esthesiometry (contact and non-contact). The article also presents the criteria according to which the structure of the nerve fiber is estimated using laser confocal microscopy, and the shortcomings of these criteria. Additionally, the article reports on the futility of the use of modern esthesiometry methods.
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Affiliation(s)
- Z V Surnina
- Research Institute of Eye Diseases, Moscow, Russia
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30
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Temporal evolution of the biological response to laser-induced refractive index change (LIRIC) in rabbit corneas. Exp Eye Res 2021; 207:108579. [PMID: 33864783 DOI: 10.1016/j.exer.2021.108579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/22/2021] [Accepted: 04/10/2021] [Indexed: 02/06/2023]
Abstract
Laser-induced refractive index change (LIRIC) is a new, non-incisional, non-ablative, femtosecond photo-modification technique being developed for vision correction in humans. Prior, exvivo studies showed intra-tissue refractive index change to induce minimal cell death, restricted to the laser focal zone in the corneal stroma, and with no observable damage to the epithelium or endothelium. Here, we used live rabbits to ascertain longer-term consequences of LIRIC in vivo. Specifically, we assessed cell death, fibrosis, corneal nerve distribution, endothelial cell density, and corneal structure for up to 3 months after LIRIC. A +2.5 D gradient-index LIRIC Fresnel lens was inscribed inside 20 applanated corneas of Dutch Belted rabbits, over a circular region of the mid-stroma measuring 4.5 mm in diameter. Twelve additional rabbit eyes were used as applanation-only controls to differentiate the effects of laser treatment and suction applanation on biological and structural parameters. In vivo optical measurements were performed pre-operatively, then immediately, 2, 4, and 12 weeks after the procedure, to measure endothelial cell density and changes in corneal structure. Groups of four rabbits were sacrificed at 4 hours, 2, 4, and 12 weeks after LIRIC for histological determinations; the TUNEL assay was used to evaluate cell death, H&E staining was used to assess inflammatory infiltration, and immunostaining for α-smooth muscle actin (α-SMA) and βIII tubulin (Tuj-1) was performed to assess myofibroblast differentiation and corneal nerve distribution, respectively. Consistent with prior ex vivo data, only minimal cell death was observed in the laser focal zone, with TUNEL-positive cells restricted to the stromal region of refractive index change 4 h after LIRIC. No TUNEL-positive cells were evident anywhere in the cornea 2, 4, or 12 weeks after LIRIC. Applanation-only corneas were completely TUNEL-negative. Neither LIRIC-treated nor applanation-only eyes exhibited α-SMA-positive staining or altered corneal nerve distributions at any of the time points examined. In vivo confocal imaging revealed normal endothelial cell densities in all eyes (whether LIRIC-treated or applanation-only) at all time points. Optical coherence tomography showed suction applanation to cause a temporary decrease in central corneal thickness, which returned to normal within 4 h. Corneas into which LIRIC Fresnel lenses were written while applanated did not undergo major structural or shape changes beyond the temporary thinning already described for suction applanation. The present findings suggest that LIRIC patterns, which generated a clinically-relevant refractive correction in the mid-stromal region of live rabbit corneas, induced little-to-no disruption to corneal structure and biology for 3 months after the procedure. This affirms the relative safety of LIRIC and predicts that compared to traditional laser vision correction surgeries, common post-operative complications such as dry eye, haze, or patient discomfort may be entirely avoided.
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Mirzajan A, Khezri F, Jafarzadehpur E, Karimian F, Khabazkhoob M. Normal corneal sensitivity and its changes with age in Tehran, Iran. Clin Exp Optom 2021; 98:54-7. [DOI: 10.1111/cxo.12214] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 05/19/2014] [Accepted: 06/21/2014] [Indexed: 11/28/2022] Open
Affiliation(s)
- Ali Mirzajan
- Optometry Department, Iran University of Medical Sciences, Tehran, Iran,
| | - Fatemeh Khezri
- Optometry Department, Iran University of Medical Sciences, Tehran, Iran,
| | | | - Farid Karimian
- Ophthalmology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran,
| | - Mahdi Khabazkhoob
- Department of Epidemiology, Faculty of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran,
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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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33
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Overview of Neurotrophic Keratopathy and a Stage-Based Approach to Its Management. Eye Contact Lens 2021; 47:140-143. [PMID: 33208601 DOI: 10.1097/icl.0000000000000760] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2020] [Indexed: 11/26/2022]
Abstract
ABSTRACT Neurotrophic keratopathy (NK) occurs because of disruption of corneal sensory innervation. There are many etiologies that can lead to NK, such as infection, trauma, topical medication use, cornea surgery, and intracranial tumors among others. We review the current available treatment options and provide a stage-based approach to its management.
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34
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Pham TL, Bazan HEP. Docosanoid signaling modulates corneal nerve regeneration: effect on tear secretion, wound healing, and neuropathic pain. J Lipid Res 2021; 62:100033. [PMID: 32788291 PMCID: PMC7933495 DOI: 10.1194/jlr.tr120000954] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/31/2020] [Indexed: 12/30/2022] Open
Abstract
The cornea is densely innervated, mainly by sensory nerves of the ophthalmic branch of the trigeminal ganglia (TG). These nerves are important to maintain corneal homeostasis, and nerve damage can lead to a decrease in wound healing, an increase in corneal ulceration and dry eye disease (DED), and neuropathic pain. Pathologies, such as diabetes, aging, viral and bacterial infection, as well as prolonged use of contact lenses and surgeries to correct vision can produce nerve damage. There are no effective therapies to alleviate DED (a multifunctional disease) and several clinical trials using ω-3 supplementation show unclear and sometimes negative results. Using animal models of corneal nerve damage, we show that treating corneas with pigment epithelium-derived factor plus DHA increases nerve regeneration, wound healing, and tear secretion. The mechanism involves the activation of a calcium-independent phospholipase A2 that releases the incorporated DHA from phospholipids and enhances the synthesis of the docosanoids, neuroprotectin D1 (NPD1) and a new resolvin stereoisomer, resolvin D6i (RvD6i). NPD1 stimulates the synthesis of brain-derived neurotrophic factor, nerve growth factor, and semaphorin 7A. RvD6i treatment of injured corneas modulates gene expression in the TG resulting in enhanced neurogenesis, decreased neuropathic pain, and increased sensitivity. Taken together, these results represent a promising therapeutic option to reestablish the homeostasis of the cornea.
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Affiliation(s)
- Thang L Pham
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA.
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35
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He J, Pham TL, Bazan HEP. Neuroanatomy and neurochemistry of rat cornea: Changes with age. Ocul Surf 2020; 20:86-94. [PMID: 33340717 DOI: 10.1016/j.jtos.2020.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE To characterize the entire rat corneal nerve architecture, the changes that occur with aging, and its sensory, sympathetic, and parasympathetic fiber distribution. METHODS Sprague-Dawley rats (aged 1 day to 2 years old) of both sexes were euthanized, and the whole corneas were immunostained with protein gene product 9.5 (PGP9.5). The specimens were double-labeled with antibodies against calcitonin gene-related peptide (CGRP) and substance P (SP) as sensory nerve markers, vasoactive intestinal peptide (VIP) as a parasympathetic nerve marker, and neuropeptide Y (NPY) and tyrosine hydroxylase (TH) as markers of sympathetic fibers. Relative nerve density positive for each antibody was assessed by computer-assisted image analysis. RESULTS Thick nerve trunks enter the cornea in the middle of the stroma and run towards the anterior stroma, subsequently dividing into smaller branches that penetrate upwards into the epithelium to form the subbasal nerve bundles. There was no significant difference in corneal innervation between sexes. CGRP and SP were the major sensory neuropeptides with 47.6% ± 3.5% and 34.9% ± 5.1%, respectively, of the total nerves. VIP was 18.4% ± 5.7%, and NPY and TH positive fibers took up 6.92% ± 2.66% and 2.92% ± 1.52%, respectively. Epithelial nerve density increased with age, reached full development at 5 weeks, and decreased at 120 weeks. CONCLUSION This study provides a complete nerve architecture and content of components of sensory, parasympathetic, and sympathetic nerves in the rat cornea. The normal innervation pattern described here will provide an essential baseline for investigators who use the rat model for assessing corneal pathologies that involve nerve alterations.
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Affiliation(s)
- Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA; Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Thang Luong Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA; Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, USA.
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Wartak A, Schenk MS, Bühler V, Kassumeh SA, Birngruber R, Tearney GJ. Micro-optical coherence tomography for high-resolution morphologic imaging of cellular and nerval corneal micro-structures. BIOMEDICAL OPTICS EXPRESS 2020; 11:5920-5933. [PMID: 33149996 PMCID: PMC7587290 DOI: 10.1364/boe.402971] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/31/2020] [Accepted: 09/13/2020] [Indexed: 05/15/2023]
Abstract
We demonstrate the highest resolution (1.5×1.5×1 µm) micrometer optical coherence tomography (µOCT) imaging of the morphologic micro-structure of excised swine and non-human primate corneas. Besides epithelial, stromal, and endothelial cell morphology, this report focuses on investigating the most peripheral corneal nerve fibers, the nerve fibers of the subbasal plexus (SBP). Alterations of SBP nerve density and composition are reportedly linked to major neurologic disorders, such as diabetic neuropathy, potentially indicating earliest onsets of denervation. Here, the fine, hyperreflective, epithelial nerve structures located just above Bowman's membrane, are i) visualized using our µOCT prototype, ii) validated by comparison to fluorescence confocal microscopy (including selective immunohistochemical staining), and iii) segmented using state-of-the-art image processing. Here, we also introduce polarization sensitive (PS) µOCT imaging, demonstrating, to the best of our knowledge, the highest resolution corneal PS-OCT scans reported to date.
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Affiliation(s)
- Andreas Wartak
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Dermatology, Harvard Medical School, Harvard University, Boston, MA 02115, USA
- co-first authors
| | - Merle S. Schenk
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Ophthalmology, University Hospital, LMU Munich, Munich 80336, Germany
- co-first authors
| | - Verena Bühler
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Institute of Biomedical Optics, University of Lübeck, Lübeck 23562, Germany
| | - Stefan A. Kassumeh
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Ophthalmology, University Hospital, LMU Munich, Munich 80336, Germany
| | - Reginald Birngruber
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Institute of Biomedical Optics, University of Lübeck, Lübeck 23562, Germany
- co-senior authors
| | - Guillermo J. Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA
- co-senior authors
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Medeiros CS, Santhiago MR. Corneal nerves anatomy, function, injury and regeneration. Exp Eye Res 2020; 200:108243. [PMID: 32926895 DOI: 10.1016/j.exer.2020.108243] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 09/06/2020] [Accepted: 09/08/2020] [Indexed: 12/29/2022]
Abstract
The cornea is a highly innervated tissue, exhibiting a complex nerve architecture, distribution, and structural organization. Significant contributions over the years have allowed us to come to the current understanding about the corneal nerves. Mechanical or chemical trauma, infections, surgical wounds, ocular or systemic comorbidities, can induce corneal neuroplastic changes. Consequently, a cascade of events involving the corneal wound healing, trophic functions, neural circuits, and the lacrimal products may interfere in the corneal homeostasis. Nerve physiology drew the attention of investigators due to the popularization of modern laser refractive surgery and the perception of the destructive potential of the excimer laser to the corneal nerve population. Nerve fiber loss can lead to symptoms that may impact the patient's quality of life, and impair the best-corrected vision, leading to patient and physician dissatisfaction. Therefore, there is a need to better understand preoperative signs of corneal nerve dysfunction, the postoperative mechanisms of nerve degeneration and recovery, aiming to achieve the most efficient way of treating nerve disorders related to diseases and refractive surgery.
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Affiliation(s)
| | - Marcony R Santhiago
- University of São Paulo, São Paulo, SP, Brazil; University of Southern California, Los Angeles, CA, United States
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Priyadarsini S, Whelchel A, Nicholas S, Sharif R, Riaz K, Karamichos D. Diabetic keratopathy: Insights and challenges. Surv Ophthalmol 2020; 65:513-529. [PMID: 32092364 PMCID: PMC8116932 DOI: 10.1016/j.survophthal.2020.02.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 12/11/2022]
Abstract
Ocular complications from diabetes mellitus are common. Diabetic keratopathy, the most frequent clinical condition affecting the human cornea, is a potentially sight-threatening condition caused mostly by epithelial disturbances that are of clinical and research attention because of their severity. Diabetic keratopathy exhibits several clinical manifestations, including persistent corneal epithelial erosion, superficial punctate keratopathy, delayed epithelial regeneration, and decreased corneal sensitivity, that may lead to compromised visual acuity or permanent vision loss. The limited amount of clinical studies makes it difficult to fully understand the pathobiology of diabetic keratopathy. Effective therapeutic approaches are elusive. We summarize the clinical manifestations of diabetic keratopathy and discuss available treatments and up-to-date research studies in an attempt to provide a thorough overview of the disorder.
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Affiliation(s)
- S Priyadarsini
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - A Whelchel
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - S Nicholas
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - R Sharif
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - K Riaz
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - D Karamichos
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
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Chin JY, Yang LWY, Ji AJS, Nubile M, Mastropasqua L, Allen JC, Mehta JS, Liu YC. Validation of the Use of Automated and Manual Quantitative Analysis of Corneal Nerve Plexus Following Refractive Surgery. Diagnostics (Basel) 2020; 10:E493. [PMID: 32708510 PMCID: PMC7400400 DOI: 10.3390/diagnostics10070493] [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: 06/12/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 11/16/2022] Open
Abstract
Following refractive surgery, the cornea is denervated and re-innervated, hence a reproducible tool to objectively quantify this change is warranted. This study aimed to determine the repeatability and reproducibility of corneal nerve quantification between automated (ACCMetrics) and manual software (CCMetrics) following refractive surgery. A total of 1007 in vivo confocal microscopy images from 20 post-small incision lenticule extraction (SMILE) or post-laser-assisted in situ keratomileusis (LASIK) patients were evaluated by two independent observers using CCMetrics for corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fibre length (CNFL). Intra-observer and inter-observer reproducibility and repeatability, as well as agreement and correlation between the measurements obtained by ACCMetrics and CCMetrics, were assessed. We found that CNFL demonstrated the best intra- and inter-observer agreement followed by CNFD (intra-class correlation coefficient (ICC) = 0.799 and 0.740, respectively for CNFL; 0.757 and 0.728 for CNFD). CNBD demonstrated poorest intra- and inter-observer ICC. There was an underestimation in ACCMetrics measurements compared to CCMetrics measurements, although the differences were not significant. Our data suggested that both automated and manual methods can be used as reliable tools for the evaluation of corneal nerve status following refractive surgery. However, the measurements obtained with different methods are not interchangeable.
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Affiliation(s)
- Jia Ying Chin
- Singapore Eye Research Institute, Singapore 168751, Singapore; (J.Y.C.); (L.W.Y.Y.); (A.J.S.J.); (J.S.M.)
- School of Medicine, Trinity College Dublin, D02 PN40 Dublin, Ireland
| | - Lily Wei Yun Yang
- Singapore Eye Research Institute, Singapore 168751, Singapore; (J.Y.C.); (L.W.Y.Y.); (A.J.S.J.); (J.S.M.)
| | - Angel Jung Se Ji
- Singapore Eye Research Institute, Singapore 168751, Singapore; (J.Y.C.); (L.W.Y.Y.); (A.J.S.J.); (J.S.M.)
| | - Mario Nubile
- Ophthalmic Clinic, University “G d’Annunzio” of Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy; (M.N.); (L.M.)
| | - Leonardo Mastropasqua
- Ophthalmic Clinic, University “G d’Annunzio” of Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy; (M.N.); (L.M.)
| | - John Carson Allen
- Department of Biostatistics, Duke-NUS Medical School, Singapore 169857, Singapore;
| | - Jodhbir S. Mehta
- Singapore Eye Research Institute, Singapore 168751, Singapore; (J.Y.C.); (L.W.Y.Y.); (A.J.S.J.); (J.S.M.)
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore 168751, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Yu-Chi Liu
- Singapore Eye Research Institute, Singapore 168751, Singapore; (J.Y.C.); (L.W.Y.Y.); (A.J.S.J.); (J.S.M.)
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore 168751, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
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Badian RA, Utheim TP, Lagali N. Region of interest and directional analysis of subbasal nerves in wide-area corneal nerve plexus mosaics in type 2 diabetes mellitus. Sci Rep 2020; 10:10802. [PMID: 32612112 PMCID: PMC7329902 DOI: 10.1038/s41598-020-67737-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/10/2020] [Indexed: 12/30/2022] Open
Abstract
In vivo confocal microscopy (IVCM) imaging of the corneal subbasal nerve plexus (SBNP) is a clinical imaging modality gaining popularity for the diagnosis and follow-up of corneal neuropathy in various conditions such as diabetes mellitus. There remain, however, major limitations to the method, hindering its widespread clinical use. Finding the same exact area of the central cornea to standardize image acquisition is difficult without a reference point. Alternatively, creating wide-area mosaics of the SBNP is resource-intensive and has not yet been developed for routine clinical use. Here, we investigated whether IVCM analysis of the corneal SBNP in a predetermined, anatomically standardized region of interest (ROI) could be applied as an equivalent substitution for wide-area SBNP mosaic generation and analysis. Furthermore, we investigated nerve patterns outside the central corneal region for a possible relationship to type 2 diabetes mellitus status using a publicly available dataset. We found that corneal nerve fibre length density (CNFL) based on the ROI underestimated the mosaic-based CNFL by an average of 34% in 90% of cases (150 eyes), and did not exhibit a significant reduction with diabetes, as seen in the full SBNP. Outside the central cornea, nerve orientation differed depending on the anatomic region (left, central or right superior plexus, P < 0.001). Moreover, in long-term type 2 diabetes mellitus (≥ 10 years, 28 subjects), nerve density in the left superior sector of the SBNP was decreased (P < 0.001) while that in the central superior SBNP increased (P = 0.01) relative to 35 age-matched healthy subjects with normal glucose tolerance. These results indicate that subbasal nerve degeneration in type 2 diabetes mellitus can vary according to anatomic location, and regions with potential diagnostic value outside the central SBNP may warrant further investigation.
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Affiliation(s)
- Reza A Badian
- Unit of Regenerative Medicine, Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.
| | - 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 Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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Pham TL, Kakazu AH, He J, Jun B, Bazan NG, Bazan HEP. Novel RvD6 stereoisomer induces corneal nerve regeneration and wound healing post-injury by modulating trigeminal transcriptomic signature. Sci Rep 2020; 10:4582. [PMID: 32165657 PMCID: PMC7067818 DOI: 10.1038/s41598-020-61390-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/24/2020] [Indexed: 01/20/2023] Open
Abstract
The high-density corneal innervation plays a pivotal role in sustaining the integrity of the ocular surface. We have previously demonstrated that pigment epithelium-derived factor (PEDF) plus docosahexaenoic acid (DHA) promotes corneal nerve regeneration; here, we report the mechanism involved and the discovery of a stereospecific Resolvin D6-isomer (RvD6si) that drives the process. RvD6si promotes corneal wound healing and functional recovery by restoring corneal innervation after injury. RvD6si applied to the eye surface elicits a specific transcriptome signature in the trigeminal ganglion (TG) that includes Rictor, the rapamycin-insensitive complex-2 of mTOR (mTORC2), and genes involved in axon growth, whereas genes related to neuropathic pain are decreased. As a result, attenuation of ocular neuropathic pain and dry eye will take place. Thus, RvD6si opens up new therapeutic avenues for pathologies that affect corneal innervation.
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Affiliation(s)
- Thang L Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Azucena H Kakazu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA.
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Zhao K, Yu H, Zheng X, Yang J, Wang X, Han Y, Jia L, Zhao J. Use of the Inferior Whorl for Detecting Age-Related Changes in Human Corneal Subbasal Nerve Plexus with Laser Scanning Confocal Microscopy. Ophthalmic Res 2020; 64:769-774. [PMID: 32135545 DOI: 10.1159/000506952] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/02/2020] [Indexed: 11/19/2022]
Abstract
PURPOSE The purpose of this study was to determine the effect of aging on the corneal subbasal nerve plexus (SNP) by employing a wide-field mapping technique of composite images, scanned at the location of a distinctive spiraled subbasal nerve pattern located 1-2 mm inferior to the corneal apex (the inferior whorl) for SNP structural quantification. MATERIALS AND METHODS Central corneal tactile sensitivity (CCTS) and inferior whorl length (IWL) were compared among individuals in 3 age-groups (20-39 years, 40-59 years, and 60-79 years). Statistical analyses constituted the Kruskal-Wallis test, one-way analysis of variance (with the post hoc least significant difference test), Spearman correlation coefficient, and linear regression analysis. RESULTS CCTS remained stable until the age of 50 years, when it began to decrease; the mean CCTS was 58.15 ± 2.46 mm in the group aged 20-39 years, 55.74 ± 3.85 mm in the group aged 40-59 years, and 50.23 ± 3.27 mm in the group aged 60-79 years. IWL decreased with increasing age, with a corresponding linear decline of 0.2088 mm/mm2 per year, and the mean IWL was 25.43 ± 4.50 mm/mm2 in the group aged 20-39 years, 22.71 ± 6.19 mm/mm2 in the group aged 40-59 years, and 18.60 ± 4.21 mm/mm2 in the group aged 60-79 years. CONCLUSION Our work provided a more accurate and repeatable method for corneal nerve analysis using laser scanning confocal microscopy. By using this technique, we confirmed that aging is associated with progressive reduction in subbasal nerve length.
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Affiliation(s)
- Kuiqing Zhao
- Department of Ophthalmology, Yan'an University Affiliated Hospital, Yan'an, China
| | - Hua Yu
- Shanxi Eye Hospital, Taiyuan, China
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Avetisov SE, Surnina ZV, Novikov IA, Chernenkova NA, Tyurina AA. [The effect of the tear film on the results of a direct assessment of the sensitivity of the cornea]. Vestn Oftalmol 2020; 136:81-85. [PMID: 32366074 DOI: 10.17116/oftalma202013602181] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
UNLABELLED Attempts to find clinical application for esthesiometry are associated with studying sensitivity disorders that occur in various diseases (diabetes mellitus, keratitis of various etiologies, corneal erosion, dry eye syndrome), as well as after surgical interventions. PURPOSE To evaluate the influence of the tear film on the results of direct assessment of corneal sensitivity. MATERIAL AND METHODS The study was conducted in a group of 20 healthy volunteers. Criteria for inclusion in the group: absence of any ocular and general systemic diseases in the anamnesis, normal indicators of tear production and stability of the tear film according to Schirmer and Norn tests. The process of testing involved a specially designed device that was used to exert a dosed force by jets of air on the frontal corneal surface and the pressure was recorded at the moment of tactile sensations and at the breakup time of tear film, as an indicator of its biomechanical stability. RESULTS A strong correlation have been found between the pressure of the air stream at the moment of getting tactile sensations and at the breakup of the tear film (R=0.91, p=0.0094). The obtained data indicate that the biomechanical resistance of the lacrimal film is a significant factor preventing the correct assessment of the results of direct corneal esthesiometry in the range of values close to conditionally normal sensitivity. CONCLUSION In this regard, in their current technical implementation, modern esthesiometers can only be used for monitoring (not for diagnosis!) of pathological processes by analyzing relative (compared to each other) - rather than absolute - sensitivity measures (optimally in combination with analysis of the structural changes in the corneal nerves based on laser confocal microscopy).
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Affiliation(s)
- S E Avetisov
- Research Institute of Eye Diseases, Moscow, Russia
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Department of Ophthalmology-2 Trubetskaya St., Moscow, Russia
| | - Z V Surnina
- Research Institute of Eye Diseases, Moscow, Russia
| | - I A Novikov
- Research Institute of Eye Diseases, Moscow, Russia
| | | | - A A Tyurina
- Research Institute of Eye Diseases, Moscow, Russia
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He J, Pham TL, Kakazu AH, Bazan HEP. Remodeling of Substance P Sensory Nerves and Transient Receptor Potential Melastatin 8 (TRPM8) Cold Receptors After Corneal Experimental Surgery. Invest Ophthalmol Vis Sci 2019; 60:2449-2460. [PMID: 31157834 PMCID: PMC6545819 DOI: 10.1167/iovs.18-26384] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose To investigate changes in corneal nerves positive to substance P (SP) and transient receptor potential melastatin 8 (TRPM8) and gene expression in the trigeminal ganglia (TG) following corneal surgery to unveil peripheral nerve mechanism of induced dry eye-like pain (DELP). Methods Surgery was performed on mice by removing the central epithelial and anterior stromal nerves. Mice were euthanized at different times up to 15 weeks. Immunostaining was performed with TRPM8, SP, or protein gene product 9.5 (PGP9.5) antibodies, and epithelial nerve densities were calculated. The origin of TRPM8- and SP-TG neurons were analyzed by retrograde tracing. Gene expression in TG was studied by real-time PCR analysis. Results SP-positive epithelial corneal nerves were more abundant than TRPM8 and were expressed in different TG neurons. After injury, epithelial nerve regeneration occurs in two distinct stages. An early regeneration of the remaining epithelial bundles reached the highest density on day 3 and then rapidly degraded. From day 5, the epithelial nerves originated from the underlying stromal nerves were still lower than normal levels by week 15. The SP- and TRPM8-positive nerve fibers followed the same pattern as the total nerves. TRPM8-positive terminals increased slowly and reached only half of normal values by 3 months. Corneal sensitivity gradually increased and reached normal values on day 12. Corneal injury also induced significant changes in TG gene expression, decreasing trpm8 and tac1 genes. Conclusions Abnormal SP expression, low amounts of TRPM8 terminals, and hypersensitive nerve response occur long after the injury and changes in gene expression in the TG suggest a contribution to the pathogenesis of corneal surgery-induced DELP.
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Affiliation(s)
- Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States.,Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Thang Luong Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Azucena H Kakazu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States.,Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
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Marfurt C, Anokwute MC, Fetcko K, Mahony-Perez E, Farooq H, Ross E, Baumanis MM, Weinberg RL, McCarron ME, Mankowski JL. Comparative Anatomy of the Mammalian Corneal Subbasal Nerve Plexus. Invest Ophthalmol Vis Sci 2019; 60:4972-4984. [PMID: 31790560 PMCID: PMC6886725 DOI: 10.1167/iovs.19-28519] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 10/24/2019] [Indexed: 12/20/2022] Open
Abstract
Purpose The subbasal nerve plexus (SNP) is the densest and most recognizable component of the mammalian corneal innervation; however, the anatomical configuration of the SNP in most animal models remains incompletely described. The purpose of the current study is to describe in detail the SNP architecture in eight different mammals, including several popular animal models used in cornea research. Methods Corneal nerves in mouse, rat, guinea pig, rabbit, dog, macaque, domestic pig, and cow eyes were stained immunohistochemically with antiserum directed against neurotubulin. SNP architecture was documented by digital photomicrography and large-scale reconstructions, that is, corneal nerve maps, using a drawing tube attached to a light microscope. Results Subbasal nerve fibers (SNFs) in mice, rats, guinea pigs, dogs, and macaques radiated centrally from the corneoscleral limbus toward the corneal apex in a whorl-like or spiraling pattern. SNFs in rabbit and bovine corneas swept horizontally across the ocular surface in a temporal-to-nasal direction and converged on the inferonasal limbus without forming a spiral. SNFs in the pig cornea radiated centrifugally in all directions, like a starburst, from a focal point located equidistant between the corneal apex and the superior pole. Conclusions The results of the present study have demonstrated for the first time substantial interspecies differences in the architectural organization of the mammalian SNP. The physiological significance of these different patterns and the mechanisms that regulate SNP pattern formation in the mammalian cornea remain incompletely understood and warrant additional investigation.
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Affiliation(s)
- Carl Marfurt
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Miracle C. Anokwute
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Kaleigh Fetcko
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Erin Mahony-Perez
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Hassan Farooq
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Emily Ross
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Maraya M. Baumanis
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Rachel L. Weinberg
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Megan E. McCarron
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Joseph L. Mankowski
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
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Gamidov GA, Mushkova IA, Kostenev SV, Gamidov AA. [SMILE keratorefractive surgery technique]. Vestn Oftalmol 2019; 135:99-106. [PMID: 31714520 DOI: 10.17116/oftalma201913505199] [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: 11/18/2022]
Abstract
Small incision lenticule extraction (SMILE) keratorefractive surgery technique is a laser surgery alternative to common methods that doesn't require laser ablation of the cornea. Despite its novelty, SMILE technique has already demonstrated positive clinical results comparable to Photorefractive Keratectomy (PRK) and Laser-Assisted in Situ Keratomileusis (LASIK), which led to its widespread application in clinical practice. Compared with other keratorefractive techniques, SMILE has a number of distinct advantage including high biomechanical stability of the cornea, low risk of dry eye syndrome, absence of a corneal flap and associated complications, preservation of corneal epithelium. The article describes the most common SMILE modifications, its weak points and possible complications, as well as methods of additional correction of remaining ametropy.
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Affiliation(s)
- G A Gamidov
- S.N. Fyodorov National Medical Research Center 'MNTK 'Eye Microsurgery', 59A Beskudnikovsky Blvd., Moscow, Russian Federation, 127486
| | - I A Mushkova
- S.N. Fyodorov National Medical Research Center 'MNTK 'Eye Microsurgery', 59A Beskudnikovsky Blvd., Moscow, Russian Federation, 127486
| | - S V Kostenev
- S.N. Fyodorov National Medical Research Center 'MNTK 'Eye Microsurgery', 59A Beskudnikovsky Blvd., Moscow, Russian Federation, 127486
| | - A A Gamidov
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
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Ertan E, Duman R, Duman R. Comparison of pain during intravitreal dexamethasone, ranibizumab and aflibercept injection. Clin Exp Optom 2019; 103:630-633. [PMID: 31691370 DOI: 10.1111/cxo.12974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/08/2019] [Accepted: 08/02/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND This study aimed to compare pain scores of patients during intravitreal aflibercept, ranibizumab or dexamethasone implant injection procedures. METHODS This study included 162 eyes of 162 patients, who received intravitreal ranibizumab, aflibercept or dexamethasone implant injections at our clinic. Following the injection, patients were asked to rate their pain from 0 (no pain) to 10 (worst pain) using a visual analogue pain score survey (VAS). VAS was evaluated according to age, sex, indication for the injection, number of previous intravitreal injections, and lens status in the study eye. RESULTS The mean VAS in the ranibizumab, aflibercept or dexamethasone implant groups was 3.38 ± 2.31, 3.82 ± 2.46, and 3.61 ± 2.94, respectively. Female patients reported a higher average pain score than male patients (p = 0.02). Also, phakic patients reported a higher average pain score than pseudophakic patients (p = 0.01). Pain did not significantly correlate with indication for the injection, number of injections, and injection drugs (p > 0.05). CONCLUSION Pain associated with intravitreal injection is generally mild and associated with sex, age, and lens status. There was no significant difference in pain between intravitreal injections of dexamethasone implant, ranibizumab or aflibercept.
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Affiliation(s)
- Elif Ertan
- Department of Ophthalmology, Siirt Kurtalan State Hospital, Siirt, Turkey
| | - Rahmi Duman
- Department of Ophthalmology, Liv Hospital, Ankara, Turkey
| | - Reşat Duman
- Department of Ophthalmology, School of Medicine, Afyon Kocatepe University, Afyonkarahisar, Turkey
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48
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Corneal nerves in health and disease. Prog Retin Eye Res 2019; 73:100762. [DOI: 10.1016/j.preteyeres.2019.05.003] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 04/25/2019] [Accepted: 05/01/2019] [Indexed: 12/15/2022]
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Taurone S, Miglietta S, Spoletini M, Feher J, Artico M, Papa V, Matassa R, Familiari G, Gobbi P, Micera A. Age related changes seen in human cornea in formalin fixed sections and on biomicroscopy in living subjects: A comparison. Clin Anat 2019; 33:245-256. [PMID: 31595552 PMCID: PMC7027767 DOI: 10.1002/ca.23488] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/21/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022]
Abstract
The purpose of our experimental research was to assess the effects of aging on the main corneal structures in healthy corneas. Small, human cornea samples were collected from 20 Caucasian subjects during surgery for traumatic lesions to the eye. Ten subjects were adults (mean age 28 years) and 10 were elderly (mean age 76 years). Morphological analysis was carried out using light microscopy and electron microscopy. Another 40 patients (20 young: mean age < 30 years; 20 elderly: mean age > 70 years) were studied in vivo by confocal microscopy. The resulting images were analyzed qualitatively, quantitatively, and statistically. The basic light microscope revealed a decrease in endothelial cell density with age accompanied by an increase in endothelial cell size. Transmission electron microscopy revealed a corneal thinning and a decrease in the number of corneal stromal cells. A marked decrease in stromal nerve fibers was observed in the older subjects compared to the younger ones. Variable pressure scanning electron microscopy (VP‐SEM) was used to make surface morphological observations and to determine the chemical composition of in vivo hydrated human corneas. Our results showed the effects of aging on normal corneal morphology highlighting the structural diversity of the corneal layers and revealing an age‐related reduction in nerve fibers, thus explaining the decreased corneal sensitivity that may be observed in the elderly. Clin. Anat. 33:245–256, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Selenia Miglietta
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, "Sapienza" University of Rome, Rome, Italy
| | | | - Janos Feher
- Division of Ophthalmology, University of Pecs, Pecs, Hungary
| | - Marco Artico
- Department of Sensory Organs, "Sapienza" University of Rome, Rome, Italy
| | - Veronica Papa
- Department of Motor Sciences and Wellness, University of Naples "Partenope", Naples, Italy
| | - Roberto Matassa
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, "Sapienza" University of Rome, Rome, Italy
| | - Giuseppe Familiari
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, "Sapienza" University of Rome, Rome, Italy
| | - Pietro Gobbi
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
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Abstract
The cornea is a transparent outermost structure of the eye anterior segment comprising the highest density of innervated tissue. In the process of corneal innervation, trigeminal ganglion originated corneal nerves diligently traverse different corneal cell types in different corneal layers including the corneal stroma and epithelium. While crossing the stromal and epithelial cell layers during innervation, due to the existing physical contacts, close interactions occur between stromal keratocytes, epithelial cells, resident immune cells and corneal nerves. Furthermore, by producing various trophic and growth factors corneal cells assist in maintaining the growth and function of corneal nerves. Similarly, corneal nerve generated growth factors critically modify the corneal cell function in all the corneal layers. Due to their close association and contacts, on-going cross-communication between these cell types and corneal nerves play a vital role in the modulation of corneal nerve function, regeneration during wound healing. The present review highlights the influence of different corneal cell types and growth factors released from these cells on corneal nerve regeneration and function.
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Affiliation(s)
- Bhavani S Kowtharapu
- Department of Ophthalmology, Rostock University Medical Centre, Rostock, Germany
| | - Oliver Stachs
- Department of Ophthalmology, Rostock University Medical Centre, Rostock, Germany
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