1
|
Kepez Yildiz B, Freitas R, Filippini P, Habroosh F, Said DG, Dua HS, Sahay P. Relationship of posterior peripheral corneal layers and the trabecular meshwork: an immunohistological and anatomical study. Br J Ophthalmol 2024:bjo-2023-324844. [PMID: 38418206 DOI: 10.1136/bjo-2023-324844] [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: 11/06/2023] [Accepted: 12/23/2023] [Indexed: 03/01/2024]
Abstract
BACKGROUND/AIM With the popularity of endothelial keratoplasty (EK) procedures, Descemet membrane (DM) EK and pre-Descemet EK, considerable work has been done on understanding the posterior corneal anatomy. Most of the information available relates to the central cornea. We evaluated the peripheral cornea to explore the immunohistological and anatomical relationship between the pre-Descemet layer (PDL), DM and trabecular meshwork (TM). METHODS Six donor human sclerocorneal discs were studied. PDL, DM and TM were examined by light microscopy, transmission electron microscopy (TEM) and immunohistology. The DM was peeled from the centre to the limit of its peripheral attachment, to reach the transition zone (TZ) between TM and peripheral cornea. Ten-micron sections were stained with antibodies against collagens 1, 2, 3, 4, 5, 6, 12, elastin, myocilin, wnt-1, aquaporin, tenascin C, laminin and integrin alpha 3. RESULTS Collagens 2, 3, 4, laminin and myocilin were predominantly seen in the TZ between TM and peripheral cornea. Wnt-1, integrin alpha 3 and tenascin C were highly concentrated in TM. Collagen 1 was present predominantly in the corneal stroma. On TEM; DM was thinner with a denser banded structure spread throughout its thickness in the periphery compared with the central cornea where it presents as the distinct anterior banded layer. CONCLUSION The TZ between DM, PDL and TM shows a unique histological structure at the periphery. The collagen and elastin fibres of the TM are continuous with the PDL. The structures are firmly attached to each other. These findings provide structural information that is relevant to the preparation of DMEK donor tissue.
Collapse
Affiliation(s)
- Burçin Kepez Yildiz
- Ophthalmology, Ministry of Health Istanbul Beyoglu Eye Training and Research Hospital, Istanbul, Turkey
- Academics Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - Rui Freitas
- Academics Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - Perla Filippini
- Academics Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - Fatima Habroosh
- Academics Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - Dalia G Said
- Academics Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - Harminder Singh Dua
- Academics Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - Prity Sahay
- Academics Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| |
Collapse
|
2
|
Gupta N, Kumar A, Vaddavalli PK, Mahapatra NR, Varshney A, Ghosh P. Efficient reduction of the scrolling of Descemet membrane endothelial keratoplasty grafts by engineering the medium. Acta Biomater 2023; 171:239-248. [PMID: 37739249 DOI: 10.1016/j.actbio.2023.09.024] [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: 05/26/2023] [Revised: 09/08/2023] [Accepted: 09/15/2023] [Indexed: 09/24/2023]
Abstract
The Descemet Membrane Endothelial Keratoplasty (DMEK) procedure for corneal transplantation is challenging due to the need to unscroll the donor graft within the recipient's eye. This process of unscrolling is complex, time-consuming, leads to a loss of endothelial cells and, most importantly, can negatively impact the graft's adhesion and integration with the host tissue after surgery. This problem is particularly evident when the graft is young. However, the physics behind this scrolling is not well understood, and therefore no sustainable solution is attained. Here, we propose that the concentration gradient of the medium used during transplant leads to a displacement gradient across the graft thickness, resulting in an out-of-plane folding or scrolling of the graft tissue. Using chitosan bilayer-based experimental models, it is experimentally demonstrated that this diffusion-coupled-deformation phenomenon can successfully explain why younger donor grafts tend to scroll tighter than older ones. Most importantly, we illustrate here through experiments that the medium can be engineered to reduce the scroll tightness and thus reduce the surgical inconveniences and improve post-transplant recovery. STATEMENT OF SIGNIFICANCE: This paper addresses a major issue that surgeons face while doing Descemet Membrane Endothelial Keratoplasty (DMEK) in unscrolling grafts during the graft insertion procedure. The currently used tapping method to unscroll the graft inside the patient's eye significantly reduces endothelial cell count, thus affecting its lifetime. Surprisingly, the physics behind graft scrolling is not well understood, so no sustainable solutions are proposed by the medical community. In this work, we present the underlying mechanism of DMEK graft scroll and illustrate experimentally the reason for scroll tightness through a chitosan bilayer based experiment model. Most importantly, we have successfully demonstrated that the preserving medium of the grafts can be engineered to reduce scroll tightness.
Collapse
Affiliation(s)
- Nidhi Gupta
- Department of Cornea Dr Shroff's Charity Eye Hospital, Delhi, India
| | - Amit Kumar
- Department of Biotechnology & Department of Applied Mechanics, IIT Madras, India
| | | | | | - Akhil Varshney
- Eicher-Shroff Center for Stem Cell Research, Dr Shroff's Charity Eye Hospital, Daryaganj, Delhi, India.
| | - Pijush Ghosh
- Department of Applied Mechanics and Biomedical Engineering; Center for Soft and Biological Matter, IIT Madras, India.
| |
Collapse
|
3
|
Dua HS, Freitas R, Mohammed I, Ting DSJ, Said DG. The pre-Descemet's layer (Dua's layer, also known as the Dua-Fine layer and the pre-posterior limiting lamina layer): Discovery, characterisation, clinical and surgical applications, and the controversy. Prog Retin Eye Res 2023; 97:101161. [PMID: 36642673 DOI: 10.1016/j.preteyeres.2022.101161] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 12/22/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023]
Abstract
The pre-Descemet's layer/Dua's layer, also termed the Dua-Fine layer and the pre-posterior limiting lamina layer, lies anterior to the Descemet's membrane in the cornea, is 10 μm (range 6-16) thick, made predominantly of type I and some type VI collagen with abundant elastin, more than any other layer of the cornea. It has high tensile strength (bursting pressure up to 700 mm of Hg), is impervious to air and almost acellular. At the periphery it demonstrates fenestrations and ramifies to become the core of the trabecular meshwork, with implications for intraocular pressure and glaucoma. It has been demonstrated in some species of animals. The layer has assumed considerable importance in anterior and posterior lamellar corneal transplant surgery by improving our understanding of the behaviour of corneal tissue during these procedures, improved techniques and made the surgery safer with better outcomes. It has led to the innovation of new surgical procedures namely, pre-Descemet's endothelial keratoplasty, suture management of acute hydrops, DALK-triple and Fogla's mini DALK. The discovery and knowledge of the layer has introduced paradigm shifts in our age old concepts of Descemet's membrane detachment, acute corneal hydrops in keratoconus and Descemetoceles, with impact on management approaches. It has been shown to contribute to the pathology and clinical signs observed in corneal infections and some corneal dystrophies. Early evidence suggests that it may have a role in the pathogenesis of keratoconus in relation to its elastin content. Its contribution to corneal biomechanics and glaucoma are subjects of current investigations.
Collapse
Affiliation(s)
- Harminder S Dua
- Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, The Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK.
| | - Rui Freitas
- Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, The Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK; Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Portugal.
| | - Imran Mohammed
- Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, The Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK.
| | - Darren S J Ting
- Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, The Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK.
| | - Dalia G Said
- Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, The Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK; Research Institute of Ophthalmology, Cairo, Egypt.
| |
Collapse
|
4
|
Dua HS, Freitas R, Sadek Y, Ting DSJ, Nubile M, Mohammed I, Said DG. An approach to reduce Descemet's membrane scrolling: Relevance to Descemet's membrane endothelial keratoplasty (DMEK). Indian J Ophthalmol 2023; 71:3178-3185. [PMID: 37602605 PMCID: PMC10565912 DOI: 10.4103/ijo.ijo_1531_23] [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: 06/11/2023] [Accepted: 07/20/2023] [Indexed: 08/22/2023] Open
Abstract
Purpose We aimed to determine whether Descemet's membrane (DM) scrolling occurs primarily along the vertical or horizontal axis and establish whether oval trephination along the axis of least scrolling can reduce the grade of the scroll. Methods The longest limbus-to-limbus axis on 28 sclerocorneal discs was taken as the horizontal axis. The horizontal (n = 7) or (right angles to it) vertical (n = 6) axis was marked on DM before peeling it off. The direction and grade of scrolling was observed. Narrow strips (3-4 mm wide) were then cut along the two axes (n = 4 each) and the scrolling pattern was observed. Ellipses (7 × 9 mm) of DM were punched along the two axes (n = 6 each) and the scrolls graded. Immunofluorescent staining for elastin on horizontal and vertical tissue sections from three DM samples was performed. The intensity and thickness of elastin staining were measured. Results Twenty-four (85.72%) DM samples showed scrolling along the horizontal axis, none showed scrolling along the vertical axis, and four (14.28%) samples showed a spiral scroll, regardless of which axis was marked (grade 3.7 and 3.6). Vertically oval discs showed significantly reduced scrolling (grade 1.2) compared to horizontally oval discs (grade 3.5). Narrow strips of DM showed a similar scrolling pattern. Immunohistology showed no difference in any of the parameters examined along the two axes or from the center to the periphery. Conclusion DM scrolls primarily along the horizontal axis. Vertically oval DM samples show minimal scrolling, which can be an advantage in DMEK. Differential scrolling is not determined by the distribution of elastin.
Collapse
Affiliation(s)
- Harminder S Dua
- Department of Ophthalmology, Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, and the Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK
| | - Rui Freitas
- Department of Ophthalmology, Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, and the Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK
- Department of Ophthalmology, Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Portugal
| | - Youssef Sadek
- Department of Medicine, University of Birmingham, Birmingham Research Park, Birmingham, UK
| | - Darren SJ Ting
- Department of Ophthalmology, Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, and the Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK
| | - Mario Nubile
- Department of Medicine and Aging Science, Ophthalmology Clinic, University G. d’Annunzio of Chieti-Pescara, Italy
| | - Imran Mohammed
- Department of Ophthalmology, Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, and the Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK
| | - Dalia G Said
- Department of Ophthalmology, Larry A Donoso Laboratory for Eye Research, Academic Unit of Ophthalmology and Visual Sciences, University of Nottingham, and the Queens Medical Centre, Nottingham University Hospitals, NHS Trust, Nottingham, England, UK
| |
Collapse
|
5
|
Kafarnik C, Faraj LA, Ting DSJ, Goh JN, Said DG, Dua HS. Ex vivo demonstration of canine corneal pre-Descemet's anatomy using pneumodissection as for the big bubble technique for deep anterior lamellar keratoplasty. Sci Rep 2023; 13:5922. [PMID: 37041151 PMCID: PMC10090133 DOI: 10.1038/s41598-022-24438-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 11/15/2022] [Indexed: 04/13/2023] Open
Abstract
The recent discovery and characterization of pre-Descemet's layer (PDL; also termed the Dua's layer or the Dua-Fine layer) has advanced the understanding of various posterior corneal pathologies and surgeries in human. This study aimed to characterize the ultrastructure of the posterior stroma and interfacial zone of Descemet's membrane (DM) in canine eyes. Eighteen canine corneo-scleral discs were included. Intrastromal air injection resulted in the formation of type 1 big bubble (BB) in 73% (n = 11/15) of corneas, with a mean diameter of 11.0 ± 1.3 mm. No type 2 BB was created. Anterior segment optical coherence tomography, histology and transmission electron microscopy confirmed that the wall of BB was composed of DM, in contact with remaining stroma (canine PDL; cPDL). The cPDL was populated with keratocytes, of varying thickness of 16.2 ± 4.2 µm in close apposition to the DM, and composed of collagen bundles arranged in transverse, longitudinal and oblique directions. The interfacial zone, between DM and cPDL, showed fibril extension in all three directions, predominantly longitudinal. Irregular extensions of DM material into cPDL stroma were observed. No long-spaced collagen was detected. In conclusion, there exists a well-defined cleavage plane between the posterior stroma and cPDL, with similar but not identical characteristics as in humans, that is revealed by pneumodissection. This adds to our understanding of the anatomy of the posterior most canine cornea, which will have significant clinical impact on posterior corneal surgery and understanding of corneal pathology in dogs.
Collapse
Affiliation(s)
| | - Lana A Faraj
- Academic Ophthalmology, Eye ENT Centre, School of Medicine, University of Nottingham, B Floor, Nottingham, NG7 2UH, UK
| | - Darren S J Ting
- Academic Ophthalmology, Eye ENT Centre, School of Medicine, University of Nottingham, B Floor, Nottingham, NG7 2UH, UK
- Department of Ophthalmology, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Jia Ni Goh
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - Dalia G Said
- Academic Ophthalmology, Eye ENT Centre, School of Medicine, University of Nottingham, B Floor, Nottingham, NG7 2UH, UK
- Department of Ophthalmology, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Harminder S Dua
- Academic Ophthalmology, Eye ENT Centre, School of Medicine, University of Nottingham, B Floor, Nottingham, NG7 2UH, UK.
- Department of Ophthalmology, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK.
| |
Collapse
|
6
|
Effect of Low-Temperature Preservation in Optisol-GS on Preloaded, Endothelium-Out DMEK Grafts. J Clin Med 2023; 12:jcm12031026. [PMID: 36769674 PMCID: PMC9917566 DOI: 10.3390/jcm12031026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/16/2023] [Accepted: 01/24/2023] [Indexed: 01/31/2023] Open
Abstract
The aim of the study was to assess different temperature ranges for the preservation of pre-loaded Descemet Membrane Endothelial Keratoplasty (DMEK) grafts in the DMEK RAPID Mini device. METHODS Three groups of 15 DMEK grafts (five per group) were pre-loaded in the DMEK RAPID Mini and preserved in Optisol-GS for 72 h at different temperatures: group A at >8 °C, group B between 2-8 °C and group C at <2 °C. After stripping and preservation, the viability of the endothelium, cell loss and morphology were assessed through light microscopy following trypan blue and alizarin red staining. RESULTS Overall mortality was 4.07%, 3.97% and 7.66%, in groups A, B and C, respectively, with percentages of uncovered areas of 0.31%, 1.36% and 0.20% (all p > 0.05). Endothelial cell density variation was 5.51%, 3.06% and 2.82% in groups A, B and C, respectively (p = 0.19). Total Endothelial Cell Loss (ECL) was 4.37%, 5.32% and 7.84% in groups A, B and C, respectively (p = 0.39). Endothelial cell morphology was comparable in all three groups. CONCLUSIONS In the DMEK RAPID Mini, low temperatures (<2 °C) may affect the quality of pre-loaded grafts, inducing a higher ECL after 72 h of preservation, although no significant differences among groups could be proved. Our data would suggest maintaining grafts loaded in the DMEK RAPID Mini at temperatures between 2-8 °C for appropriate preservation.
Collapse
|
7
|
Muijzer MB, Heslinga FG, Couwenberg F, Noordmans HJ, Oahalou A, Pluim JPW, Veta M, Wisse RPL. Automatic evaluation of graft orientation during Descemet membrane endothelial keratoplasty using intraoperative OCT. BIOMEDICAL OPTICS EXPRESS 2022; 13:2683-2694. [PMID: 35774322 PMCID: PMC9203112 DOI: 10.1364/boe.446519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/31/2021] [Accepted: 02/24/2022] [Indexed: 05/27/2023]
Abstract
Correct Descemet Membrane Endothelial Keratoplasty (DMEK) graft orientation is imperative for success of DMEK surgery, but intraoperative evaluation can be challenging. We present a method for automatic evaluation of the graft orientation in intraoperative optical coherence tomography (iOCT), exploiting the natural rolling behavior of the graft. The method encompasses a deep learning model for graft segmentation, post-processing to obtain a smooth line representation, and curvature calculations to determine graft orientation. For an independent test set of 100 iOCT-frames, the automatic method correctly identified graft orientation in 78 frames and obtained an area under the receiver operating characteristic curve (AUC) of 0.84. When we replaced the automatic segmentation with the manual masks, the AUC increased to 0.92, corresponding to an accuracy of 86%. In comparison, two corneal specialists correctly identified graft orientation in 90% and 91% of the iOCT-frames.
Collapse
Affiliation(s)
- Marc B. Muijzer
- Utrecht Cornea Research Group, Ophthalmology Department, University Medical Center Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
- Contributed equally
| | - Friso G. Heslinga
- Department of Biomedical Engineering, Eindhoven University of Technology, Postbus 513, 5600 MB, Eindhoven, The Netherlands
- Contributed equally
| | - Floor Couwenberg
- University of Twente, Drienerlolaan 5, 7522 NB Enschede, The Netherlands
| | - Herke-Jan Noordmans
- Medical technical and Clinical physics department, University Medical Center Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | | | - Josien P. W. Pluim
- Department of Biomedical Engineering, Eindhoven University of Technology, Postbus 513, 5600 MB, Eindhoven, The Netherlands
- Image Sciences Institute, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
| | - Mitko Veta
- Department of Biomedical Engineering, Eindhoven University of Technology, Postbus 513, 5600 MB, Eindhoven, The Netherlands
- Contributed equally
| | - Robert P. L. Wisse
- Utrecht Cornea Research Group, Ophthalmology Department, University Medical Center Utrecht, Heidelberglaan 100, 3584CX, Utrecht, The Netherlands
- Contributed equally
| |
Collapse
|
8
|
Fritz M, Grewing V, Gruber M, Wagner H, Zander D, Lapp T, Lang SJ, Heinzelmann‐Mink S, Maier PC, Reinhard T, Wacker K. Rotational alignment of corneal endothelial grafts and risk of graft detachment after Descemet membrane endothelial keratoplasty: a double-masked pseudo-randomized study. Acta Ophthalmol 2021; 99:e1334-e1339. [PMID: 33742563 DOI: 10.1111/aos.14849] [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: 10/26/2020] [Revised: 02/08/2021] [Accepted: 02/23/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE The posterior cornea is rotationally asymmetric, and Descemet membrane endothelial keratoplasty (DMEK) grafts preferentially scroll vertically. This prospective study assessed whether graft attachment after DMEK differed depending on the rotational alignment of the donor graft in the recipient eye. METHODS Pseudo-randomization and blinding of the graft orientation in the recipient's eye were possible by procedural separation: (1) The eye bank recorded the position of an orientation marker in the donor cornea; (2) the surgeon preparing the DMEK graft recorded an upside-down marker relative to the eye bank marker; and (3) the surgeon assessed the position of the upside-down marker in the recipient after DMEK. Surgeons were masked towards the eye bank marker. Using mixed-effects models, we assessed graft attachment relative to the rotational alignment of the donor graft. RESULTS Postoperatively, the graft was not fully attached in 59 of 179 eyes (33%). A second air fill (rebubbling) was performed in 11%. The graft axis was in line with the recipient cornea axis in 40%, oblique in 28% and orthogonal in 32%. We did not detect an elevated risk of incomplete attachment (odds ratio [OR], 1.16; 95% CI, 0.61-2.20), risk of rebubbling (OR, 1.25; 95% CI, 0.47-3.31) or larger areas of graft detachment in non-aligned grafts compared to aligned grafts. CONCLUSION Rotational alignment was not strongly associated with the risk of incomplete graft attachment, although modestly elevated risks cannot be ruled out. Efforts are needed to reduce the need for rebubbling after DMEK and to identify modifiable risk factors for graft detachment.
Collapse
Affiliation(s)
- Marianne Fritz
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Viviane Grewing
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Markus Gruber
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Helena Wagner
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Daniel Zander
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Thabo Lapp
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Stefan J. Lang
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | | | - Philip C. Maier
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Thomas Reinhard
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| | - Katrin Wacker
- Eye Centre Medical Centre Faculty of Medicine University of Freiburg Freiburg Germany
| |
Collapse
|
9
|
Yeu E, Gomes JAP, Ayres BD, Chan CC, Gupta PK, Beckman KA, Farid M, Holland EJ, Kim T, Starr CE, Mah FS. Posterior lamellar keratoplasty: techniques, outcomes, and recent advances. J Cataract Refract Surg 2021; 47:1345-1359. [PMID: 33769774 DOI: 10.1097/j.jcrs.0000000000000634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/22/2021] [Indexed: 10/21/2022]
Abstract
Over the past 2 decades, posterior lamellar keratoplasty (PLK) has emerged as an alternative to penetrating keratoplasty in the treatment of corneal endothelial disorders. The reasons for this trend include the search for a safer procedure to replace diseased endothelium that provides faster and better visual rehabilitation and reduces the need for postoperative care. Different surgical techniques, surgical instruments, devices, and lasers have been introduced to overcome technical difficulties, thus improving clinical outcomes. Yet, surgeons and eye banks must address the complications and limitations that arise during the transition to these new techniques. This review discusses the most significant aspects of the evolution of PLK, including a detailed description of current techniques and the direction of future treatment for corneal endothelial disease with the use of laser-assisted surgery, bioengineered corneas, cell therapy, and new pharmacologic therapy.
Collapse
Affiliation(s)
- Elizabeth Yeu
- From the Eastern Virginia Medical School and Virgina Eye Consultants, Norfolk, Virginia (Yeu); Department of Ophthalmology, UNIFESP/EPM and Instituto Suel Abujamra, Sao Paulo, Brazil (Gomes); Wills Eye Hospital, Philadelphia, Pennsylvania (Ayres); University of Toronto, Ontario, and the Eye Bank of Canada, Ontario Division, Ontario, Canada (Chan); Duke Eye Center, Durham, North Carolina (Gupta); Comprehensive Eyecare of Central Ohio, Westerville (Beckman); Department of Ophthalmology, Ohio State University, Columbus (Beckman); Gavin Herbert Eye Institute, University of California, Irvine (Farid); Department of Ophthalmology, University of Cincinnati, and Cincinnati Eye Institute, Cincinnati, Ohio (Holland); Duke Eye Center and Duke University School of Medicine, Durham, North Carolina (Kim); Weill Cornell Medicine and New York Presbyterian Hospital, New York, New York (Starr); Scripps Clinic Medical Group, La Jolla, California (Mah)
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Ong HS, Ang M, Mehta J. Evolution of therapies for the corneal endothelium: past, present and future approaches. Br J Ophthalmol 2021; 105:454-467. [PMID: 32709756 PMCID: PMC8005807 DOI: 10.1136/bjophthalmol-2020-316149] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 05/16/2020] [Indexed: 12/13/2022]
Abstract
Corneal endothelial diseases are leading indications for corneal transplantations. With significant advancement in medical science and surgical techniques, corneal transplant surgeries are now increasingly effective at restoring vision in patients with corneal diseases. In the last 15 years, the introduction of endothelial keratoplasty (EK) procedures, where diseased corneal endothelium (CE) are selectively replaced, has significantly transformed the field of corneal transplantation. Compared to traditional penetrating keratoplasty, EK procedures, namely Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK), offer faster visual recovery, lower immunological rejection rates, and improved graft survival. Although these modern techniques can achieve high success, there are fundamental impediments to conventional transplantations. A lack of suitable donor corneas worldwide restricts the number of transplants that can be performed. Other barriers include the need for specialized expertise, high cost, and risks of graft rejection or failure. Research is underway to develop alternative treatments for corneal endothelial diseases, which are less dependent on the availability of allogeneic tissues - regenerative medicine and cell-based therapies. In this review, an overview of past and present transplantation procedures used to treat corneal endothelial diseases are described. Potential novel therapies that may be translated into clinical practice will also be presented.
Collapse
Affiliation(s)
- Hon Shing Ong
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore, Singapore
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore
- Department of Ophthalmology and Visual Science, Duke-National University of Singapore (NUS) Graduate Medical School, Singapore, Singapore
| | - Marcus Ang
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore, Singapore
- Department of Ophthalmology and Visual Science, Duke-National University of Singapore (NUS) Graduate Medical School, Singapore, Singapore
| | - Jodhbir Mehta
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore, Singapore
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore
- Department of Ophthalmology and Visual Science, Duke-National University of Singapore (NUS) Graduate Medical School, Singapore, Singapore
- School of Material Science & Engineering and School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore
| |
Collapse
|
11
|
Perdikakis G, Fili S, Vastardis I, Kohlhaas M. The correct graft orientation during descemet membrane endothelial keratoplasty (DMEK) using the "bubble-tap" technique. Int Ophthalmol 2021; 41:2329-2337. [PMID: 33730315 DOI: 10.1007/s10792-021-01786-1] [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: 11/27/2020] [Accepted: 03/06/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE To demonstrate a novel, alternative endothelium Descemet membrane layer (EDM) orientation method in Descemet membrane endothelial keratoplasty (DMEK) that does not involve prior ink or trepanation marking of the graft, or intraoperative ocular coherence tomography (OCT) guided graft implantation during surgery, thus preventing the occurrence of an upside-down graft implantation that leads with certainty to primary graft failure. METHODS From 2017 to early 2020, 500 eyes underwent DMEK operation using the "bubble-tap" technique first described from Dr. Perdikakis in the department of ophthalmology of St.-Johannes- Hospital in Dortmund in Germany. Primary graft failure and re-bubbling results following "bubble-tap" assisted DMEK are presented. RESULTS Primary graft failure due to upside-down graft implantation was not observed in any patient. Re-bubbling was performed in 4.8% of the eyes. In 1.8% of the cases, a re-DMEK was performed due to a graft failure. CONCLUSION The "bubble-tap" technique is a novel, reliable and easy to master orientation method of EDM that enables the surgeon to perform DMEK with safety even in complicated cases with poor visibility in the anterior chamber, while it yields superior or equal results in comparison to other graft marking methods or intraoperative OCT-guided graft implantation.
Collapse
Affiliation(s)
- Georgios Perdikakis
- Clinic of Ophthalmology, St. Johannes Hospital, Johannesstrasse 9-17, 44137, Dortmund, Germany.
| | - Sofia Fili
- Clinic of Ophthalmology, St. Johannes Hospital, Johannesstrasse 9-17, 44137, Dortmund, Germany
| | | | - Markus Kohlhaas
- Clinic of Ophthalmology, St. Johannes Hospital, Johannesstrasse 9-17, 44137, Dortmund, Germany
| |
Collapse
|
12
|
Pereira NC, Forseto ADS, Maluf RCP, Dua HS. Pre-Descemet's endothelial keratoplasty: a simple, Descemet's membrane scoring technique for successful graft preparation. Br J Ophthalmol 2021; 106:786-789. [PMID: 33597193 DOI: 10.1136/bjophthalmol-2020-317613] [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: 07/29/2020] [Revised: 12/04/2020] [Accepted: 01/12/2021] [Indexed: 12/14/2022]
Abstract
PURPOSE Pre-Descemet's endothelial keratoplasty (PDEK) donor tissue preparation involves the intrastromal injection of air to create a type 1 big bubble (BB) and avoidance of the creation of a type 2 BB. The purpose of this study was to design and test a technique to consistently creates a type 1 BB without risk of creating a type 2 BB. METHODS A prospective matched study with 64 human donor sclerocorneal discs, which were not suitable for corneal transplantation, was conducted. The corneas were divided into two groups, of which 32 were subjected to the standard technique of preparing the PDEK donor tissue (group 1, control) and 32 new technique, where in the donor Descemet's membrane was scored with a Sinskey hook. Frequency of occurrence of different types of BB was compared and statistically analysed. RESULTS With the standard technique (group 1), type 1 BB occurred in 53.1%, type 2 BB in 34.4% and mixed BB in 12.5% of samples. With the scoring technique (group 2), a type 1 BB occurred in 100% of the samples. No type 2 or mixed BB occurred in any case in group 2. The difference in creation of a type 1BB between the two groups was statistically significant (p=0.00). CONCLUSION The scoring technique is a simple, inexpensive and reproducible option to consistently achieve a type 1 BB to prepare PDEK graft tissue. The next step would be to study the clinical outcomes of PDEK performed with tissue obtained by the scoring technique.
Collapse
Affiliation(s)
- Nicolas Cesario Pereira
- Department of Ophthalmology, Sorocaba Eye Hospital, Sorocaba, São Paulo, Brazil .,Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Adriana Dos Santos Forseto
- Department of Ophthalmology, Sorocaba Eye Hospital, Sorocaba, São Paulo, Brazil.,Eye Clinic, São Paulo, São Paulo, Brazil
| | | | - Harminder Singh Dua
- Academic Section of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, Nottinghamshire, UK
| |
Collapse
|
13
|
Goweida MB, Abuelkheir A, El-Menawy WAR, Mahmoud S. Dynamics of Big Bubble Formation During Deep Anterior Lamellar Keratoplasty in Eyes with Advanced Keratoconus. Clin Ophthalmol 2020; 14:4305-4310. [PMID: 33324036 PMCID: PMC7733416 DOI: 10.2147/opth.s277738] [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: 08/20/2020] [Accepted: 11/19/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose To study the dynamics of big bubble (BB) formation in eyes with advanced keratoconus (KC) during deep anterior lamellar keratoplasty (DALK). Methods A retrospective review of medical records and videos of DALK surgeries performed during the period from January 2013 to December 2019 on keratoconic eyes. Eyes with formed BB, in the presence of a relatively clear stroma, were included. We studied the following parameters the location of BB commencement, duration from the start of the bubble until complete formation, and the pattern of air passage during the formation process. Results A total of 37 eyes met the inclusion criteria. Type 1 BB was formed in 22 eyes with a mean formation time of 1.9 ± 1.1 seconds and a mean bubble diameter of 7.6 ± 1.1 mm. Type 1 BB started in the center as a small dome expanding centrifugally with preceding localized stromal whitening in 19 eyes and without whitening in three eyes. Type 2 BB was formed in 14 eyes with a mean formation time of 0.3 ± 0.12 seconds and a mean bubble diameter of 7.4 ± 1.8 mm. Type 2 BB started in the center in 13 eyes and the mid periphery in one eye, through either direct access to the plane between Descemet’s membrane and the pre-Descemet’s layer in six eyes, or preceded by a small intrastromal bubble in eight eyes. Mixed bubble was observed in one eye, which started as a small central Type 1 BB followed by the rapid formation of a Type 2 BB. Conclusion Eyes with KC are associated with central commencements of both Type 1 and Type 2 BB during DALK. Duration of BB formation was significantly faster in Type 2 BB, with most starting as a small intrastromal bubble before air gain access to the plane between DM and stroma.
Collapse
Affiliation(s)
- Mohamed Bahgat Goweida
- Department of Ophthalmology, Alexandria Main, University Hospital, Alexandria, Egypt.,Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Amr Abuelkheir
- Department of Ophthalmology, Alexandria Main, University Hospital, Alexandria, Egypt.,Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Wael Abdel Rahman El-Menawy
- Department of Ophthalmology, Alexandria Main, University Hospital, Alexandria, Egypt.,Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Shahira Mahmoud
- Department of Ophthalmology, Alexandria Main, University Hospital, Alexandria, Egypt.,Faculty of Medicine, Alexandria University, Alexandria, Egypt
| |
Collapse
|
14
|
Vertical Scrolling Axis of Corneal Endothelial Grafts for Descemet Membrane Endothelial Keratoplasty. Cornea 2020; 40:497-501. [PMID: 33298743 DOI: 10.1097/ico.0000000000002583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Heterogeneity in scrolling behavior of Descemet membrane endothelial keratoplasty (DMEK) grafts complicates DMEK surgery. This prospective observational study assessed scrolling axes of DMEK grafts relative to the donor's eye. METHODS The eye bank randomly marked the rim of corneoscleral donor buttons during trephination and recorded the position relative to the donor's axis. Surgeons were masked to the absolute position of the eye bank marking and recorded the scrolling axis relative to the eye bank marking and DMEK upside-down orientation. The scrolling axis was categorized as vertical (0 to 30 degrees and 150 to 180 degrees), oblique (>30 to 60 degrees and 120 to <150 degrees), and horizontal (>60 to <120 degrees). Scrolling patterns of corneas from the same donor were assessed. RESULTS Scrolling patterns of 202 donor corneas from 149 donors were determined. The donor graft scrolled predominantly vertically to the donor's cornea [75%; 95% confidence interval (CI), 68%-80%]. Horizontal axes (11%) and oblique axes (14%) were less common. The median deviation in scrolling axes after unfolding the grafts was 0 degrees from the original scrolling axis (interquartile range, 0-15), indicating that scrolling axes were stable. Fellow eyes of 46 donors had 3.55 times higher odds of a nonvertical scrolling pattern if the first eye had a nonvertical scrolling pattern (95% CI, 1.37-9.20), suggesting that donor factors influencing both eyes could contribute to scrolling patterns. CONCLUSIONS DMEK grafts have a natural and stable scrolling tendency at vertical axis of donor's cornea. Anticipating scrolling axes might help improve preparation techniques for DMEK grafts and outcomes.
Collapse
|
15
|
Gruber M, Reinhard T, Wacker K, Maier PC. Scrolling of the Donor Cornea in Dependence of Temperature and Osmolarity for Descemet Membrane Endothelial Keratoplasty. Klin Monbl Augenheilkd 2020; 239:308-312. [PMID: 33202433 DOI: 10.1055/a-1227-4748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND After preparation of a graft for Descemet membrane endothelial keratoplasty (DMEK), the diameter of the graft's scroll varies significantly. In particular, narrow scrolls may complicate DMEK surgery. In this study we investigated how temperature, osmolarity, and deswelling of the donor tissue influence scrolling diameter. MATERIAL AND METHODS In this study we examined donor corneas that could not be used for transplantation. The diameter of the DMEK donor scrolls was measured after graft preparation by reflected light microscopy under different conditions: (1) The diameter of the roll was measured in Ringer's solution at temperatures of 5 °C, 24 °C and 35 °C. (2) To study the effect of different culture conditions we used 6% dextran-containing medium for 10 min, 20 min, 16 h and 24 h, and hyper- and hypoosmolar fluids (5% NaCl or aqua dest) for 5 min each. RESULTS The median donors age was 62 years. The median endothelial cell density of the donor corneas was 1679 cells/mm2. The median diameter of the DMEK scroll was 1.35 mm in Ringer's solution at 24 °C (IQR, 1.04 - 1.89). In Ringer's solution at different temperatures, the scrolling diameter changed between 0.02 mm and 0.29 mm. The change in osmolarity resulted in a difference of 0.02 mm to 0.46 mm. Deswelling with dextran resulted in a change of scrolling diameter between 0.02 mm and 0.09 mm. SUMMARY In this experimental case series, the diameter of the DMEK scroll did not change due to changes of temperature, osmolarity or deswelling. Influencing the graft's scroll to standardize and simplify the DMEK surgery remains an interesting goal for future studies.
Collapse
Affiliation(s)
- Markus Gruber
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg
| | | | - Katrin Wacker
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg
| | | |
Collapse
|
16
|
Dua HS, Sinha R, D'Souza S, Potgieter F, Ross A, Kenawy M, Scott I, Said DG. "Descemet Membrane Detachment": A Novel Concept in Diagnosis and Classification. Am J Ophthalmol 2020; 218:84-98. [PMID: 32574777 DOI: 10.1016/j.ajo.2020.05.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/23/2020] [Accepted: 05/25/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE To examine the optical coherence tomography (OCT) and histologic features of Descemet membrane detachment (DMD) to ascertain the involvement of the pre-Descemet layer (PDL). DESIGN Retrospective, observational case series. METHODS Clinical, histopathologic, and OCT features of a cohort of 41 cases with diagnosis of DMD from 4 centers were studied. OCT images were evaluated independently by 3 observers for number of detached layers (1 or 2), reflectivity, configuration (straight line or wavy), distance from posterior stroma, and presence or absence of a tear with any scrolling of the torn edges. Five had a histology specimen. The main outcome measure was the involvement of the PDL in DMD and its confirmation by histology. RESULTS Three types of DMD were identified: type 1, where the PDL and DM were detached together; type 2, where only the DM was detached; and mixed, where the PDL and DM were detached but also separated from each other. These were further found to be rhegmatogenous or nonrhegmatogenous depending on the presence of absence of a tear in DM or both layers. Histology confirmed involvement of PDL in all 5 cases and showed it to be infiltrated by cells in 3 of 5 cases. CONCLUSIONS The PDL is involved in DMD. This fact significantly changes our understanding of DMD and could have implications for management. The detached PDL can be infiltrated with cells. A prospective study in relation to etiology and types of DMD is needed.
Collapse
|
17
|
Espana EM, Birk DE. Composition, structure and function of the corneal stroma. Exp Eye Res 2020; 198:108137. [PMID: 32663498 PMCID: PMC7508887 DOI: 10.1016/j.exer.2020.108137] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
No other tissue in the body depends more on the composition and organization of the extracellular matrix (ECM) for normal structure and function than the corneal stroma. The precise arrangement and orientation of collagen fibrils, lamellae and keratocytes that occurs during development and is needed in adults to maintain stromal function is dependent on the regulated interaction of multiple ECM components that contribute to attain the unique properties of the cornea: transparency, shape, mechanical strength, and avascularity. This review summarizes the contribution of different ECM components, their structure, regulation and function in modulating the properties of the corneal stroma. Fibril forming collagens (I, III, V), fibril associated collagens with interrupted triple helices (XII and XIV), network forming collagens (IV, VI and VIII) as well as small leucine-rich proteoglycans (SLRP) expressed in the stroma: decorin, biglycan, lumican, keratocan, and fibromodulin are some of the ECM components reviewed in this manuscript. There are spatial and temporal differences in the expression of these ECM components, as well as interactions among them that contribute to stromal function. Unique regions within the stroma like Bowman's layer and Descemet's layer are discussed. To define the complexity of corneal stroma composition and structure as well as the relationship to function is a daunting task. Our knowledge is expanding, and we expect that this review provides a comprehensive overview of current knowledge, definition of gaps and suggests future research directions.
Collapse
Affiliation(s)
- Edgar M Espana
- Department of Molecular Pharmacology and Physiology, USA; Cornea, External Disease and Refractive Surgery, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, FL, USA
| | - David E Birk
- Department of Molecular Pharmacology and Physiology, USA.
| |
Collapse
|
18
|
|
19
|
Ross AR, Said DG, Colabelli Gisoldi RAM, Nubile M, El-Amin A, Gabr AF, Abd Ed-Moniem M, Mencucci R, Pocobelli A, Mastropasqua L, Dua HS. Optimizing pre-Descemet endothelial keratoplasty technique. J Cataract Refract Surg 2020; 46:667-674. [PMID: 32358258 DOI: 10.1097/j.jcrs.0000000000000157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Pre-Descemet endothelial keratoplasty (PDEK) is an alternative technique to Descemet membrane endothelial keratoplasty (DMEK). The preparation of PDEK tissue by pneumatic dissection is simple and reproducible. The PDEK clamp helps to consistently obtain a type 1 big bubble. The mean size of type 1 big bubble is 7.255 ± 0.535 × 6.745 ± 0.668 mm. The volume of air required to obtain type 1 big bubble is 0.14 to 0.37 mL. Dissection of PDEK tissue can be achieved by trephination or manual excision. Insertion of tissue into the recipient eye can be by injection or pulling. Unfolding techniques used for PDEK are similar to those used in DMEK. Unlike DMEK, PDEK tissue is easier to handle and unscroll and allows use of younger donors. It could help surgeons converting to endothelial keratoplasty, with significant advantages in preparation, handling, and unscrolling in the eye.
Collapse
Affiliation(s)
- Andrew R Ross
- From the Department of Ophthalmology, Nottingham University Hospitals NHS Trust and Section of Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham (Ross, Said, Dua), Nottingham, United Kingdom; Department of Ophthalmology, Aswan University (Ross, El-Amin, Gabr, Moniem), Aswan, Egypt; Hospital San Giovanni Addolorata (Colabelli Gisoldi, Pocobelli), Rome, Department of Medicine and Science of Ageing, Ophthalmic Clinic, National High Technology Eye Center, G. d'Annunzio University of Chieti (Nubile, Mastropasqua), Pescara, Department of Oto-Neuro-Ophthalmological Surgical Sciences, Eye Clinic, University of Florence (Mencucci), Florence, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Feneck EM, Souza RB, Lewis PN, Hayes S, Pereira LV, Meek KM. Developmental abnormalities in the cornea of a mouse model for Marfan syndrome. Exp Eye Res 2020; 194:108001. [PMID: 32173378 PMCID: PMC7232021 DOI: 10.1016/j.exer.2020.108001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 02/14/2020] [Accepted: 03/09/2020] [Indexed: 11/17/2022]
Abstract
Elastic fibres provide tissues with elasticity and flexibility. In the healthy human cornea, elastic fibres are limited to the posterior region of the peripheral stroma, but their specific functional role remains elusive. Here, we examine the physical and structural characteristics of the cornea during development in the mgΔloxPneo dominant-negative mouse model for Marfan syndrome, in which the physiological extracellular matrix of its elastic-fibre rich tissues is disrupted by the presence of a dysfunctional fibrillin-1 glycoprotein. Optical coherence tomography demonstrated a reduced corneal thickness in the mutant compared to wild type mice from embryonic day 16.5 until adulthood. X-ray scattering and electron microscopy revealed a disruption to both the elastic fibre and collagen fibril ultrastructure in the knockout mice, as well as abnormally low levels of the proteoglycan decorin. It is suggested that these alterations might be a result of increased transforming growth factor beta signalling. To conclude, this study has demonstrated corneal structure and ultrastructure to be altered when fibrillin-1 is disrupted and has provided insights into the role of fibrillin-1 in developing a functional cornea. mgΔloxPneo mice showed abnormalities in corneal thickness from embryonic development through to adulthood. Elastic fibres were evident from E16.5 in both the WT and mgΔloxPneo mouse corneas. Adult mgΔloxPneo mouse corneas exhibited a disorganised elastic fibre network with unusually high levels of branching. The disrupted collagen arrangement seen in adult mgΔloxPneo mice corneas is likely linked to lower levels of decorin in these corneas.
Collapse
Affiliation(s)
- Eleanor M Feneck
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Rodrigo B Souza
- Department of Genetics and Evolutionary Biology, University of Sᾶo Paulo, Rua do Matᾶo, Sᾶo Paulo, Brazil
| | - Philip N Lewis
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Sally Hayes
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Lygia V Pereira
- Department of Genetics and Evolutionary Biology, University of Sᾶo Paulo, Rua do Matᾶo, Sᾶo Paulo, Brazil
| | - Keith M Meek
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK.
| |
Collapse
|
21
|
Ting DSJ, Said DG, Dua HS. Are Descemet Membrane Ruptures the Root Cause of Corneal Hydrops in Keratoconic Eyes? Am J Ophthalmol 2019; 205:204. [PMID: 31296334 DOI: 10.1016/j.ajo.2019.04.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 04/26/2019] [Indexed: 12/26/2022]
|
22
|
Evaluation of Total Donor Endothelial Viability After Endothelium-Inward Versus Endothelium-Outward Loading and Insertion in Descemet Membrane Endothelial Keratoplasty. Cornea 2019; 39:104-109. [DOI: 10.1097/ico.0000000000002014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
23
|
Fukuoka H, Sella R, L Haynie M, Afshari NA. Adhesion Strength and Rolling Properties of Descemet Membrane Endothelial Keratoplasty Grafts in a Rabbit Eye Model. Curr Eye Res 2019; 44:929-933. [PMID: 30965016 DOI: 10.1080/02713683.2019.1606251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Purpose: To investigate the optimal time for Descemet membrane endothelial keratoplasty (DMEK) graft peeling, and to analyze the rolling properties of endothelial denuded grafts in a rabbit eye model. Materials and Methods: The vertical peeling force required to peel 1 mm wide Descemet membrane (DM) strips, was measured as the change in weight of the system during force application in a rabbit model. Twenty-one rabbit corneoscleral rims were stored in phosphate-buffered saline (PBS) at 4°C, and force analysis was performed at days 1, 5, or 21 after harvesting. After half of the strips of day 5 corneas were peeled and analyzed, the rims were moved to Optisol GS at 4°C, and the remaining strips were peeled off for force analysis at day 10. Separate DM grafts (n = 7) were analyzed by intraoperative optical coherence tomography (OCT) to determine the tissue rolling diameter before and after removal of endothelial cells by a swab. Unpaired t-test was used for statistical analysis. Results: There was a decrease in DM peeling force (p = .008) between days 1 and 5 (556.04 ± 111.76 and 324.30 ± 96.4 mg, respectively), and no difference between days 5 and 21 (p = .53). Peeling force for day 5 corneas placed in Optisol was higher at day 10 (324.30 ± 96.4 to 669.92 ± 166.24 mg, p = .005). The average rolling diameter of DM grafts was similar before and after the removal of endothelial cells (257.9 ± 131.1 and 249.8 ± 126.6 μm, respectively). Conclusions: DMEK Graft procurement could be potentially facilitated by lower DM-stromal adhesion strength at day five after obtaining corneoscleral rims, in a rabbit eye model. Time in the storage medium may influence adhesion strength. Endothelial cells do not appear to play a significant role in the rolling diameter of DM grafts.
Collapse
Affiliation(s)
- Hideki Fukuoka
- Shiley Eye Institute, Department of Ophthalmology, University of California San Diego , La Jolla , CA , USA
| | - Ruti Sella
- Shiley Eye Institute, Department of Ophthalmology, University of California San Diego , La Jolla , CA , USA
| | - Matthew L Haynie
- Shiley Eye Institute, Department of Ophthalmology, University of California San Diego , La Jolla , CA , USA
| | - Natalie A Afshari
- Shiley Eye Institute, Department of Ophthalmology, University of California San Diego , La Jolla , CA , USA
| |
Collapse
|
24
|
Lewis PN, White TL, Feneck EM, Young RD, Meek KM. Elastin Content and Distribution in Endothelial Keratoplasty Tissue Determines Direction of Scrolling. Am J Ophthalmol 2019; 197:181-182. [PMID: 30297218 DOI: 10.1016/j.ajo.2018.08.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 08/30/2018] [Indexed: 01/17/2023]
|