1
|
Sirolova Z, Polachova M, Baxant AD, Studeny P, Krivosheev K, Netukova M. A review of Bowman's layer structure, function, and transplantation. Cell Tissue Bank 2024:10.1007/s10561-024-10148-x. [PMID: 39212857 DOI: 10.1007/s10561-024-10148-x] [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: 01/23/2024] [Accepted: 08/13/2024] [Indexed: 09/04/2024]
Abstract
Bowman's layer is an acellular corneal structure, which is considered to be a specially modified anterior stroma. It is presumed, that it forms as a result of ongoing epithelial-stromal interactions and no clear physiological purpose has been proven. Despite this fact, Bowman's layer has found its place in corneal transplantation. It has been performed for over a decade, mainly in treatment of advanced keratoconus with multiple modifications. Transplantation of Bowman's layer can be expected to become a widely used surgical procedure in the treatment of many corneal pathologies involving fragmentation and destruction of Bowman's layer. This article aims to summarize information available on its structure, possible function, and transplantation. A thorough literature search was performed in the PubMed database and Google Scholar using keywords: Bowman's layer, structure, function, preparation and corneal transplantation. All the relevant sources were used, which represent 77 peer-reviewed articles with information corcerning the topic of this article.
Collapse
Affiliation(s)
- Zuzana Sirolova
- Department of Ophthalmology, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic.
- International Eye Bank of Prague, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic.
| | - Martina Polachova
- Department of Ophthalmology, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
- International Eye Bank of Prague, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
| | - Alina-Dana Baxant
- Department of Ophthalmology, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
| | - Pavel Studeny
- Department of Ophthalmology, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
- International Eye Bank of Prague, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
| | - Katarina Krivosheev
- Department of Ophthalmology, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
- International Eye Bank of Prague, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
| | - Magdalena Netukova
- Department of Ophthalmology, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
- International Eye Bank of Prague, University Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Srobarova 1150/50, 100 34, Prague 10, Czech Republic
| |
Collapse
|
2
|
Tereshchenko AV, Trifanenkova IG, Demianchenko SK, Erina YD, Golubeva YY, Pashtaev AN, Katmakov KI, Bulatov AR, Gelyastanov AM. [Alternative methods of surgical treatment of keratoconus]. Vestn Oftalmol 2024; 140:85-90. [PMID: 38742503 DOI: 10.17116/oftalma202414002185] [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] [Indexed: 05/16/2024]
Abstract
The introduction of early diagnostic methods for keratoconus into clinical practice has become the basis for the development of surgical treatment techniques for this pathology, such as corneal collagen crosslinking and interlamellar keratoplasty with implantation of intrastromal segments. The article analyzes the results of research by Russian and foreign specialists in these areas and presents the data on the combination of SMILE surgery and corneal crosslinking, the Rome protocol of corneal crosslinking, modifications of interlamellar keratoplasty, the use of femtosecond laser technologies, and some pilot studies. Modern requirements for ophthalmological care require a personalized approach to each patient, and therefore the surgeon should have a wide range of surgical methods of treatment applicable to different patient cohorts. The described methods of treatment, according to the authors, are the most promising.
Collapse
Affiliation(s)
- A V Tereshchenko
- Kaluga branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Kaluga, Russia
- Medical Institute of Kaluga State University named after K.E. Tsiolkovsky, Kaluga, Russia
| | - I G Trifanenkova
- Kaluga branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Kaluga, Russia
- Medical Institute of Kaluga State University named after K.E. Tsiolkovsky, Kaluga, Russia
| | - S K Demianchenko
- Kaluga branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Kaluga, Russia
| | - Yu D Erina
- Kaluga branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Kaluga, Russia
| | - Yu Yu Golubeva
- Kaluga branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Kaluga, Russia
| | - A N Pashtaev
- S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Moscow, Russia
| | - K I Katmakov
- Cheboksary branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Cheboksary, Russia
| | - A R Bulatov
- Kaluga branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Kaluga, Russia
| | - A M Gelyastanov
- Kaluga branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", Kaluga, Russia
| |
Collapse
|
3
|
Orive Bañuelos A, Santamaría Carro A, Feijóo Lera R, Etxebarria Ecenarro J. Sterile corneal necrosis after bowman layer transplantation. Eur J Ophthalmol 2023:11206721231165438. [PMID: 36945822 DOI: 10.1177/11206721231165438] [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: 03/23/2023]
Abstract
Purpose: To report sterile corneal necrosis as a severe and rare complication after Bowman Layer Transplantation (BTL). Methods: A 35-year-old woman with Down syndrome and advanced progressive keratoconus in her left eye was scheduled for a BLT. The patient rubbed her eyes and did not tolerate contact lenses. Following standard technique, a 8mm Bowman layer graft was placed into a intrastromal pocket with no intraoperative complications. Results: Postoperatively, the patient remained stable and topography showed notable central flattening but 17 days after the BTL was performed she developed a sterile corneal necrosis. Conclusions: Many studies have proven the efficacy of this technique as a potential treatment for stabilizing progressive and advanced keratoconus in selected cases. Few complications associated with BTL have been reported, including Bowman Layer tears or buttonholes when obtaining the tissue, very thick grafts or postoperative hydrops but no sterile necrosis described to the date. A combination of the hypotheses raised in this paper may explain this undesirable event.
Collapse
Affiliation(s)
- Ana Orive Bañuelos
- Department of Ophthalmology, BioCruces Bizkaia Health Research Institute, 16494University Hospital of Cruces, Barakaldo, Spain
| | - Alaitz Santamaría Carro
- Department of Ophthalmology, BioCruces Bizkaia Health Research Institute, 16494University Hospital of Cruces, Barakaldo, Spain
| | - Raquel Feijóo Lera
- Department of Ophthalmology, BioCruces Bizkaia Health Research Institute, 16494University Hospital of Cruces, Barakaldo, Spain
| | - Jaime Etxebarria Ecenarro
- Department of Ophthalmology, BioCruces Bizkaia Health Research Institute, 16494University Hospital of Cruces, Barakaldo, Spain
- Department of Cell Biology and Histology, 58349School of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| |
Collapse
|
4
|
Oganesyan OG, Ashikova PM, Ivanova AV, Letnikova KB. [Transplantation of the Bowman's layer in combined treatment of recurrent pterygium]. Vestn Oftalmol 2023; 139:90-97. [PMID: 37379114 DOI: 10.17116/oftalma202313903190] [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: 06/30/2023]
Abstract
Pterygium is among the most frequent indications for extraocular ophthalmic surgery. The main method of pterygium treatment - its excision - is often combined with transplantation, non-transplantation, medication and other methods. However, the frequency of pterygium recurrence can exceed 35%, and the cosmetic and refraction outcomes satisfy neither the patient, nor the surgeon. PURPOSE The study analyses the technical capability and feasibility for transplantation of the Bowman's layer in the treatment of recurrent pterygium. MATERIAL AND METHODS The transplantation of the Bowmen's layer was performed according to the developed technique on 7 eyes with recurrent pterygium (7 patients aged 34 to 63 years). The combined surgery technique consisted of pterygium resection, laser ablation, autoconjunctival plasty, exposure to a cytostatic drug, non-suture transplantation of the Bowman's layer. Maximum length of the follow-up was 36 months. Analysis involved data from refractometry, visometry (without correction and with spectacle correction), and optical coherence tomography of the retina. RESULTS There were no complications in any of the studied cases. The cornea and the transplant retained transparency throughout the entire follow-up duration. 36 months after surgery mean spectacle-corrected visual acuity amounted to 0.86±0.2, topographic astigmatism - 1.48±1.4 diopters. Recurrence of pterygium was not observed. All patients were satisfied with the cosmetic outcomes of the treatment. CONCLUSION Non-suture transplantation of the Bowmen's layer recovers normal anatomy, physiology and transparency of the cornea after repeat surgical intervention for pterygium. No pterygium recurrences were observed throughout the entire follow-up after treatment with the proposed combined technique.
Collapse
Affiliation(s)
- O G Oganesyan
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - P M Ashikova
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - A V Ivanova
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - K B Letnikova
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| |
Collapse
|
5
|
Bowman Layer Onlay Graft for Recurrent Corneal Erosions in Map–Dot–Fingerprint Dystrophy. Cornea 2022; 41:1062-1063. [DOI: 10.1097/ico.0000000000002988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022]
|
6
|
Bowman's layer transplantation in advanced keratoconus; 18-months outcomes. Int Ophthalmol 2021; 42:1161-1173. [PMID: 34767125 DOI: 10.1007/s10792-021-02101-8] [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: 11/06/2020] [Accepted: 10/21/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE To assess the outcome of isolated Bowman's layer transplantation (BLT) in advanced keratoconus in the patients not suitable for ultra violet cross-linking and intra stromal corneal ring segments. STUDY DESIGN Nonrandomized Quasi-Experimental. MATERIALS AND METHODS Mid corneal stromal dissection followed by implantation of manually isolated bowman layer from a donor into the recipient stromal pocket was performed in the Department of Ophthalmology Khyber Teaching Hospital Peshawar from September 2018 to October 2018 and followed up over 18 months. RESULTS Eleven eyes of 11 patients, 8 male and 3 female within the age range of 7-28 years with progressive keratoconus went under BLT All keratometry values decreased after surgery. Mean anterior pre-operative SimK changed from 69.05 ± 10.85 D to 61.14 ± 6.23 D at 18 months post-operatively (P = 0.005). Means pre-operative Kmax value decreased from 77.24 ± 7.58 D to 71.07 ± 5.37 D at 18 months post-operatively (p = 0.060). The mean pre-operative posterior keratometry value changed from - 10.03 ± 0.88 to - 8.96 ± 1.06 D at 18 months post-operatively (P = 0.002). Mean pre-operative thinnest corneal thickness increased from 281.64 ± 196.86 um to 355.27 ± 19.17 um at 18th months post-operatively (P = 0.001). Pachymetry p-value pre-operative to 18 months (P = 0.001) was statistically significant. Mean anterior SimK at 6 months post-operatively, 60.55 ± 5.56D changed to 61.14 ± 6.23D at 18 months post-operatively (P = 0.000), Kmax at 6 months postoperative 71.60 ± 5.01 D changed to 71.07 ± 5.37 D at 18 months post-operatively (P = 0.008). Both anterior K values at 6 months and 18 months post-operatively showed less significant change, and the same was true for Kmax data at 6 months and 18 months post-operatively. P-values at 6 months to 18 months post-operatively for cornea back data remained (P = 0.001) unchanged. No complications were observed intra-operatively or post-operatively. CONCLUSION Bowman layer transplantation is a unique surgical treatment for advanced keratoconus to stabilize progressive ectasia with fewer complications avoiding the need for penetrating or deep anterior lamellar keratoplasty.
Collapse
|
7
|
Peris-Martínez C, García-Domene MC, Penadés M, Luque MJ, Fernández-López E, Artigas JM. Spectral Transmission of the Human Corneal Layers. J Clin Med 2021; 10:jcm10194490. [PMID: 34640506 PMCID: PMC8509317 DOI: 10.3390/jcm10194490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 11/16/2022] Open
Abstract
We have assessed the spectral transmittance of the different layers of the human cornea in the ultraviolet (UV), visible, and near-infrared (IR) spectral ranges. Seventy-four corneal sample donors were included in the study. Firstly, the corneal transmittance was measured using a spectrophotometer. Then, all samples were fixed for histopathological analysis, which allowed us to measure the thickness of each corneal layer. Finally, the absorption coefficients of the corneal layers were computed by a linear model reproducing total transmittance. The results show that corneal transmission was almost in unity at the visible and IR ranges but not at the UV range, in which the layer with higher transmission is Descemet’s membrane, whereas the stroma showed the lowest transmittance. Regarding the absorption coefficient, the most absorptive tissue was Bowman’s layer, followed by the endothelium. Variations on transmittance due to changes in the stroma, Bowman’s layer, or Descemet layer were simulated, and important transmission increases were found due to stroma and Bowman changes. To conclude, we have developed a method to measure the transmittance and thickness for each corneal layer. All corneal layers absorb UV light to a greater or lesser extent. The absorption coefficient is higher for Bowman’s layer, while the stroma is the layer with the lowest transmittance due to its thickness. Variations in stroma thickness or changes in the corneal tissue of Bowman’s layer or the endothelium layer due to some pathologies or surgeries could affect, to a greater or lesser degree, the total transmission of the cornea. Thus, obtaining accurate absorption coefficients for different layers would help us to predict and compensate these changes.
Collapse
Affiliation(s)
- Cristina Peris-Martínez
- Anterior Segment and Cornea and External Eye Diseases Unit, FISABIO-Oftalmología Médica (FOM), Av. Pío Baroja, 12, E-46015 Valencia, Spain; (M.C.G.-D.); (M.P.); (M.J.L.); (E.F.-L.); (J.M.A.)
- Surgery Department, Ophthalmology, School of Medicine, University of Valencia, Av. Blasco Ibáñez, 15, E-46010 Valencia, Spain
- Department of Optics and Optometry and Vision Sciences, Physics School, University of Valencia, Dr. Moliner, 50, E-46100 Valencia, Spain
- Correspondence: ; Tel.: +34-962-787620
| | - Mari Carmen García-Domene
- Anterior Segment and Cornea and External Eye Diseases Unit, FISABIO-Oftalmología Médica (FOM), Av. Pío Baroja, 12, E-46015 Valencia, Spain; (M.C.G.-D.); (M.P.); (M.J.L.); (E.F.-L.); (J.M.A.)
- Department of Optics and Optometry and Vision Sciences, Physics School, University of Valencia, Dr. Moliner, 50, E-46100 Valencia, Spain
- Thematic Cooperative Health Network for Research in Ophthalmology (Oftared), Carlos III Health Institute, C/Sinesio Delgado, 4, E-28029 Madrid, Spain
| | - Mariola Penadés
- Anterior Segment and Cornea and External Eye Diseases Unit, FISABIO-Oftalmología Médica (FOM), Av. Pío Baroja, 12, E-46015 Valencia, Spain; (M.C.G.-D.); (M.P.); (M.J.L.); (E.F.-L.); (J.M.A.)
- Thematic Cooperative Health Network for Research in Ophthalmology (Oftared), Carlos III Health Institute, C/Sinesio Delgado, 4, E-28029 Madrid, Spain
- Pathology Group, PASAPTA, Veterinary School, Cardenal Herrera-CEU University, C/Tirant lo Blanc, 7, E-46115, Alfara del Patriarca, E-46115 Valencia, Spain
| | - María Josefa Luque
- Anterior Segment and Cornea and External Eye Diseases Unit, FISABIO-Oftalmología Médica (FOM), Av. Pío Baroja, 12, E-46015 Valencia, Spain; (M.C.G.-D.); (M.P.); (M.J.L.); (E.F.-L.); (J.M.A.)
- Department of Optics and Optometry and Vision Sciences, Physics School, University of Valencia, Dr. Moliner, 50, E-46100 Valencia, Spain
| | - Ester Fernández-López
- Anterior Segment and Cornea and External Eye Diseases Unit, FISABIO-Oftalmología Médica (FOM), Av. Pío Baroja, 12, E-46015 Valencia, Spain; (M.C.G.-D.); (M.P.); (M.J.L.); (E.F.-L.); (J.M.A.)
| | - José María Artigas
- Anterior Segment and Cornea and External Eye Diseases Unit, FISABIO-Oftalmología Médica (FOM), Av. Pío Baroja, 12, E-46015 Valencia, Spain; (M.C.G.-D.); (M.P.); (M.J.L.); (E.F.-L.); (J.M.A.)
- Department of Optics and Optometry and Vision Sciences, Physics School, University of Valencia, Dr. Moliner, 50, E-46100 Valencia, Spain
- Thematic Cooperative Health Network for Research in Ophthalmology (Oftared), Carlos III Health Institute, C/Sinesio Delgado, 4, E-28029 Madrid, Spain
| |
Collapse
|
8
|
Abstract
PURPOSE To introduce the concept of using a Bowman layer (BL) onlay graft to manage superficial herpetic corneal scarring and to describe the clinical outcomes of the first 2 cases undergoing this procedure. METHODS Two patients with a quiescent superficial corneal scar after herpes (varicella zoster virus [n = 1] and herpes simplex virus [n = 1]) keratitis underwent BL onlay transplantation. After the removal of the host epithelium and limited superficial keratectomy, an isolated BL graft was placed onto the host corneal surface. The cornea was then covered with an amniotic membrane and a bandage contact lens. Best spectacle-corrected visual acuity (VA) and/or best contact lens-corrected VA (BCLVA), biomicroscopy, corneal tomography, and anterior segment optical coherence tomography were recorded at 1 week, 1 month, and 3, 6, 9, 12, and 18 months postoperatively. RESULTS In both cases, the surgical and postoperative courses were uneventful. An improvement of the corneal clarity was observed at biomicroscopy, and no varicella zoster virus/herpes simplex virus reactivation occurred throughout the follow-up period. Biomicroscopy, Scheimpflug imaging, and anterior segment optical coherence tomography showed a completely epithelialized and well-integrated graft postoperatively. In case 1, BCLVA with a scleral lens improved from 20/100 (0.1) preoperatively to 20/32 (0.6) postoperatively. For case 2, no preoperative BCLVA was available, but a BCLVA of 20/36 (0.55) was achieved after the procedure. CONCLUSIONS A BL onlay graft may be a feasible surgical procedure, which may have the potential to reduce superficial corneal scarring and/or anterior corneal irregularities without resorting to deeper keratoplasty in these complex cases.
Collapse
|
9
|
García de Oteyza G, Benedetti Sandner M, Velazco Casapía J, Triviño C, Salvador-Culla B, García-Albisua AM. Intrastromal Allogeneic Inclusions for the Management of Keratoconus: A Review of Current Literature. Cornea 2021; 40:794-799. [PMID: 33591036 DOI: 10.1097/ico.0000000000002658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/27/2020] [Indexed: 11/26/2022]
Abstract
ABSTRACT A new therapeutic alternative has been developed in the past 6 years to treat severe keratoconus in young patients. Those patients had only corneal transplantation as an option, but now a variety of surgical alternatives in the form of allogeneic corneal inclusions have bloomed and are becoming more popular. Although Bowman layer transplantation is the most studied technique, recent studies have described different options with very promising preliminary results. Mostly all the techniques described improve corneal curvature, visual acuity, pachymetry, contact lens tolerance, and foremost, manage to avoid or postpone corneal transplantation. Very few complications have been described so far, which makes these techniques not only feasible but also safe. Herein, we focus on reviewing recently published studies describing these techniques and their first results.
Collapse
Affiliation(s)
- Gonzalo García de Oteyza
- Clínica Oftalmológica García de Oteyza, Barcelona, Spain
- Cornea and Refractive Surgery Department, Asociación Para Evitar la Ceguera en México, Hospital "Luis Sánchez Bulnes," México City, México
| | - Mónica Benedetti Sandner
- Cornea and Refractive Surgery Department, Asociación Para Evitar la Ceguera en México, Hospital "Luis Sánchez Bulnes," México City, México
| | | | | | - Borja Salvador-Culla
- Cornea and Refractive Surgery Department, Centro de Oftalmología Barraquer, Barcelona, Spain
| | - Ana Mercedes García-Albisua
- Cornea and Refractive Surgery Department, Asociación Para Evitar la Ceguera en México, Hospital "Luis Sánchez Bulnes," México City, México
| |
Collapse
|
10
|
Parker J, Dockery P, Preda-Naumescu A, Jager M, van Dijk K, Dapena I, Melles G. Descemet Membrane Endothelial Keratoplasty and Bowman Layer Transplantation: An Anatomic Review and Historical Survey. Ophthalmic Res 2021; 64:532-553. [PMID: 33761502 DOI: 10.1159/000516093] [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: 12/10/2020] [Accepted: 03/23/2021] [Indexed: 11/19/2022]
Abstract
For nearly a century, the definitive treatment of many corneal dystrophies and ectactic disorders was limited to penetrating keratoplasty, but over the past 2 decades, a surge of surgical innovation has propelled the treatment of many corneal diseases to more targeted approaches with significantly better visual outcomes. Anterior stromal diseases were first changed through endothelial-sparing techniques, such as deep anterior lamellar keratoplasty, but have more recently transitioned to stromal-sparing approaches. Ultraviolet corneal crosslinking strengthens the cornea and halts progression of keratoconus in >90% of cases. Intracorneal ring segment and corneal allogenic ring segment implantation offer methods to flatten ectatic corneas. However, Bowman layer transplantation - inlay and more recently onlay techniques - has shown promise for treating advanced keratoconus and preventing keratoplasty. The advent of endothelial keratoplasty radically changed the treatment of corneal endothelial dysfunction, and Descemet membrane endothelial keratoplasty specifically offers an average postoperative visual acuity of 20/25 (0.8) with only 8.8% of grafts requiring retransplantation in the first 5 years. Here, we review the rapid innovations for surgical treatment of corneal diseases, spanning from endothelial keratoplasty and endothelial regeneration to anterior lamellar keratoplasty and stromal augmentation, highlighting key steps which may be moving us closer to a "postkeratoplasty" world.
Collapse
Affiliation(s)
- Jack Parker
- Parker Cornea, Birmingham, Alabama, USA.,Netherlands Institute for Innovative Ocular Surgery- USA (NIIOS-USA), San Diego, California, USA
| | - Philip Dockery
- Parker Cornea, Birmingham, Alabama, USA.,Wills Eye Hospital, Philadelphia, Pennsylvania, USA
| | - Ana Preda-Naumescu
- University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Martine Jager
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Korine van Dijk
- Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, The Netherlands.,Melles Cornea Clinic Rotterdam, Rotterdam, The Netherlands
| | - Isabel Dapena
- Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, The Netherlands.,Melles Cornea Clinic Rotterdam, Rotterdam, The Netherlands
| | - Gerrit Melles
- Parker Cornea, Birmingham, Alabama, USA.,Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, The Netherlands.,Melles Cornea Clinic Rotterdam, Rotterdam, The Netherlands
| |
Collapse
|
11
|
Abstract
Bowman layer (BL) transplantation has been described for various indications, including the treatment of postrefractive corneal haze, postherpetic scarring, and keratoconus. The unique properties of the BL explain its versatility. Robust, thin, and acellular, transplanted BL inhibits stromal scarring, flattens ectatic corneas, and poses minimal risk of immune reaction. This article reviews the history of BL transplantation and recent developments, and anticipated next steps for the procedure.
Collapse
Affiliation(s)
- Jack S Parker
- Parker Cornea, Birmingham, AL
- Netherlands Institute for Innovative Ocular Surgery-USA (NIIOS-USA), San Diego, CA
| | | | - Gerrit R J Melles
- Netherlands Institute for Innovative Ocular Surgery-USA (NIIOS-USA), San Diego, CA
- Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, the Netherlands
- Melles Cornea Clinic Rotterdam, Rotterdam, the Netherlands
| |
Collapse
|
12
|
Establishing a Porcine Eye Model for Manual Sub-Bowman Layer Photorefractive Keratomileusis. J Ophthalmol 2020; 2020:9834760. [PMID: 32733701 PMCID: PMC7378610 DOI: 10.1155/2020/9834760] [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: 02/29/2020] [Revised: 04/26/2020] [Accepted: 06/22/2020] [Indexed: 11/17/2022] Open
Abstract
Objective To establish a porcine eye model for manual sub-Bowman layer photorefractive keratomileusis (SBPRK), which is a reformed surface ablation refractive surgery that results in preserving the corneal Bowman layer (BL). Methods The SBPRK group consisted of eleven eyes of 8 healthy pigs with BL flaps by mechanical technique followed by laser ablation. Regarding the remaining 5 eyes, 3 random eyes had transepithelium photorefractive keratectomy (TransPRK) (the TransPRK group), while the other 2 eyes were untreated (the blank control group). All the pigs were followed up for 8 weeks. Slit-lamp biomicroscopy and optical coherence tomography (OCT) were examined before the surgeries and at 1 week, 4 weeks, and 8 weeks after the surgeries. Results In a few days after the surgery, 3 eyes of the SBPRK group were excluded from the study because of poor healing of the corneal flaps. At the 1st postoperative week, one eye had an irregular defect of about 3 mm in the central corneal epithelium area; the cornea of the other 7 eyes had just light edema with intact epithelium just like the cornea of the TransPRK group. At the 4th week, in the SBPRK group, the cornea was slightly hazy (haze stage 1). While in the TransPRK group, the cornea was hazier (haze stage 2). At the 8th week, in the SBPRK group, both corneas were almost transparent, and the edges of the BL flaps could not be clearly seen. Meanwhile, in the TransPRK group, the corneal haze became lighter and thinner. OCT showed that, in the SBPRK group, there was high reflection in the BL layer, and it was obvious at 1 week postoperation, decreased at 4 weeks, and calmed down at 8 weeks. However, in the TransPRK group, the high reflection diffused in the anterior corneal stroma at 1 week postoperation, enhanced at 4 weeks, and weakened at 8 weeks. Conclusions Preserving the BL while conducting surface refractive surgery may result in less haze than TransPRK. However, further study is still needed, and this technique still requires refining until it becomes a standard clinical procedure.
Collapse
|
13
|
Abstract
PURPOSE OF REVIEW Bowman layer transplantation is a novel technique that may stabilize progressive ectatic corneal changes in eyes with keratoconus, which are too steep or too thin for ultraviolet corneal crosslinking or intracorneal ring segments. In this way, patients can maintain stable vision with contact lenses, and avoid or postpone more invasive corneal transplants, such as penetrating keratoplasty or deep anterior lamellar keratoplasty. This review aims to summarize the currently available literature on Bowman layer transplantation. RECENT FINDINGS Bowman layer transplantation seems to be a promising, minimally invasive procedure for managing advanced keratoconus with a reported 5-year success rate of 84%. The procedure allows patients to maintain acceptable visual acuity with glasses or contact lens correction. Although graft preparation and surgical technique can be challenging, adaptation of technologies, such as femtosecond laser and intraoperative anterior segment optical coherence tomography, may help overcome these barriers to enable Bowman layer transplantation to become a more widely adopted procedure. SUMMARY Bowman layer transplantation may offer an alternative, less invasive treatment option for eyes with advanced, progressive keratoconus.
Collapse
|
14
|
Myerscough J, Bovone C, Thomas PBM, Mimouni M, Aljassar F, Padroni S, Busin M. Sutureless superficial anterior lamellar keratoplasty for recurrent corneal haze after repeat excimer laser surface ablation. Br J Ophthalmol 2019; 104:341-344. [DOI: 10.1136/bjophthalmol-2019-314316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/20/2019] [Accepted: 06/11/2019] [Indexed: 11/03/2022]
Abstract
Background/AimsTo evaluate the 5-year outcomes of sutureless superficial anterior lamellar keratoplasty (SALK) in the treatment of surface ablation-related corneal haze recurring after phototherapeutic keratectomy (PTK).MethodsProspective interventional study at a tertiary referral centre in Forli, Italy. Ten consecutive eyes with corneal haze following photorefractive keratectomy, recurring after treatment with PTK with or without mitomycin C, undergoing sutureless SALK. Sutureless SALK was performed using a microkeratome in donor and recipient. Main outcome measures: best spectacle-corrected visual acuity (BSCVA), surgically induced astigmatism (SIA), rate of recurrence and complications.ResultsThere were no intraoperative complications and there was no recurrence of haze in any eye postoperatively. BSCVA showed significant improvement at all postoperative time points. Mean preoperative visual acuity improved from 0.46 logMAR units (SD=0.12) to 0.12 (SD=0.12, p=0.0001) at 5 years. At 6 months, SIA was 2.50±1.04 with no further significant change at 5 years (2.53±1.39, p=0.95). There was no significant change in mean spherical equivalent and no significant difference between preoperative and postoperative astigmatism vector values at 5 years.ConclusionsSutureless SALK provides a useful treatment option in patients with recurrent haze after excimer laser treatment. It can eliminate haze recurrence for at least a period of 5 years and can improve BSCVA, although there may be significant SIA.
Collapse
|
15
|
Demarcation Line in the Human Cornea After Surface Ablation Observed by Optical Coherence Tomography and Confocal Microscopy. Eye Contact Lens 2018; 44 Suppl 2:S19-S23. [PMID: 29210827 DOI: 10.1097/icl.0000000000000459] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate the long-term changes in anterior corneal structure after surface ablation. METHODS In this retrospective study, patients who received surface ablation including laser-assisted subepithelial keratomileusis (LASEK) and epipolis laser in situ keratomileusis at the Department of Ophthalmology of Fudan University Eye and Ear, Nose and Throat (EENT) Hospital (Shanghai, People's Republic of China) were telephoned. Patients were asked to follow-up at the refractive center. Changes in the anterior cornea (from the epithelium to the anterior stroma) were examined by optical coherence tomography (OCT) and in vivo confocal microscopy. RESULTS Thirty-four eyes of 18 patients (10 years or more after operation), 16 eyes of 8 patients (4 years after operation), 12 eyes of 6 patients (1 year after operation), 8 eyes of 4 patients (6 months after operation), and 12 eyes of 6 patients (1 month after operation) were included. Under OCT, a smooth, continuous, and highly reflective demarcation line between the epithelial layer and the stroma was noted in all eyes that received surgeries more than 1 year previously. For eyes at 6 months after operation, the complete formation of this demarcation line was detected in 12.5% (1/8) of eyes and a partial formation of this demarcation line was observed in 87.5% (7/8) of eyes. A partial formation of this demarcation line was observed in 100% (12/12) of eyes in patients at 1 month after surgery. CONCLUSIONS A demarcation line in the human cornea can be detected after corneal surface ablation. It was completely formed around postoperative 6 to 12 months. The functions and components of this structure merit investigation.
Collapse
|
16
|
Dragnea DC, Birbal RS, Ham L, Dapena I, Oellerich S, van Dijk K, Melles GRJ. Bowman layer transplantation in the treatment of keratoconus. EYE AND VISION 2018; 5:24. [PMID: 30238016 PMCID: PMC6139901 DOI: 10.1186/s40662-018-0117-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/27/2018] [Indexed: 12/18/2022]
Abstract
Several treatment options corresponding to the grade of keratoconus have been established. These are ultra-violet corneal crosslinking and intracorneal ring segments for mild to moderate keratoconus, and penetrating keratoplasty or deep anterior lamellar keratoplasty for the more advanced cases of keratoconus. Bowman layer transplantation was developed as a procedure for patients with advanced, progressive keratoconus. The technique consists of transplanting an isolated donor Bowman layer into a mid-stromal pocket of a keratoconic cornea resulting in corneal flattening and stabilization against further ectasia. Thus, it aims at corneal stabilization in eyes with advanced keratoconus, and enabling continued contact lens wear for normal visual functionality. By being a sutureless procedure and using an acellular graft, it potentially avoids commonly known suture and graft-related complications of penetrating or deep anterior lamellar keratoplasty. The treatment seems to be a promising option in the management of advanced keratoconus in order to postpone or prevent a more invasive corneal surgery, while minimizing the risk of complications and allowing less stringent surveillance and less intensive medical therapy.
Collapse
Affiliation(s)
- Diana C Dragnea
- 1Netherlands Institute for Innovative Ocular Surgery (NIIOS), Laan op Zuid 88, 3071AA Rotterdam, The Netherlands.,Melles Cornea Clinic, Rotterdam, The Netherlands
| | - Rénuka S Birbal
- 1Netherlands Institute for Innovative Ocular Surgery (NIIOS), Laan op Zuid 88, 3071AA Rotterdam, The Netherlands.,Melles Cornea Clinic, Rotterdam, The Netherlands.,Amnitrans EyeBank, Rotterdam, The Netherlands
| | - Lisanne Ham
- 1Netherlands Institute for Innovative Ocular Surgery (NIIOS), Laan op Zuid 88, 3071AA Rotterdam, The Netherlands.,Melles Cornea Clinic, Rotterdam, The Netherlands.,Amnitrans EyeBank, Rotterdam, The Netherlands
| | - Isabel Dapena
- 1Netherlands Institute for Innovative Ocular Surgery (NIIOS), Laan op Zuid 88, 3071AA Rotterdam, The Netherlands.,Melles Cornea Clinic, Rotterdam, The Netherlands
| | - Silke Oellerich
- 1Netherlands Institute for Innovative Ocular Surgery (NIIOS), Laan op Zuid 88, 3071AA Rotterdam, The Netherlands
| | - Korine van Dijk
- 1Netherlands Institute for Innovative Ocular Surgery (NIIOS), Laan op Zuid 88, 3071AA Rotterdam, The Netherlands.,Melles Cornea Clinic, Rotterdam, The Netherlands
| | - Gerrit R J Melles
- 1Netherlands Institute for Innovative Ocular Surgery (NIIOS), Laan op Zuid 88, 3071AA Rotterdam, The Netherlands.,Melles Cornea Clinic, Rotterdam, The Netherlands.,Amnitrans EyeBank, Rotterdam, The Netherlands.,NIIOS-USA, San Diego, USA
| |
Collapse
|
17
|
Abstract
Lamellar keratoplasty (LK) has revolutionized corneal graft surgery in several ways. Deep anterior LK (DALK) has eliminated risk of failure due to endothelial rejection. Endothelial keratoplasty (EK) has almost eliminated induced astigmatism and the “weak” graft–host junction as seen with penetrating keratoplasty (PK) and also reduced the risk of endothelial rejection. LK provided new insights into posterior corneal anatomy that led to better understanding and performance of DALK and to the development of another EK procedure, namely pre-Descemet's EK (PDEK). Surgical procedures for LK were further refined based on the improved understanding and are able to deliver better surgical outcomes in terms of structural integrity and long-term patient satisfaction, reducing the need of further surgeries and minimizing patient discomfort. In most specialist centers, anterior lamellar techniques like DALK and EK techniques like Descemet's stripping EK (DSEK) and Descemet's membrane EK (DMEK) have replaced the full-thickness PK where possible. The introduction of microkeratome, femtosecond laser, and PDEK clamp have made LK techniques easier and more predictable and have led to the innovation of another LK procedure, namely Bowman membrane transplant (BMT). In this article, we discuss the evolution of different surgical techniques, their principles, main outcomes, and limitations. To date, experience with BMT is limited, but DALK has become the gold standard for anterior LK. The EK procedures too have undergone a rapid transition from DSEK to DMEK and PDEK emerging as a viable option. Ultrathin-DSEK may still have a role in modern EK.
Collapse
Affiliation(s)
- Nadisha P Singh
- Division of Clinical Neuroscience, University of Nottingham, UK
| | - Dalia G Said
- Queen's Medical Centre, Nottingham University Hospitals NHS Trust; Division of Clinical Neuroscience, University of Nottingham, UK
| | | |
Collapse
|
18
|
Ibrahim T, Goernert P, Rocha G. Femto-second laser (FSL) techniques and consistency in corneal surgery: experimental study. Can J Ophthalmol 2018; 53:324-329. [PMID: 30119784 DOI: 10.1016/j.jcjo.2017.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 10/31/2017] [Accepted: 11/07/2017] [Indexed: 10/17/2022]
Abstract
OBJECTIVE To investigate the feasibility, effectiveness, and reproducibility of femtosecond laser (FSL) technology in different corneal cuts. DESIGN Experimental study at the Brandon Regional Health Centre. PARTICIPANTS Twenty two Human Cadaver eyes donated for research and supplied by the eye bank of Manitoba university. METHODS In this experimental study, the effectiveness and reproducibility of FSL were investigated in different corneal cuts. The corneas were divided into 5 groups: group I for penetrating keratoplasty; group II for anterior lamellar keratoplasty; group III for corneal pockets for inlays; group IV for intracorneal ring tunnels; and group V for corneal cross-linking pockets. Our primary endpoint was the repeatability of planned versus obtained thickness and diameter of the cuts with FSL. A secondary endpoint was the effectiveness and ease of dissection, rated from 0-4, with 4 being the easiest and 0 the most difficult to dissect. RESULTS There was a high correlation between planned and obtained thickness (r = 0.997, p < 0.001) and diameter (r = 0.998, p < 0.001). Both were statistically significant. Linear regression analyses showed that the obtained thickness of corneal cuts in micrometers was significantly predicted by the planned thickness of corneal cuts in micrometers (β = 0.996, t = 56.47, p < 0.001). Likewise, the obtained diameter of corneal cuts in millimeters was significantly predicted by the planned diameter of corneal cuts in millimeters (β = 0.971, t = 70.85, p < 0.001). The surgeons gave 15 out of a total of 22 corneas (68.2%) the maximum score for ease of dissection (Grade 4), where no adhesions were found and the dissection was smooth and steady. Five corneas out of a total of 22 (22.7%) were given a score of 3 of 4 where minor adhesions were found. Two corneas out of a total of 22 (9.1%) were given a score of 2 of 4 where >1 adhesion was found, with some difficulty in separating the cut cornea from the bed. No corneas were given grade 1 or grade 0. No significant differences were obtained for the ease of dissection among the 5 surgery types using Kruskal-Wallis H test (H [4] = 4.971, p > 0.05). CONCLUSION The measured corneal-cut geometry correlated well with laser settings in a variety of full- and partial-thickness FSL corneal patterns, including different depths and diameters. This reproducible efficacy and measurement accuracy of the planned versus obtained cuts could have a favourable result on a variety of corneal surgeries. It also yields a favourable ease of dissection of the cut lenticule from the stromal bed.
Collapse
Affiliation(s)
- Tarek Ibrahim
- Ocular Microsurgery & Laser Centre, Brandon, Man.; Eye Consultant Centre, Dubai, United Arab Emirates.
| | | | - Guillermo Rocha
- Ocular Microsurgery & Laser Centre, Brandon, Man.; Department of Ophthalmology, University of Manitoba, Winnipeg, Man.; Brandon Regional Health Centre, Prairie Mountain Health, Brandon, Man
| |
Collapse
|
19
|
Sharma B, Dubey A, Prakash G, Vajpayee RB. Bowman's layer transplantation: evidence to date. Clin Ophthalmol 2018; 12:433-437. [PMID: 29551887 PMCID: PMC5842778 DOI: 10.2147/opth.s141127] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Surgical management of keratoconus (KC) has undergone a paradigm shift in the last two decades and component corneal transplantation technique of deep anterior lamellar keratoplasty has established itself as a modality of choice for management of advanced cases of KC. Every now and then, new minimalist modalities are being innovated for the management of KC. On the same lines, a new technique, Bowman's layer transplantation, for surgical management of moderate to advanced KC has been reported in recent years. The procedure has shown to be beneficial in reducing ectasia in advanced KC with minimal intraoperative and postoperative complications. In this review, we intend to describe available information and literature with reference to this new surgical technique - Bowman's layer transplantation.
Collapse
Affiliation(s)
- Bhavana Sharma
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Aditi Dubey
- Department of Ophthalmology, Gandhi Medical College, Bhopal, India
| | - Gaurav Prakash
- Cornea and Refractive Surgery Services, NMC Eye Care, New Medical Center Specialty Hospital, Abu Dhabi, United Arab Emirates
| | - Rasik B Vajpayee
- Vision Eye Institute, Melbourne, VIC, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,North West Academic Centre, University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
20
|
Abstract
PURPOSE To describe and compare 2 preparation techniques for Bowman layer (BL) grafts for use in BL transplantation. METHODS A retrospective evaluation of the 2 methods for preparing BL grafts was performed, that is, BL graft preparation from donor globes not eligible for penetrating keratoplasty or endothelial keratoplasty (technique I, n = 36) and BL graft preparation from previously excised corneoscleral buttons (technique II, n = 36) that could not be used for PK or had been denuded of Descemet membrane and endothelium for Descemet membrane endothelial keratoplasty graft preparation. BL graft preparation difficulties were recorded, and the preparation failure rate was examined and compared between the techniques. RESULTS Overall, BL graft preparation was successful in 51 cases (51/72; 70.8%), of which 25 preparations were successful using technique I, and 26 using technique II, representing a success rate of 69.4% (25/36) and 72.2% (26/36) for techniques I and II, respectively. Reasons for discarding a BL graft were tearing of the BL tissue during the preparation (n = 19) and stroma attached to the graft (n = 2). CONCLUSIONS Isolated BL grafts can be prepared from both whole donor globes and corneoscleral rims with equivalent success. Preparation from corneoscleral rims may offer the advantage that, from one donor cornea, the posterior layers can be used for Descemet membrane endothelial keratoplasty graft preparation and the anterior part for BL graft preparation.
Collapse
|
21
|
Andreanos KD, Hashemi K, Petrelli M, Droutsas K, Georgalas I, Kymionis GD. Keratoconus Treatment Algorithm. Ophthalmol Ther 2017; 6:245-262. [PMID: 28755306 PMCID: PMC5693837 DOI: 10.1007/s40123-017-0099-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Indexed: 11/25/2022] Open
Abstract
Keratoconus management has significantly changed over the last two decades. The advent of new interventions such as cornea cross-linking, intrastromal corneal ring segments, and combined treatments provide corneal clinicians a variety of treatment options for the visual rehabilitation of keratoconus patients. This review summarizes current evidence for these treatments and highlights their place in keratoconus management while new promising emerging therapies are being investigated.
Collapse
Affiliation(s)
- Konstantinos D Andreanos
- 1st Department of Ophthalmology, 'G. Gennimatas Hospital', National and Kapodistrian University of Athens, Athens, Greece.
| | - Kate Hashemi
- Faculty of Biology and Medicine, Jules Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
| | - Myrsini Petrelli
- 1st Department of Ophthalmology, 'G. Gennimatas Hospital', National and Kapodistrian University of Athens, Athens, Greece
| | - Konstantinos Droutsas
- 1st Department of Ophthalmology, 'G. Gennimatas Hospital', National and Kapodistrian University of Athens, Athens, Greece
| | - Ilias Georgalas
- 1st Department of Ophthalmology, 'G. Gennimatas Hospital', National and Kapodistrian University of Athens, Athens, Greece
| | - George D Kymionis
- 1st Department of Ophthalmology, 'G. Gennimatas Hospital', National and Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
22
|
Technical Feasibility of Isolated Bowman Layer Graft Preparation by Femtosecond Laser: A Pilot Study. Eur J Ophthalmol 2017; 27:675-677. [DOI: 10.5301/ejo.5000990] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2017] [Indexed: 11/20/2022]
Abstract
Purpose To evaluate the technical feasibility of isolated Bowman layer (BL) graft preparation by femtosecond laser (FSL) and to compare the ultrastructural morphology to manually dissected grafts. Methods Five whole globes were placed in custom-made eye holders and debrided of epithelium. After programming a dissection depth of 20 μm, the FSL was docked into position and 5 isolated BL grafts were created. From 5 additional globes, corneoscleral buttons were procured, mounted in artificial anterior chambers, and stripped of BL via the previously described manual technique. Three specimens from both series were randomly selected and assigned to transmission electron microscopy for ultrastructural evaluation and thickness measurements. Results All dissections were uneventful and 10 total grafts were produced: 5 by FSL and 5 by manual dissection. Mean graft thickness was 37 (±8.6) μm (n = 3) for the FSL group and 11.7 (±1.6) μm (n = 3) for the manually dissected group. Transmission electron microscopy revealed a thick but relatively smooth posterior cut edge in the FSL group, versus a virtually isolated BL with irregular rests of dispersed stroma in the manually dissected group. Conclusions Femtosecond laser may have potential for harvesting intact BL and with a smooth posterior surface, but accompanied by variable amounts of anterior stroma owing to technical limitations.
Collapse
|
23
|
Parker J, van Dijk K, Melles G. Updates in anterior lamellar keratoplasty: the state of the debates. EXPERT REVIEW OF OPHTHALMOLOGY 2016. [DOI: 10.1080/17469899.2016.1224656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
24
|
Parker JS, van Dijk K, Melles GRJ. Treatment options for advanced keratoconus: A review. Surv Ophthalmol 2015; 60:459-80. [PMID: 26077628 DOI: 10.1016/j.survophthal.2015.02.004] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/17/2015] [Accepted: 02/20/2015] [Indexed: 10/23/2022]
Abstract
Traditionally, the mainstay of treatment for advanced keratoconus (KC) has been either penetrating or deep anterior lamellar keratoplasty (PK or DALK, respectively). The success of both operations, however, has been somewhat tempered by potential difficulties and complications, both intraoperatively and postoperatively. These include suture and wound-healing problems, progression of disease in the recipient rim, allograft reaction, and persistent irregular astigmatism. Taken together, these have been the inspiration for an ongoing search for less troublesome therapeutic alternatives. These include ultraviolet crosslinking and intracorneal ring segments, both of which were originally constrained in their indication exclusively to eyes with mild to moderate disease. More recently, Bowman layer transplantation has been introduced for reversing corneal ectasia in eyes with advanced KC, re-enabling comfortable contact lens wear and permitting PK and DALK to be postponed or avoided entirely. We offer a summary of the current and emerging treatment options for advanced KC, aiming to provide the corneal specialist useful information in selecting the optimal therapy for individual patients.
Collapse
Affiliation(s)
- Jack S Parker
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands; UAB Callahan Eye Hospital, Birmingham, Alabama, USA
| | - Korine van Dijk
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands
| | - Gerrit R J Melles
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands; Melles Cornea Clinic, Rotterdam, The Netherlands; Amnitrans EyeBank, Rotterdam, The Netherlands.
| |
Collapse
|
25
|
van Dijk K, Liarakos VS, Parker J, Ham L, Lie JT, Groeneveld-van Beek EA, Melles GRJ. Bowman layer transplantation to reduce and stabilize progressive, advanced keratoconus. Ophthalmology 2015; 122:909-17. [PMID: 25596620 DOI: 10.1016/j.ophtha.2014.12.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 12/03/2014] [Accepted: 12/07/2014] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE To evaluate the clinical outcome of mid-stromal isolated Bowman layer transplantation, a new surgical technique to reduce and stabilize ectasia in eyes with advanced keratoconus, to postpone penetrating keratoplasty or deep anterior lamellar keratoplasty, and to enable continued daily contact lens wear. DESIGN Prospective, nonrandomized cohort study at a tertiary referral center. PARTICIPANTS Twenty-two eyes of 19 patients with progressive, advanced keratoconus not eligible for ultraviolet cross-linking. INTERVENTIONS The mid-stroma was manually dissected and an isolated donor Bowman layer was positioned within the stromal pocket. MAIN OUTCOME MEASURES Before and up to 36 months after surgery (mean follow-up, 21±7 months), best spectacle-corrected visual acuity (BSCVA), best contact lens-corrected visual acuity (BCLVA), Scheimpflug-based corneal tomography measurements, endothelial cell density, biomicroscopy, refraction, and intraoperative and postoperative complications were recorded. RESULTS Two surgeries were complicated by an intraoperative perforation of Descemet membrane; no other intraoperative or postoperative complications were observed. Maximum keratometry decreased on average from 77.2±6.2 diopters (D) to 69.2±3.7 D (P < 0.001) at 1 month after surgery and remained stable thereafter (P ≥ 0.072). Mean BSCVA improved from 1.27±0.44 logarithm of the minimum angle of resolution units before surgery to 0.90±0.30 logarithm of the minimum angle of resolution units 12 months after surgery (P < 0.001), whereas BCLVA remained stable (P = 0.105). Mean thinnest-point pachymetry increased from 332±59 μm before surgery to 360±50 μm at the latest follow-up (P = 0.012), and no change in endothelial cell density was found (P = 0.355). CONCLUSIONS With isolated Bowman layer transplantation, reduction and stabilization of corneal ectasia was achieved in eyes with progressive, advanced keratoconus. Given the low risk for complications, the procedure may be performed to postpone penetrating or deep anterior lamellar keratoplasty.
Collapse
Affiliation(s)
- Korine van Dijk
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; Melles Cornea Clinic, Rotterdam, the Netherlands
| | - Vasilios S Liarakos
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; Melles Cornea Clinic, Rotterdam, the Netherlands
| | - Jack Parker
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; Melles Cornea Clinic, Rotterdam, the Netherlands; Callahan Eye Hospital, University of Alabama at Birmingham, Birmingham, Alabama
| | - Lisanne Ham
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; Melles Cornea Clinic, Rotterdam, the Netherlands; Amnitrans EyeBank, Rotterdam, the Netherlands
| | - Jessica T Lie
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; Amnitrans EyeBank, Rotterdam, the Netherlands
| | - Esther A Groeneveld-van Beek
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; Amnitrans EyeBank, Rotterdam, the Netherlands
| | - Gerrit R J Melles
- Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands; Melles Cornea Clinic, Rotterdam, the Netherlands; Amnitrans EyeBank, Rotterdam, the Netherlands.
| |
Collapse
|
26
|
Rocha G, Butler M, Butler A, Hackett JM. Femtosecond-UVA-riboflavin (FUR) cross-linking approach to penetrating keratoplasty and anterior lamellar keratoplasty. Saudi J Ophthalmol 2011; 25:261-7. [PMID: 23960934 DOI: 10.1016/j.sjopt.2011.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 04/22/2011] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To introduce femtosecond laser wound design combined with riboflavin/ultraviolet light-A (UVA) collagen cross-linking at the wound for penetrating (PKP) and anterior lamellar keratoplasty (ALK). Primary outcomes were intraocular pressure (IOP in mmHg) at burst point for the PKP group, and tensile strength (kPa) until dehiscence for the ALK group. METHODS Human corneoscleral rims (N = 20) were mounted on artificial anterior chambers. PKP specimens underwent FUR, femtosecond laser-cut without cross-linking, or conventional corneal transplantation. PKP maximum burst IOP with progressive suture removal was assessed by a digital manometer, in triplicate and by three observers. ALK involved whole human globes (N = 10) divided into three groups using a 200-micron, 8 mm diameter donor lenticule, with or without cross-linking. Cross-linked specimens were exposed to UVA light (3 mW/cm(2) irradiance, 3.4 J, 370 nm wavelength) for 30 min with 0.1% riboflavin (20% Dextran) applied every 2-min. ALK tensile strength was determined using a digital tensiometer. RESULTS In PKP, burst IOP was 31.32 mmHg greater for corneas that underwent the UVA-riboflavin treatment than for those that did not (p < 0.05). There was no significant relationship (p = 0.719) established between cut design (femtosecond versus conventional). On multivariate analysis, there was a mean of 15.82 mmHg higher sustainable pressure for each stabilization suture present (p < 0.0001). In ALK, specimens comprised of human donor and human recipient tissue combined with UVA-riboflavin therapy experienced the greatest level of adhesion strength (954.7 ± 290.4 kPa) as shown by the force required to separate the tissues, and compared to non-cross-linked specimens. Electron microscopy of ALK specimens showed non-fused and fused longitudinal cross-linked collagen fibers as well as bridges, densities, attachment plaques and primitive plasmalemmal densities. CONCLUSIONS Cross-linking effects of the FUR technique enable a stronger graft-recipient adhesion compared to conventional penetrating and anterior lamellar keratoplasty. Electron microscopy enabled visualization of cross-linked interface and potential bonding. The FUR approach may further lead to sutureless transplantation techniques in the future. SETTING/VENUE ImagePlus Laser Eye Centre, Winnipeg, and University of Ottawa Eye Institute, Ottawa, Canada.
Collapse
Affiliation(s)
- Guillermo Rocha
- GRMC Vision Centre, Image Plus Laser Eye Centre, University of Manitoba, Winnipeg, Manitoba, Canada ; Department of Ophthalmology, University of Ottawa Eye Institute, The Ottawa Hospital, Ottawa, Ontario, Canada
| | | | | | | |
Collapse
|
27
|
|
28
|
|