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Barhaiya RK, Kumar P. Histology, histochemistry and ultrastructure of cornea of domestic pigs (Sus scrofa domesticus). Anat Histol Embryol 2024; 53:e13068. [PMID: 38837763 DOI: 10.1111/ahe.13068] [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: 10/10/2023] [Revised: 05/21/2024] [Accepted: 05/27/2024] [Indexed: 06/07/2024]
Abstract
A comprehensive light and ultrastructural examination of the cornea in Domestic Pigs (Sus scrofa domesticus) revealed four distinct layers: the anterior epithelium, corneal stroma, Descemet's membrane and endothelium. Although Bowman's layer was not distinctly identified through histology, histochemical analysis indicated the presence of a rudimentary Bowman's layer, possibly vestigial from evolution. Scanning electron microscopy of the outer corneal surface unveiled two cell types, characterized by micro-projections, with light cells exhibiting shorter, thicker projections compared to dark cells. Examination of the inner surface via scanning electron microscopy demonstrated an endothelial layer devoid of cilia and microvilli, yet faint round to oval elevations were observed, potentially representing cell nuclei. Transmission electron microscopy unveiled that basal cells of the anterior epithelium closely adhered to the basement membrane, featuring half desmosomes along the basal surface. These basal cells extensively interconnected through interdigitations and a few desmosomes. The superficial cell layer consisted of a few rows of closely attached flat cells, forming a leak-proof layer with zona occludens. The outermost cells of this layer displayed fine projections to enhance the surface area, facilitating tear film distribution. At lower magnification, Transmission electron microscopy of the corneal stroma revealed alternating light and dark bands, with light bands representing transverse sections of collagen fibril lamellae and dark bands corresponding to longitudinal or oblique sections. Spindle-shaped keratocytes (fibroblasts) were identified as the primary stromal cells, intermingled between the lamellae, and featured long processes in close contact with neighbouring keratocytes. Overall, the histomorphology of the pig cornea resembles that of the human cornea except indistinct Bowman's membrane. This detailed understanding of the normal corneal structure in pigs hold great significance for biomedical research, providing a valuable reference for studies involving this animal model.
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Affiliation(s)
- Rakesh Kumar Barhaiya
- Department of Veterinary Anatomy, College of Veterinary Science and Animal Husbandry, Nanaji Deshmukh Veterinary Science University, Jabalpur, India
| | - Pawan Kumar
- Department of Veterinary Anatomy, College of Veterinary Science, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, India
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Trujillo Cubillo L, Gurdal M, Zeugolis DI. Corneal fibrosis: From in vitro models to current and upcoming drug and gene medicines. Adv Drug Deliv Rev 2024; 209:115317. [PMID: 38642593 DOI: 10.1016/j.addr.2024.115317] [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: 03/06/2023] [Revised: 02/29/2024] [Accepted: 04/18/2024] [Indexed: 04/22/2024]
Abstract
Fibrotic diseases are characterised by myofibroblast differentiation, uncontrolled pathological extracellular matrix accumulation, tissue contraction, scar formation and, ultimately tissue / organ dysfunction. The cornea, the transparent tissue located on the anterior chamber of the eye, is extremely susceptible to fibrotic diseases, which cause loss of corneal transparency and are often associated with blindness. Although topical corticosteroids and antimetabolites are extensively used in the management of corneal fibrosis, they are associated with glaucoma, cataract formation, corneoscleral melting and infection, imposing the need of far more effective therapies. Herein, we summarise and discuss shortfalls and recent advances in in vitro models (e.g. transforming growth factor-β (TGF-β) / ascorbic acid / interleukin (IL) induced) and drug (e.g. TGF-β inhibitors, epigenetic modulators) and gene (e.g. gene editing, gene silencing) therapeutic strategies in the corneal fibrosis context. Emerging therapeutical agents (e.g. neutralising antibodies, ligand traps, receptor kinase inhibitors, antisense oligonucleotides) that have shown promise in clinical setting but have not yet assessed in corneal fibrosis context are also discussed.
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Affiliation(s)
- Laura Trujillo Cubillo
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular & Biomedical Research and School of Mechanical & Materials Engineering, University College Dublin (UCD), Dublin, Ireland
| | - Mehmet Gurdal
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular & Biomedical Research and School of Mechanical & Materials Engineering, University College Dublin (UCD), Dublin, Ireland
| | - Dimitrios I Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular & Biomedical Research and School of Mechanical & Materials Engineering, University College Dublin (UCD), Dublin, Ireland.
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Melnyk S, Bollag WB. Aquaporins in the Cornea. Int J Mol Sci 2024; 25:3748. [PMID: 38612559 PMCID: PMC11011575 DOI: 10.3390/ijms25073748] [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: 02/20/2024] [Revised: 03/18/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024] Open
Abstract
The cornea is an avascular, transparent tissue that allows light to enter the visual system. Accurate vision requires proper maintenance of the cornea's integrity and structure. Due to its exposure to the external environment, the cornea is prone to injury and must undergo proper wound healing to restore vision. Aquaporins (AQPs) are a family of water channels important for passive water transport and, in some family members, the transport of other small molecules; AQPs are expressed in all layers of the cornea. Although their functions as water channels are well established, the direct function of AQPs in the cornea is still being determined and is the focus of this review. AQPs, primarily AQP1, AQP3, and AQP5, have been found to play an important role in maintaining water homeostasis, the corneal structure in relation to proper hydration, and stress responses, as well as wound healing in all layers of the cornea. Due to their many functions in the cornea, the identification of drug targets that modulate the expression of AQPs in the cornea could be beneficial to promote corneal wound healing and restore proper function of this tissue crucial for vision.
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Affiliation(s)
- Samuel Melnyk
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
| | - Wendy B. Bollag
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
- Charlie Norwood Department of Veterans Affairs Medical Center, Augusta, GA 30904, USA
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Klećkowska-Nawrot J, Barszcz K, Stegmann KO, Goździewska-Harłajczuk K. The organ of vision morphology of the southern two-toed sloth (Choloepus didactylus Linnaeus, 1758; Pilosa, Choloepodidae). Anat Histol Embryol 2024; 53:e12984. [PMID: 37822296 DOI: 10.1111/ahe.12984] [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: 12/02/2022] [Revised: 09/07/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023]
Abstract
The Choloepus didactylus is a species belonging to the Choloepodidae family of the Folivora suborder. This study concerns the anatomical, morphometrical, histological and histochemical examination of the eye tunics, eyelids and orbital glands in the three adult Choloepus didactylus coming from the Wroclaw Zoological Garden. The cornea consists of four layers since Bowman's membrane was absent. The presence of palisades of Vogt formed from 14/15 to 20/21 layers of epithelial cells was demonstrated. Macroscopically, the tapetum lucidum was not identified, while degenerative choroidal tapetum lucidum cellulosum was found microscopically. The ciliary muscle was found with our histological approach. The pupil was round in shape (post-mortem). The presence of tarsal glands has not been demonstrated in both eyelids. The conjunctiva-associated lymphoid tissue (CALT) has been shown in the upper and lower eyelids. The superficial gland of the third eyelid produced a seromucous secretion. The third eyelid was shaped like a curved arch and composed of hyaline cartilage. The deep gland of the third eyelid was big and multilobar acinar simple with serous character. The lacrimal gland produced mucous secretion. The results of our research indicate that the features of the eye anatomy in the southern two-toed sloth (C. didactylus) are also typical of the Folivora suborder and have common features and differences with Vermilingua.
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Affiliation(s)
- Joanna Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Karolina Barszcz
- Department of Morphological Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
| | | | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
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Tozetti RAR, de Lima Sousa Araújo R, Moreira MVL, de Souza Akiyama LC, Corrêa JR, Moore BA, Galera PD. Evaluation of the common pauraque (Nyctidromus albicollis) cornea using light and scanning electron microscopy. Anat Histol Embryol 2024; 53:e12987. [PMID: 37850266 DOI: 10.1111/ahe.12987] [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: 05/25/2023] [Revised: 09/26/2023] [Accepted: 10/04/2023] [Indexed: 10/19/2023]
Abstract
The common pauraque Nyctidromus albicollis (Gmelin, 1789) is a widespread avian species; however due to its nocturnal habits and reclusive behaviour, little is known about their vision and ecology. Most avian species are visually dependent with advanced visual systems providing high spatial resolution, on the species needs. Each ocular structure has a specific role in contributing towards high visual function, and the cornea is the first refractive structure in the visual process. However, the common pauraque cornea had not been described until the present data. Therefore, this study aims to describe the morphology and morphometry of the common pauraque cornea by means of light and scanning electron microscopy to evaluate the cross-sectional anatomy as well as the ultrastructure of the endothelial cells. Histological similarities with the cornea of other birds have been observed, but the thickness of the common pauraque cornea is much smaller than the other described corneas. A better understanding of the common pauraque cornea can help us better explain the physiology of vision and the visual requirements of this species. In turn, this will help us better understand how this species successfully interacts with its environment, and will improve our knowledge on how to interpret pathological changes in their cornea in a clinical setting.
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Affiliation(s)
- Rafaela Alves Ribon Tozetti
- Comparative Ophthalmology Laboratory, School of Agricultural Sciences and Veterinary Medicine, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Rosélia de Lima Sousa Araújo
- Comparative Ophthalmology Laboratory, School of Agricultural Sciences and Veterinary Medicine, University of Brasília, Brasília, Distrito Federal, Brazil
| | | | - Larissa Cristina de Souza Akiyama
- Comparative Ophthalmology Laboratory, School of Agricultural Sciences and Veterinary Medicine, University of Brasília, Brasília, Distrito Federal, Brazil
| | - José Raimundo Corrêa
- Laboratory of Microscopy and Microanalyses, Institute of Biology, University of Brasilia, Brasília, Distrito Federal, Brazil
| | - Bret A Moore
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - Paula Diniz Galera
- Comparative Ophthalmology Laboratory, School of Agricultural Sciences and Veterinary Medicine, University of Brasília, Brasília, Distrito Federal, Brazil
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Zhang K, Di G, Bai Y, Liu A, Bian W, Chen P. Aquaporin 5 in the eye: Expression, function, and roles in ocular diseases. Exp Eye Res 2023; 233:109557. [PMID: 37380095 DOI: 10.1016/j.exer.2023.109557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 05/26/2023] [Accepted: 06/25/2023] [Indexed: 06/30/2023]
Abstract
As a water channel protein, aquaporin 5 (AQP5) is essential for the maintenance of the normal physiological functions of ocular tissues. This review provides an overview of the expression and function of AQP5 in the eye and discusses their role in related eye diseases. Although AQP5 plays a vital role in ocular functions, such as maintaining corneal and lens transparency, regulating water movement, and maintaining homeostasis, some of its functions in ocular tissues are still unclear. Based on the key role of AQP5 in eye function, this review suggests that in the future, eye diseases may be treated by regulating the expression of aquaporin.
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Affiliation(s)
- Kaier Zhang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Guohu Di
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Ying Bai
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Anxu Liu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Wenhan Bian
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Peng Chen
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China; Clinical Laboratory, Qingdao Central Hospital, The Second Affiliated Hospital of Medical College of Qingdao University, Qingdao, 266042, Shandong Province, China.
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7
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De Hoon I, Boukherroub R, De Smedt SC, Szunerits S, Sauvage F. In Vitro and Ex Vivo Models for Assessing Drug Permeation across the Cornea. Mol Pharm 2023. [PMID: 37314950 DOI: 10.1021/acs.molpharmaceut.3c00195] [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: 06/16/2023]
Abstract
Drug permeation across the cornea remains a major challenge due to its unique and complex anatomy and physiology. Static barriers such as the different layers of the cornea, as well as dynamic aspects such as the constant renewal of the tear film and the presence of the mucin layer together with efflux pumps, all present unique challenges for effective ophthalmic drug delivery. To overcome some of the current ophthalmic drug limitations, the identification and testing of novel drug formulations such as liposomes, nanoemulsions, and nanoparticles began to be considered and widely explored. In the early stages of corneal drug development reliable in vitro and ex vivo alternatives, are required, to be in line with the principles of the 3Rs (Replacement, Reduction, and Refinement), with such methods being in addition faster and more ethical alternatives to in vivo studies. The ocular field remains limited to a handful of predictive models for ophthalmic drug permeation. In vitro cell culture models are increasingly used when it comes to transcorneal permeation studies. Ex vivo models using excised animal tissue such as porcine eyes are the model of choice to study corneal permeation and promising advancements have been reported over the years. Interspecies characteristics must be considered in detail when using such models. This review updates the current knowledge about in vitro and ex vivo corneal permeability models and evaluates their advantages and limitations.
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Affiliation(s)
- Inès De Hoon
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium
| | - Rabah Boukherroub
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France
| | - Stefaan C De Smedt
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium
| | - Sabine Szunerits
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France
| | - Félix Sauvage
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium
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Park SY, Holmqvist K, Niehorster DC, Huber L, Virányi Z. How to improve data quality in dog eye tracking. Behav Res Methods 2023; 55:1513-1536. [PMID: 35680764 PMCID: PMC10250523 DOI: 10.3758/s13428-022-01788-6] [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] [Accepted: 01/02/2022] [Indexed: 11/08/2022]
Abstract
Pupil-corneal reflection (P-CR) eye tracking has gained a prominent role in studying dog visual cognition, despite methodological challenges that often lead to lower-quality data than when recording from humans. In the current study, we investigated if and how the morphology of dogs might interfere with tracking of P-CR systems, and to what extent such interference, possibly in combination with dog-unique eye-movement characteristics, may undermine data quality and affect eye-movement classification when processed through algorithms. For this aim, we have conducted an eye-tracking experiment with dogs and humans, and investigated incidences of tracking interference, compared how they blinked, and examined how differential quality of dog and human data affected the detection and classification of eye-movement events. Our results show that the morphology of dogs' face and eye can interfere with tracking methods of the systems, and dogs blink less often but their blinks are longer. Importantly, the lower quality of dog data lead to larger differences in how two different event detection algorithms classified fixations, indicating that the results of key dependent variables are more susceptible to choice of algorithm in dog than human data. Further, two measures of the Nyström & Holmqvist (Behavior Research Methods, 42(4), 188-204, 2010) algorithm showed that dog fixations are less stable and dog data have more trials with extreme levels of noise. Our findings call for analyses better adjusted to the characteristics of dog eye-tracking data, and our recommendations help future dog eye-tracking studies acquire quality data to enable robust comparisons of visual cognition between dogs and humans.
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Affiliation(s)
- Soon Young Park
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Vienna, Austria.
- Medical University Vienna, Vienna, Austria.
- University of Vienna, Vienna, Austria.
| | - Kenneth Holmqvist
- Institute of Psychology, Nicolaus Copernicus University in Torun, Torun, Poland
- Department of Psychology, Regensburg University, Regensburg, Germany
- Department of Computer Science and Informatics, University of the Free State, Bloemfontein, South Africa
| | - Diederick C Niehorster
- Lund University Humanities Lab and Department of Psychology, Lund University, Lund, Sweden
| | - Ludwig Huber
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Vienna, Austria
- Medical University Vienna, Vienna, Austria
- University of Vienna, Vienna, Austria
| | - Zsófia Virányi
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Vienna, Austria
- Medical University Vienna, Vienna, Austria
- University of Vienna, Vienna, Austria
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Wilson SE. The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There's a Bowman's Layer. Biomolecules 2023; 13:biom13050771. [PMID: 37238641 DOI: 10.3390/biom13050771] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/10/2023] [Accepted: 04/16/2023] [Indexed: 05/28/2023] Open
Abstract
Bowman's layer is an acellular layer in the anterior stroma found in the corneas of humans, most other primates, chickens, and some other species. Many other species, however, including the rabbit, dog, wolf, cat, tiger, and lion, do not have a Bowman's layer. Millions of humans who have had photorefractive keratectomy over the past thirty plus years have had Bowman's layer removed by excimer laser ablation over their central cornea without apparent sequelae. A prior study showed that Bowman's layer does not contribute significantly to mechanical stability within the cornea. Bowman's layer does not have a barrier function, as many cytokines and growth factors, as well as other molecules, such as EBM component perlecan, pass bidirectionally through Bowman's layer in normal corneal functions, and during the response to epithelial scrape injury. We hypothesized that Bowman's layer represents a visible indicator of ongoing cytokine and growth factor-mediated interactions that occur between corneal epithelial cells (and corneal endothelial cells) and stromal keratocytes that maintain the normal corneal tissue organization via negative chemotactic and apoptotic effects of modulators produced by the epithelium on stromal keratocytes. Interleukin-1 alpha, produced constitutively by corneal epithelial cells and endothelial cells, is thought to be one of these cytokines. Bowman's layer is destroyed in corneas with advanced Fuchs' dystrophy or pseudophakic bullous keratopathy when the epithelium becomes edematous and dysfunctional, and fibrovascular tissue commonly develops beneath and/or within the epithelium in these corneas. Bowman's-like layers have been noted to develop surrounding epithelial plugs within the stromal incisions years after radial keratotomy. Although there are species-related differences in corneal wound healing, and even between strains within a species, these differences are not related to the presence or absence of Bowman's layer.
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Affiliation(s)
- Steven E Wilson
- The Cole Eye Institute, I-32, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
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Kose F, Orhan I, Alan A, Cabir A, Beyaz F, Duzler A. A new perspective on the corneo-scleral junction with three types of microscopy techniques. Microsc Res Tech 2023; 86:629-635. [PMID: 36929228 DOI: 10.1002/jemt.24314] [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: 11/02/2022] [Accepted: 03/03/2023] [Indexed: 03/18/2023]
Abstract
The conjunctions of the cornea and sclera in the eyes of donkeys, cattle, dogs, sheep, pigs and rabbits, regardless of gender, were examined in this study. No animals were specifically sacrificed for this investigation. Scanning electron microscopy, light microscopy, and dissecting microscopy were used in this research. In the limbus of all the animals investigated, the cornea and sclera fused in accordance with a pattern. At the corneo-scleral junction, the sclera was situated anteriorly and the cornea posteriorly in the dorsal and ventral sections of the bulbus oculi. In the medial and lateral parts of the eyeball, the cornea and sclera were facing each other and interlaced. Pigmentation and the sulcus scleralis externus could be used to identify the macro-and micro-anatomical boundaries of the limbus. In addition, the cytoplasm of basal epithelial cells shrank, signaling the end of the corneal epithelium and the start of the conjunctival epithelium. The presence of Bowman's membrane in cattle and sheep eyes was definitely determined in histological examinations. Bowman's membrane in these animals came to an end at the limbus, which is where the conjunctival epithelium starts and the corneal epithelium ends. In all areas of the cornea, Bowman's membrane revealed irregular, abrupt thickening and thinning. The corneal epithelium was thick in the vertex and thinner towards the limbus, whereas Descemet's membrane was thin in the center (vertex) and thick in the periphery (near the limbus). In this study, pictures and diagrams were used to illustrate the general anatomical, histological, and morphometric characteristics of the limbus in the species under investigation. The data from our study showed that the limbus region of the bulbus oculi was narrow in the lateral and medial parts and wide in the dorsal and ventral parts. This was confirmed in the studied animals as a general rule. The width value will undoubtedly affect the number of cells covered by the regions. It is conceivable that these cells will play a significant role in the decision of where to perform surgical procedures in order to promote wound healing, giving doctors an advantage. In this circumstances, we think that the limbus should be studied in terms of clinical methods because it has different shapes depending on the species and the position of the bulbus.
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Affiliation(s)
- Fatma Kose
- Department of Veterinary Anatomy, Institute of Health Sciences, Erciyes University, Kayseri, Turkey
| | - Imdat Orhan
- Erciyes Üniversitesi Teknoloji Geliştirme Bölgesi (TEKNOPARK), Kayseri, Turkey
| | - Aydın Alan
- Faculty of Veterinary Medicine, Department of Anatomy, Erciyes University, Kayseri, Turkey
| | - Ahmet Cabir
- Department of Veterinary Histology and Embryology, Institute of Health Sciences, Erciyes University, Kayseri, Turkey
| | - Feyzullah Beyaz
- Faculty of Veterinary Medicine, Department of Histology and Embryology, Erciyes University, Kayseri, Turkey
| | - Ayhan Duzler
- Faculty of Veterinary Medicine, Department of Anatomy, Erciyes University, Kayseri, Turkey
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Bhend ME, Kempuraj D, Sinha NR, Gupta S, Mohan RR. Role of aquaporins in corneal healing post chemical injury. Exp Eye Res 2023; 228:109390. [PMID: 36696947 PMCID: PMC9975064 DOI: 10.1016/j.exer.2023.109390] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 12/31/2022] [Accepted: 01/19/2023] [Indexed: 01/23/2023]
Abstract
Aquaporins (AQPs) are transmembrane water channel proteins that regulate the movement of water through the plasma membrane in various tissues including cornea. The cornea is avascular and has specialized microcirculatory mechanisms for homeostasis. AQPs regulate corneal hydration and transparency for normal vision. Currently, there are 13 known isoforms of AQPs that can be subclassified as orthodox AQPs, aquaglyceroporins (AQGPs), or supraquaporins (SAQPs)/unorthodox AQPs. AQPs are implicated in keratocyte function, inflammation, edema, angiogenesis, microvessel proliferation, and the wound-healing process in the cornea. AQPs play an important role in wound healing by facilitating the movement of corneal stromal keratocytes by squeezing through tight stromal matrix and narrow extracellular spaces to the wound site. Deficiency of AQPs can cause reduced concentration of hepatocyte growth factor (HGF) leading to reduced epithelial proliferation, reduced/impaired keratocyte migration, reduced number of keratocytes in the injury site, delayed and abnormal wound healing process. Dysregulated AQPs cause dysfunction in osmolar homeostasis as well as wound healing mechanisms. The cornea is a transparent avascular tissue that constitutes the anterior aspect of the outer covering of the eye and aids in two-thirds of visual light refraction. Being the outermost layer of the eye, the cornea is prone to injury. Of the 13 AQP isoforms, AQP1 is expressed in the stromal keratocytes and endothelial cells, and AQP3 and AQP5 are expressed in epithelial cells in the human cornea. AQPs can facilitate wound healing through aid in cellular migration, proliferation, migration, extracellular matrix (ECM) remodeling and autophagy mechanism. Corneal wound healing post-chemical injury requires an integrative and coordinated activity of the epithelium, stromal keratocytes, endothelium, ECM, and a battery of cytokines and growth factors to restore corneal transparency. If the chemical injury is mild, the cornea will heal with normal clarity, but severe injuries can lead to partial and/or permanent loss of corneal functions. Currently, the role of AQPs in corneal wound healing is poorly understood in the context of chemical injury. This review discusses the current literature and the role of AQPs in corneal homeostasis, wound repair, and potential therapeutic target for acute and chronic corneal injuries.
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Affiliation(s)
- Madeline E Bhend
- Department of Ophthalmology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; School of Medicine, University of South Carolina, Columbia, SC, USA; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Duraisamy Kempuraj
- Department of Ophthalmology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; Institute for Neuro-Immune Medicine, Dr. Kiran C. Patel College of Osteopathic Medicine, Nova Southeastern University, Ft. Lauderdale, FL, USA
| | - Nishant R Sinha
- Department of Ophthalmology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, USA
| | - Suneel Gupta
- Department of Ophthalmology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, USA
| | - Rajiv R Mohan
- Department of Ophthalmology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, USA; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, USA.
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Comparative Histology of the Cornea and Palisades of Vogt in the Different Wild Ruminants (Bovidae, Camelidae, Cervidae, Giraffidae, Tragulidae). Animals (Basel) 2022; 12:ani12223188. [PMID: 36428415 PMCID: PMC9687073 DOI: 10.3390/ani12223188] [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: 10/14/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
In the study, we data concerning the histological and morphometrical examination of the cornea and palisades of Vogt in the different species of ruminants from the families Bovidae, Camelidae, Cervidae, Giraffidae and Tragulidae, coming from the Warsaw Zoological Garden, the Wroclaw Zoological Garden and the Division of Animal Anatomy. The following ruminant species were investigated: common wildebeest, Kirk's dik-dik, Natal red duiker, scimitar oryx, sitatunga, Philippine spotted deer, Père David's deer, moose, reindeer, reticulated giraffe, okapi, Balabac mouse-deer and alpaca. The cornea of ruminant species such as the common wildebeest, Kirk's dik-dik, Natal red duiker, scimitar oryx, reindeer and Balabac mouse-deer consisted of four layers (not found in the Bowman's layer): the anterior corneal epithelium, the proper substance of the cornea, the posterior limiting membrane (Descemet's membrane) and the posterior corneal epithelium (endothelium). The anterior corneal epithelium was composed of a multilayer keratinizing squamous epithelium, which was characterized in the studied ruminants with a variable number of cell layers but also with a different thickness both in the central epithelium part and in the peripheral part. Moreover, the proper substance of cornea was thinnest in Balabac mouse-deer, Kirk's dik-dik, Natal red duiker, scimitar oryx, Philippine spotted deer, alpaca, reindeer and sitatunga and was thickest in the reticulated giraffe. The thickest Descemet's membrane was observed in the Père David's deer. The corneal limbus is characterized by a large number of pigment cell clusters in Kirk's dik-dik, scimitar oryx, moose, Balabac mouse-deer and alpaca. In the common wildebeest, Père David's deer, moose, reticulated giraffe, okapi and alpaca, the palisades of Vogt were marked in the form of a crypt-like structure. The corneal limbus epithelium in the examined ruminants was characterized by a variable number of cell layers but also a variable number of melanocytes located in different layers of this epithelium. The detailed knowledge of the corneal structure of domestic and wild animals can contribute to the even better development of methods for treating eye diseases in veterinary medicine.
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Ertaş TD, Kahvecioğlu KO, Erdoğan S. Morphological Aspects and Microscopic Analyses of Fibrous Tunic and Uveal Components in Bovine Eye. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 28:1-14. [PMID: 35616072 DOI: 10.1017/s1431927622000812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
This study aimed to reveal the anatomical features of the bovine eye by scanning electron and light microscopic methods. For this purpose, a total of 40 eyes were evaluated. Gross and microscopic characteristics of the cornea, sclera, ciliary body, choroid, iris, and lens were determined. Bowman's and Descemet's membranes of the cornea were quite dense and prominent. Collagen lamellae of the cornea were wavy in the periphery and more parallel to the basal and metachromatic fibroblasts were noted. Three to four ciliary plicae merged to form ciliary processes. The presence of prominent intermediate bands connecting the ciliary plicae was determined. The zonular fibrils merged and attached to the lens in the form of thick zonular bands. A dense corpora nigra was present at the rectangular pupillary border of the iris. Tapetum fibrosum, consisting of polygonal tapetal cells, was in blue-yellow-green color and covered most of the choroid. A complex drainage system consisting of trabecular meshwork, angular aqueous plexus, ciliary sinus, and scleral venous vessels localized in a fairly wide iridocorneal angle was identified. Identifying structural features of the bovine eye is very important and useful for pathological evaluations, understanding species-specific physiological mechanisms and for operative interventions of ruminant species.
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Affiliation(s)
- Tuba Damla Ertaş
- Department of Anatomy, Faculty of Veterinary Medicine, Tekirdağ Namık Kemal University, Tekirdağ, Turkey
| | - Kifayet Oya Kahvecioğlu
- Department of Anatomy, Faculty of Veterinary Medicine, İstanbul-Cerrrahpaşa University, İstanbul, Turkey
| | - Serkan Erdoğan
- Department of Anatomy, Faculty of Veterinary Medicine, Tekirdağ Namık Kemal University, Tekirdağ, Turkey
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Paszta W, Goździewska-Harłajczuk K, Klećkowska-Nawrot J. Morphology and Histology of the Orbital Region and Eye of the Asiatic Black Bear (Ursus thibetanus)—Similarities and Differences within the Caniformia Suborder. Animals (Basel) 2022; 12:ani12070801. [PMID: 35405790 PMCID: PMC8997068 DOI: 10.3390/ani12070801] [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] [Received: 02/17/2022] [Revised: 03/10/2022] [Accepted: 03/16/2022] [Indexed: 11/16/2022] Open
Abstract
In this study, we present first data concerning the morphological observations of the orbital region, eye tunics, upper and lower eyelids, superficial gland of the third eyelid with the third eyelid, and lacrimal gland in captive adult male Asiatic black bear. The following research methods were used in the work: the eyeball morphometry, the orbital region description, macroscopic description, morphometric and histological analysis of the eye tunics and selected the accessory organs of the eye (Fontana–Masson, hematoxylin & eosin (H&E), Methyl-green-pyronin Y (MGP Y), Movat pentachrome, and picro-Mallory trichrome) as well as histochemical examination (PAS, AB pH 1.0, AB pH 2.5, AB pH 2.5/PAS and HDI). The eyeball of the Asiatic black bear was a spherical shape, while the periorbita was funnel/conical-shaped and the eye socket was of the open type. The cornea was absent of the Bowman’s membrane similar to all domestic dogs and some wild dogs. There were palisades of Vogt in the corneal limbus epithelium similar to the Canidae. Degenerative choroidal tapetum lucidum similar to ranch mink (Mustelidae) has been found. The pupil was big and round in shape. The ciliary muscle, dilatator and sphincter muscle were well developed, similar to the pinnipeds. The lens was biconvex round, similar to the Canidae. The retina was composed similarly to the diurnal terrestrial carnivores. In both eyelids were observed very well-developed tarsal glands, ciliary glands and sebaceous glands. The orbital zone in the eyelids was characterized by lymphoid follicles, diffuse lymphocytes and specialized high endothelial venules. In the anterior palpebral margin of the upper eyelid, soft and short eyelashes were observed, while in the lower eyelids they were absent. The third eyelid was T-shaped and composed of the hyaline tissue, and it contained CALT, similar to that in Canidae. The superficial gland of the third eyelid was a multilobar alveolar branched complex with seromucous nature, while the lacrimal gland was also a multilobar acinar branched complex gland, but producing a mucous–serous secretion. The results of our research indicate that the features of the anatomy of the eye and orbital region in Asiatic black bear are also typical of the Ursidae family. Moreover, a detailed analysis of the morphological eye region may be useful in comparative studies and veterinary diagnostics in this bear species.
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Affiliation(s)
- Wojciech Paszta
- Wroclaw Zoological Garden, Wróblewskiego 1/5, 51-618 Wrocław, Poland
- Correspondence: (W.P.); (K.G.-H.)
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska 1, 51-631 Wrocław, Poland;
- Correspondence: (W.P.); (K.G.-H.)
| | - Joanna Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska 1, 51-631 Wrocław, Poland;
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15
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Almubrad T, Mencucci R, Smedowski A, Samivel R, Almutleb E, Alkanaan A, Khan AA, Masmali A, Akhtar S. Ultrastructural study of collagen fibrils, proteoglycans and lamellae of the cornea treated with iontophoresis - UVA cross-linking and hypotonic riboflavin solution. Saudi J Biol Sci 2021; 28:7160-7174. [PMID: 34867019 PMCID: PMC8626267 DOI: 10.1016/j.sjbs.2021.08.019] [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: 03/25/2021] [Revised: 07/31/2021] [Accepted: 08/03/2021] [Indexed: 11/02/2022] Open
Abstract
To investigate the effects of iontophoresis-ultraviolet A (UVA) cross-linking (CXL) with hypotonic riboflavin solution on the ultrastructural changes in the lamellae, collagen fibrils (CFs), and proteoglycans (PGs) in the central and peripheral stroma of the human corneal buttons. The iontophoresis method was used for the trans-epithelial application of hypotonic riboflavin in ex vivo corneal culture for 5 min. The corneas were irradiated using three methods: Group 1 (G1) , a UVA irradiance of 3 mW/cm2 for 30 min; Group 2 (G2) , a UVA irradiance of 10 mW/cm2 for 9 min; Group 3 (G3) , without UVA irradiation. Three untreated corneas were used as controls ( G0 ). After the CXL procedure, the corneas were processed for electron microscopy. The CF diameter and PGs in each sample were analyzed using the iTEM program. The keratocyte organelles and stromal architecture in the peripheral cornea were better preserved than those in the central cornea. In G1 and G2, the mean CF diameter in the peripheral cornea was significantly higher than that in the central cornea. In G3, the CF diameter in the central cornea was significantly larger than that in the peripheral cornea. Furthermore, differences in PG area size were observed between the central and peripheral corneas in all groups. Riboflavin + UVA application at 3 mW/cm2 for 30 min and 10 mW/cm2 for 9 min was a suitable method of CXL; however, 3 mW/cm2 for 30 min improved the organization and size of the collagen fibrils. CXL treatment applied at the periphery was more effective than that applied at the center.
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Affiliation(s)
- Turki Almubrad
- Cornea Research Chair, Department of Optics and Vision Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Rita Mencucci
- Department of Oto-Neuro-Ophthalmology Surgical Sciences, Eye Clinic, University of Florence, Italy
| | - Adrian Smedowski
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland.,Department of Oto-Neuro-Ophthalmology Surgical Sciences, Eye Clinic, University of Florence, Italy
| | - Ramachandran Samivel
- Cornea Research Chair, Department of Optics and Vision Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Essam Almutleb
- Cornea Research Chair, Department of Optics and Vision Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Aljoharah Alkanaan
- Cornea Research Chair, Department of Optics and Vision Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Adnan Ali Khan
- Cornea Research Chair, Department of Optics and Vision Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Ali Masmali
- Cornea Research Chair, Department of Optics and Vision Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Saeed Akhtar
- Cornea Research Chair, Department of Optics and Vision Sciences, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
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16
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Anatomical and morphometric evaluation of the orbit, eye tunics, eyelids and orbital glands of the captive females of the South African painted dog (Lycaon pictus pictus Temminck, 1820) (Caniformia: Canidae). PLoS One 2021; 16:e0249368. [PMID: 33872321 PMCID: PMC8055035 DOI: 10.1371/journal.pone.0249368] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/16/2021] [Indexed: 12/17/2022] Open
Abstract
In this study, we present the first data concerning the anatomical, morphometrical, histological and histochemical study of the orbit, eye tunics, eyelids and orbital glands in South African Painted Dogs (Lycaon pictus pictus). The study was performed using eyeball morphometry, analysis of the bony orbit including its morphometry, macroscopic study, morphometry, histological examination of the eye tunics and chosen accessory organs of the eye and histochemical analysis. The orbit was funnel shaped and was open-type. There was a single ethmoid opening for the ethmoid nerve on the orbital lamina. The pupil was round, while the ciliary body occupied a relatively wide zone. The iris was brown and retina had a pigmented area. The cellular tapetum lucidum was semi-circular and milky and was composed of 14–17 layers of tapetal cells arranged in a bricklike structure. In the lower eyelid, there was a single conjunctival lymph nodule aggregate. One or two additional large conjunctval folds were observed within the posterior surface of the upper eyelids. The superficial gland of the third eyelid had a serous nature. The third eyelid was T-shaped and was composed of hyaline tissue. Two to three conjunctival lymph nodul aggregates were present within the bulbar conjunctiva of the third eyelid. The lacrimal gland produced a sero-mucous secretion. A detailed anatomic analysis of the eye area in the captive South African Painted Dogs females showed the similarities (especially in the histological examination of the eyetunics and orbital glands) as well as the differences between the Painted dog and the other representatives of Canidae. The differences included the shape and size od the orbita with comparison to the domestic dog. Such differences in the orbit measurements are most likely associated with the skull type, which are defined in relation to domestic dogs. The presented results significantly expand the existing knowledge on comparative anatomy in the orbit, eye and chosen accessory organs in wild Canidae.
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17
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Animal model with structural similarity to human corneal collagen fibrillar arrangement. Anat Sci Int 2021; 96:286-293. [PMID: 33392925 DOI: 10.1007/s12565-020-00590-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 11/24/2020] [Indexed: 12/15/2022]
Abstract
Rabbit and porcine corneas have been used in scientific research due to their structural similarity to the human cornea. Currently, there are no studies that have compared corneal collagen fibrillar diameter, interfibrillar distance and interlamellar distance between human and animal models. Ten pairs of porcine, rabbit, and human corneas were used. These were analysed using light and Transmission Electron microscopy. The collagen fibrillar diameter, interfibrillar distance and interlamellar distance were statistically compared between porcine, rabbit and human corneas. The human, porcine and rabbit; mean collagen fibrillar diameters were: 24.52 ± 2.09 nm; 32.87 ± 0.87 nm; and 33.67 ± 1.97 nm. The mean interfibrillar distances were: 46.10 ± 2.44 nm; 53.33 ± 2.24 nm; and 52.87 ± 2.73 nm, respectively. The collagen fibrillar diameter and interfibrillar distance of porcine and rabbit corneas were significantly different (p < 0.001) to the human corneal values but not form each other. The interlamellar distance of human, porcine and rabbit corneas was: 2190 ± 820 nm; 6460 ± 1180 nm; and 4410 ± 1330 nm, respectively. All the comparisons were statistically different, in porcine versus rabbit at the p < 0.01 level and both porcine and rabbit versus human at the p < 0.001 level. Histologically, all five layers (epithelium, Bowman's layer, stroma, Descemet membrane and endothelium) of the cornea were visible in all the three species. While neither animal model was structurally identical to the human cornea, they are both relatively close to being used as models to study the biomechanical effects of external insults/treatments to be extrapolated to the human cornea.
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18
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THE EYE OF CRAB-EATING FOX ( CERDOCYON THOUS): ANATOMICAL CHARACTERISTICS AND NORMATIVE VALUES OF SELECTED DIAGNOSTIC TESTS, MORPHOMETRY OF CORNEAL TISSUE, AND ARRANGEMENTS OF CORNEAL STROMAL COLLAGEN FIBERS. J Zoo Wildl Med 2020; 51:280-289. [PMID: 32549556 DOI: 10.1638/2018-0129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2019] [Indexed: 11/21/2022] Open
Abstract
This study aimed to evaluate the ophthalmic parameters, morphometric features of corneal tissue, and arrangements of corneal stromal collagen fibers in crab-eating fox (Cerdocyon thous), a species of neotropical wild canid. We conducted the study on six juvenile crab-eating foxes (12 eyes), whilst 16 eyes were obtained post mortem from eight adult crab-eating foxes. The research was divided into two stages. In the first stage, eye anatomical characteristics, tear production (Schirmer 1 tear test, STT1), intraocular pressure (IOP), ocular echobiometry, and specular microscopy parameters related to morphology of corneal endothelium were studied in juvenile animals. In the second stage, morphometric features of corneal tissue (central corneal thickness [CCT] and corneal epithelium thickness) and arrangements of stromal collagen fibers were studied using eyes from adult animals. The main findings were that crab-eating fox eyes have vertical-slit pupils, holangiotic retina, and reference values (mean ± SD) of 13.37 ± 3.79 mm/min for STT1 and of 10.43 ± 3.84 mmHg for IOP. The ocular echobiometric features observed in crab-eating foxes are different from those reported for domestic dogs (Canis familiaris). Conversely, the corneal endothelial parameters are similar to those of domestic dogs. The CCT measured by tissue morphometry was 0.54 ± 0.06 mm, and the corneal epithelium thickness was 60.13 ± 8.71 µm. Mean coherency related to alignment of collagen fibers was 0.66 ± 0.12. The crab-eating fox cornea had predominantly thick collagen fibers. Crab-eating fox eyes have morphofunctional peculiarities. They resemble the eyes of domestic dogs in some aspects, but diverge in others.
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19
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Sebbag L, Mochel JP. An eye on the dog as the scientist's best friend for translational research in ophthalmology: Focus on the ocular surface. Med Res Rev 2020; 40:2566-2604. [PMID: 32735080 DOI: 10.1002/med.21716] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/01/2020] [Accepted: 07/15/2020] [Indexed: 12/15/2022]
Abstract
Preclinical animal studies provide valuable opportunities to better understand human diseases and contribute to major advances in medicine. This review provides a comprehensive overview of ocular parameters in humans and selected animals, with a focus on the ocular surface, detailing species differences in ocular surface anatomy, physiology, tear film dynamics and tear film composition. We describe major pitfalls that tremendously limit the translational potential of traditional laboratory animals (i.e., rabbits, mice, and rats) in ophthalmic research, and highlight the benefits of integrating companion dogs with clinical analogues to human diseases into preclinical pharmacology studies. This One Health approach can help accelerate and improve the framework in which ophthalmic research is translated to the human clinic. Studies can be conducted in canine subjects with naturally occurring or noninvasively induced ocular surface disorders (e.g., dry eye disease, conjunctivitis), reviewed herein, and tear fluid can be easily retrieved from canine eyes for various bioanalytical purposes. In this review, we discuss common tear collection methods, including capillary tubes and Schirmer tear strips, and provide guidelines for tear sampling and extraction to improve the reliability of analyte quantification (drugs, proteins, others).
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Affiliation(s)
- Lionel Sebbag
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.,Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Jonathan P Mochel
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
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20
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Wilson SE. Bowman's layer in the cornea- structure and function and regeneration. Exp Eye Res 2020; 195:108033. [PMID: 32339517 DOI: 10.1016/j.exer.2020.108033] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 03/09/2020] [Accepted: 04/07/2020] [Indexed: 12/13/2022]
Abstract
Bowman's layer lies immediately posterior to the epithelial basement membrane (EBM) and anterior to the stroma proper in humans, chickens, quail, zebra fish, deer, giraffe, antelope, California sea lions, guinea pig and several other species. It is not found in dog, wolf, cat, tiger, lions, rabbit, pigs, cows, goats, or horses. Developmental anomalies of Bowman's layer are rare, but acquired damage to Bowman's layer, or even complete destruction, is frequently seen in advanced bullous keratopathy or Fuchs' endothelial dystrophy. No detrimental effects of removal of Bowman's layer over the central 6-7 mm of central cornea have been noted in millions of patients who've had photorefractive keratectomy (PRK). Recent studies have suggested the randomly-oriented collagen fibrils that make up Bowman's layer do not have a significant barrier function in modulating the passage of moderate- to large-sized proteins. It is hypothesized that Bowman's layer develops in the corneas of those species that have one because of cytokine-mediated interactions occurring between corneal epithelial cells and underlying keratocytes, including negative chemotactic and apoptotic effects on the keratocytes by low levels of cytokines such as interleukin-1α that are gradually released as epithelial cells die and slough during their normal development. A "Bowman's like layer" can generate around stromal epithelial plugs after radial keratotomy, and possibly beneath the central corneal epithelial basement membrane many years after PRK.
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Affiliation(s)
- Steven E Wilson
- Cole Eye Institute, I-32, Cleveland Clinic, 9500, Euclid Ave, Cleveland, OH, United States.
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21
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Barachetti L, Giudice C, Cescon M, Mortellaro CM, Ferrari R, Rampazzo A. The effects of soft cryotherapy on conjunctiva and cornea in isolated pig eyes and comparison with standard liquid nitrogen: A pilot ex vivo study. Vet Ophthalmol 2020; 23:544-551. [PMID: 32154991 DOI: 10.1111/vop.12752] [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: 05/25/2019] [Revised: 01/06/2020] [Accepted: 01/23/2020] [Indexed: 12/29/2022]
Abstract
PURPOSE To evaluate the immediate effects on cornea and conjunctiva of a cryosurgical method based on the application of a dimethyl ether, propane and isobutene solution (DMEPI, Histofreezer® ), and of Liquid Nitrogen (LN2 ; Cry-Ac Cryogun® ). METHODS A total of 52 isolated pig eyes were obtained at the slaughterhouse, preserved for less than one hour in Ringer Lactate and divided into four groups. The first group included eyes treated with two applications of DMEPI in the center of the cornea, the second group eyes treated with DMEPI on the third eyelid's conjunctiva, the third group eyes treated with LN2 on the third eyelid's conjunctiva and the fourth group included eyes treated with LN2 on the central cornea. Each cryogen application (0.8 cm area) lasted 40 seconds. Each group included one (untreated) control eye. The eyes were submitted for routine histopathological evaluation. Histological alterations were recorded and scored with a semiquantitative scoring system. RESULTS No tissue alteration was detected on the conjunctiva, in any of the groups. Treated corneas showed mild to moderate cytoplasmic vacuolization of epithelial cells, shrinkage and hypereosinophilia of small groups of basal epithelial cells and stromal cleft formation. CONCLUSIONS Soft cryosurgery caused no severe acute histologically detectable damage to cornea and conjunctiva in isolated pig eyes, and no significant difference was observed when LN2 and DMEPI treatments were compared. Further in vivo studies should be performed in order to verify possible delayed effects and the clinical efficacy of DMEPI cryosurgery in specific corneal and/or conjunctival diseases.
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Affiliation(s)
- Laura Barachetti
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Milan, Italy.,Istituto Veterinario di Novara, Italy
| | - Chiara Giudice
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Milan, Italy
| | | | - Carlo M Mortellaro
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Milan, Italy
| | - Roberta Ferrari
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Milan, Italy
| | - Antonella Rampazzo
- Veterinary Ophthalmology Service Equine Department Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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22
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Crespo-Moral M, García-Posadas L, López-García A, Diebold Y. Histological and immunohistochemical characterization of the porcine ocular surface. PLoS One 2020; 15:e0227732. [PMID: 31929592 PMCID: PMC6957219 DOI: 10.1371/journal.pone.0227732] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 12/27/2019] [Indexed: 12/20/2022] Open
Abstract
The ocular surface of the white domestic pig (Sus scrofa domestica) is used as a helpful model of the human ocular surface; however, a complete histological description has yet to be published. In this work, we studied porcine eyeballs with intact eyelids to describe and characterize the different structures that form the ocular surface, including the cornea and conjunctiva that covers the bulbar sclera, tarsi, and the nictitating membrane. We determined the distribution of goblet cells of different types over the conjunctiva and analyzed the conjunctival-associated lymphoid tissue (CALT). Porcine eyeballs were obtained from a local slaughterhouse, fixed, processed, and embedded in paraffin blocks. Tissue sections (4 μm) were stained with hematoxylin/eosin, Alcian blue/Periodic Acid Schiff, and Giemsa. Slides were also stained with lectins from Arachis hypogaea (PNA) and Helix pomatia (HPA) agglutinins and immunostained with rabbit anti-CD3. We found that the porcine cornea was composed of 6–8 epithelial cell layers, stroma, Descemet’s membrane, and an endothelial monolayer. The total corneal thickness was 1131.0±87.5 μm (mean±standard error of the mean) in the center and increased to 1496.9±138.2 μm at the limbus. The goblet cell density was 71.25±12.29 cells/mm, ranging from the highest density (113.04±37.21 cells/mm) in the lower palpebral conjunctiva to the lowest density (12.69±4.29 cells/mm) in the bulbar conjunctiva. The CALT was distributed in the form of intraepithelial lymphocytes and subepithelial diffuse lymphoid tissue. Lenticular-shaped lymphoid follicles, about 8 per histological section, were also present within the conjunctival areas. In conclusion, we demonstrated that the analyzed porcine ocular structures are similar to those of humans, confirming the potential usefulness of pig eyes to study ocular surface physiology and pathophysiology.
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Affiliation(s)
- Mario Crespo-Moral
- Ocular Surface Group, IOBA - University of Valladolid, Valladolid, Spain
| | | | - Antonio López-García
- Ocular Surface Group, IOBA - University of Valladolid, Valladolid, Spain.,Biomedical Research Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Valladolid, Spain
| | - Yolanda Diebold
- Ocular Surface Group, IOBA - University of Valladolid, Valladolid, Spain.,Biomedical Research Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Valladolid, Spain
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23
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Armour MD, Askew TE, Eghrari AO. Endothelial keratoplasty for corneal endothelial dystrophy in a dog. Vet Ophthalmol 2019; 22:545-551. [PMID: 30972947 DOI: 10.1111/vop.12670] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 03/19/2019] [Accepted: 03/27/2019] [Indexed: 08/09/2023]
Abstract
OBJECTIVE To assess the efficacy of an endothelial keratoplasty procedure at defined intervals to 1 year postoperatively for the treatment of corneal endothelial dystrophy (CED) in a canine patient. PROCEDURE A dog diagnosed with CED with progressive corneal edema underwent an endothelial keratoplasty. The patient was examined pre- and postoperatively with slit lamp biomicroscopy and ultrasonic pachymetry. RESULTS Mean central corneal thickness (CCT) measured with pachymetry was >1400 μm preoperatively and decreased postoperatively to 725 μm. The transplanted donor tissue became transparent 2 weeks postoperatively and incorporated with the recipient cornea. The graft remained transparent throughout the duration of the postoperative period evaluated in this study (2 weeks postoperatively to 1 year). The canine patient was comfortable pre- and postoperatively. CONCLUSIONS Endothelial keratoplasty is a potential therapeutic option for canine cases with progressive corneal thickening due to CED. As this is a single case study, further investigation into the use of endothelial keratoplasty to treat CED is warranted. Moreover, canine patients with CED might serve as a surgical model for human patients with Fuchs' Endothelial Corneal Dystrophy.
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Affiliation(s)
- Micki D Armour
- Armour Veterinary Ophthalmology, Washington, District of Columbia
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Topical Rho-Associated Kinase Inhibitor, Y27632, Accelerates Corneal Endothelial Regeneration in a Canine Cryoinjury Model. Cornea 2019; 38:352-359. [PMID: 30516555 DOI: 10.1097/ico.0000000000001823] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE Corneal endothelial cell regeneration varies by species, with nonhuman primates (NHPs) and rabbits displaying low and high proliferative capacities, respectively. Recent studies report that topical application of rho-associated kinase (ROCK) inhibitors accelerates corneal endothelial wound healing in animal models and human patients with endothelial dysfunction. This study determines the regenerative capacity of canine corneal endothelial cells in vivo and their response to a topical ROCK inhibitor, Y27632, after transcorneal freezing. METHODS Right eyes of 6 beagles underwent transcorneal freezing; 10 mM ROCK inhibitor Y27632 or vehicle control was applied topically to both eyes at least 4 times daily for 56 days. Endothelial cell density was evaluated by in vivo confocal microscopy, and corneal thickness was measured by Fourier-domain optical coherence tomography (FD-OCT) and ultrasound pachymetry. RESULTS Transcorneal freezing induced severe central corneal edema in dogs, with restoration of transparency occurring within 4 weeks. Y27632 significantly decreased corneal thickness by FD-OCT and ultrasound pachymetry in the acute phase and significantly increased endothelial cell density at days 28 and 42 post-cryoinjury, suggesting faster restoration of endothelial cell recovery. CONCLUSIONS Canine corneal endothelial function recovers at a similar rate as NHPs but more slowly than rabbits after cryoinjury. Faster corneal endothelial wound healing was observed by in vivo confocal microscopy and FD-OCT in dogs treated with Y27632 versus vehicle controls. Thus, a canine cryoinjury model may be a useful alternative to NHPs in detecting a response to therapies directed at endothelial regeneration.
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Kammergruber E, Rahn C, Nell B, Gabner S, Egerbacher M. Morphological and immunohistochemical characteristics of the equine corneal epithelium. Vet Ophthalmol 2019; 22:778-790. [PMID: 30767359 PMCID: PMC6900071 DOI: 10.1111/vop.12651] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/18/2019] [Accepted: 01/21/2019] [Indexed: 12/13/2022]
Abstract
Objective The morphology of the corneal epithelium in two age groups of horses is described. Distribution patterns of proliferation‐, differentiation‐, stem cell‐associated markers and cell junction proteins were assessed. Methods Corneal samples from 12 horses (six foals and six adult horses) were analyzed after H&E staining and immunohistochemistry using the following antibodies: E‐cadherin, β‐catenin, Connexin 43 (Cx43), tight junction protein 1 (TJP1), cytokeratin (CK) 14, CK 19, CK 3, CK 10, vimentin, Ki67, p63, nerve growth factor (NGF), ABCG2, and epithelial growth factor receptor. Semiquantitative analysis of crypt, limbal, peripheral, and central zone was performed. Semithin and ultrathin sections were used for ultrastructural evaluation of the epithelium. Results The height of the epithelium varied between age groups and crypts were consistently present. In the peripheral and central epithelium, three types of basal cells resembling a pseudostratified epithelium were characterized. Potential stem cell markers (CK 14, p63, NGF, and ABCG2) were present in all zones with decreasing frequency toward the center. Cornea‐specific differentiation marker CK 3 was not expressed in the most basal cell layer of the limbal epithelium. E‐cadherin, β‐catenin, and Cx43 revealed a similar apico‐lateral signal pattern throughout the entire epithelium; only TJP1 was additionally seen at the basal surface. Conclusions This study presents a systematic semiquantitative evaluation of the equine corneal epithelium, showing the presence of crypts as potential stem cell niche with CK 14, p63, NGF, and ABCG2 as relevant markers for cells with regenerative capacity. The pseudostratified arrangement of the basal layer was a unique finding.
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Affiliation(s)
- Eva Kammergruber
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Carolin Rahn
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Barbara Nell
- Department of Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
| | - Simone Gabner
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Monika Egerbacher
- Histology and Embryology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
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Das S, Liu CH, Singh M, Twa MD, Larin KV. Modified wavelength scanning interferometry for simultaneous tomography and topography of the cornea with Fourier domain optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2018; 9:4443-4458. [PMID: 30615727 PMCID: PMC6157774 DOI: 10.1364/boe.9.004443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/15/2018] [Accepted: 08/16/2018] [Indexed: 05/20/2023]
Abstract
Visual acuity is dependent on corneal shape and size. A minor variation in surface geometry can cause a deformation of corneal geometry, which affects its optical performance. In this work we demonstrate an algorithm for the simultaneous measurement of corneal tomography and topography with a traditional point-scanning Fourier domain optical coherence tomography (FD-OCT) system. A modified wavelength scanning interferometry (mWSI) algorithm enabled topographical evaluation of the surface with nanometer-scale resolution, which is superior to the micrometer-scale resolution of traditional OCT structural imaging. We validated the technique with an optically flat mirror, standard roughness gauges, and atomic force microscopy (AFM). The mirror results show nanometer-scale sensitivity (~3.5 nm), and the mWSI measurements were in good agreement (error ~5%) with the specifications of the roughness comparator and AFM, demonstrating the accuracy of the technique. Following validation, the measurements were made on pig corneas in situ at various artificially controlled intraocular pressures (IOP) and before and after cross-linking (CXL). The results show that the mean surface roughness increased by ~65% after removal of the epithelium in preparation for CXL but did not change as a function of IOP. The demonstrated method could be used for simultaneous measurement of tissue tomography with micrometer-precision and topography with nanometer-precision.
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Affiliation(s)
- Susobhan Das
- Department of Biomedical Engineering, University of Houston, Houston, TX 77004, USA
| | - Chih-Hao Liu
- Department of Biomedical Engineering, University of Houston, Houston, TX 77004, USA
| | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, Houston, TX 77004, USA
| | - Michael D. Twa
- College of Optometry, University of Alabama, Birmingham, AL 35294, USA
- Department of Biomedical Engineering, University of Alabama, Birmingham, AL 35294, USA
| | - Kirill V. Larin
- Department of Biomedical Engineering, University of Houston, Houston, TX 77004, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
- Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk, Russia
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Patruno M, Perazzi A, Martinello T, Gomiero C, Maccatrozzo L, Iacopetti I. Investigations of the corneal epithelium in Veterinary Medicine: State of the art on corneal stem cells found in different mammalian species and their putative application. Res Vet Sci 2018; 118:502-507. [PMID: 29758534 DOI: 10.1016/j.rvsc.2018.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/29/2018] [Accepted: 05/07/2018] [Indexed: 02/08/2023]
Abstract
The existence of progenitor cells that can readily differentiate into a specific cell type is a common cellular strategy for physiological tissue growth and repair mechanisms. In the mammalian cornea, many aspects regarding the nature and location of these cells are still unclear. In the human limbus (peripheral area of the cornea) progenitor cells have been found and characterized but in non-human mammals, the picture is not so clear. In this review, we examine current knowledge about the morphology of limbus and the localization of corneal epithelial stem cells in all species studied so far, comparing data with humans. We have also explored different research directions in the veterinary field in order to discuss the: i) currently used protocols and ii) best range of treatments for ocular pathologies in which corneal stem cells are involved.
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Affiliation(s)
- M Patruno
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020, Legnaro - Agripolis, Padova, Italy.
| | - A Perazzi
- Department of Animal Medicine, Production and Health, University of Padova, Viale dell'Università 16, 35020, Legnaro - Agripolis, Padova, Italy
| | - T Martinello
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020, Legnaro - Agripolis, Padova, Italy
| | - C Gomiero
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020, Legnaro - Agripolis, Padova, Italy
| | - L Maccatrozzo
- Department of Comparative Biomedicine and Food Science, University of Padova, Viale dell'Università 16, 35020, Legnaro - Agripolis, Padova, Italy
| | - I Iacopetti
- Department of Animal Medicine, Production and Health, University of Padova, Viale dell'Università 16, 35020, Legnaro - Agripolis, Padova, Italy
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Klećkowska-Nawrot JE, Goździewska-Harłajczuk K, Darska M, Barszcz K, Janeczek M. Microstructure of the eye tunics, eyelids and ocular glands of the Sulawesi bear cuscus (Ailurops ursinusTemminck, 1824) (Phalangeridae: Marsupialia) based on anatomical, histological and histochemical studies. ACTA ZOOL-STOCKHOLM 2018. [DOI: 10.1111/azo.12251] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Joanna E. Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Marta Darska
- Faculty of Biology and Animal Science; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
| | - Karolina Barszcz
- Department of Morphological Sciences; Faculty of Veterinary Medicine; Warsaw University of Life Sciences; Warsaw Poland
| | - Maciej Janeczek
- Department of Biostructure and Animal Physiology; Faculty of Veterinary Medicine; Wroclaw University of Environmental and Life Sciences; Wroclaw Poland
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Shull OR, Reilly CM, Davis LB, Murphy CJ, Thomasy SM. Phenotypic Characterization of Corneal Endothelial Dystrophy in German Shorthaired and Wirehaired Pointers Using In Vivo Advanced Corneal Imaging and Histopathology. Cornea 2018; 37:88-94. [PMID: 29077583 PMCID: PMC5799001 DOI: 10.1097/ico.0000000000001431] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE To evaluate corneal morphology using ultrasonic pachymetry (USP), Fourier-domain optical coherence tomography (FD-OCT), and in vivo confocal microscopy (IVCM) in 2 related canine breeds-German shorthaired pointers (GSHPs) and German wirehaired pointers (GWHPs)-with and without corneal endothelial dystrophy (CED). This condition is characterized by premature endothelial cell degeneration leading to concomitant corneal edema and is similar to Fuchs endothelial corneal dystrophy. METHODS Corneas of 10 CED-affected (4 GSHP and 6 GWHP) and 19 unaffected, age-matched (15 GSHP and 4 GWHP) dogs were examined using USP, FD-OCT, and IVCM. A 2-sample t test or Mann-Whitney rank-sum test was used to statistically compare parameters between both groups. Data are presented as mean ± SD or median (range). RESULTS Central corneal thickness determined using USP was significantly greater in CED-affected than in unaffected dogs at 1179 (953-1959) and 646 (497-737) μm, respectively (P < 0.001). Central epithelial thickness was found to be significantly decreased in CED-affected versus unaffected dogs at 47 ± 7.1 and 55 ± 7.1 μm, respectively (P = 0.011), using FD-OCT. With IVCM, corneal endothelial density was significantly less (P < 0.001) in 5 dogs with CED versus 19 unaffected controls at 499 ± 315 versus 1805 ± 298 cells/mm, respectively. CED-affected dogs exhibited endothelial pleomorphism and polymegethism, whereas CED-unaffected dogs had regular hexagonal arrangement of cells. CONCLUSIONS GSHPs and GWHPs with CED exhibit marked differences in corneal morphology when compared with age-matched control dogs. These 2 CED-affected breeds represent spontaneous, large animal models for human Fuchs endothelial corneal dystrophy.
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Affiliation(s)
- Olivia R. Shull
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | | | - Lola B. Davis
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
| | - Christopher J. Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA
| | - Sara M. Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA
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Thomasy SM, Cortes DE, Hoehn AL, Calderon AC, Li JY, Murphy CJ. In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy. Invest Ophthalmol Vis Sci 2017; 57:OCT495-503. [PMID: 27454658 PMCID: PMC4968913 DOI: 10.1167/iovs.15-18885] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Boston Terriers (BTs) have a greater prevalence of corneal endothelial dystrophy (CED), in comparison to other canine breeds. Similar to Fuchs' endothelial corneal dystrophy (FECD), this condition is characterized by endothelial cell degeneration with secondary corneal edema. This study assessed corneal morphology using in vivo confocal microscopy (IVCM) and Fourier-domain optical coherence tomography (FD-OCT) in BTs with and without CED. Methods The corneas of 16 BTs with CED and 15 unaffected, age-matched BTs underwent clinical evaluation and were imaged using IVCM and FD-OCT. A two-sample t-test or Mann-Whitney rank sum test were used to statistically compare parameters between groups. Data are presented as mean ± SD or median (range). Results Mean age did not significantly differ between affected and unaffected dogs at 10.0 ± 2.0 and 10.6 ± 2.4 years, respectively (P = 0.437). Females (69%) were overrepresented among the CED-affected dogs. In CED patients, IVCM demonstrated endothelial polymegathism and pleomorphism. Corneal endothelial density was significantly less (P < 0.001) in dogs with CED (1026 ± 260 cells/mm2) versus age-matched controls (2297 ± 372 cells/mm2). Fourier-domain OCT demonstrated a significant increase (P < 0.01) in central corneal and endothelium-Descemet's complex thickness in dogs with CED versus age-matched controls at 1019 (485–1550) or 536 (464–650) μm and 32 (22–56) or 25 (15–34) μm, respectively. Conclusions Corneal endothelial dystrophy in BTs is a bilateral, adult-onset condition that shares many similarities with FECD. Thus, CED could serve as a spontaneous disease model to study the pathogenesis of and develop novel treatments for FECD.
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Affiliation(s)
- Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Dennis E Cortes
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Alyssa L Hoehn
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Allison C Calderon
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States
| | - Jennifer Y Li
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, California, United States
| | - Christopher J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, United States 2Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, California, Uni
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Morphological description of limbal epithelium: searching for stem cells crypts in the dog, cat, pig, cow, sheep and horse. Vet Res Commun 2017; 41:169-173. [DOI: 10.1007/s11259-017-9676-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/12/2017] [Indexed: 12/26/2022]
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