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Nishant P, Gurnani B, Singh P, Sinha S, Kaur K, Kumar A, Sinha RK. Current concepts and recent trends in endothelial keratoplasty. World J Transplant 2025; 15. [DOI: 10.5500/wjt.v15.i2.102507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2024] [Revised: 01/15/2025] [Accepted: 01/21/2025] [Indexed: 02/21/2025] Open
Abstract
Endothelial keratoplasty (EK) is defined as an umbrella term comprising methods for selective surgical replacement of corneal endothelium and adjacent corneal tissue, which retains healthy portions of a patient's cornea while replacing diseased innermost corneal layer(s) with healthy donor tissue, to achieve corneal dehydration and transparency before the onset of irreversible stromal edema and permanent loss of corneal clarity. Recently, the pathophysiology of corneal decompensation is increasingly being researched upon. Consequent improvement in pharmacotherapy is progressively leading to reduction in the indications of EK. In addition, EK techniques have progressed towards using thinner tissue, optimizing visual outcomes. Improvements have enabled better donor tissue formulation, usage, and attachment, and surgical modifications have enhanced the tissue utilization in difficult clinical scenarios lowering failure and rejection. However, challenges are encountered in various complex clinical scenarios including eyes with prior intraocular surgery, complex anterior chamber anatomy, glaucoma, ocular surface disease etc. These complexities demand tailored surgical strategies, including modifications in graft handling, instrumentation, and postoperative management to ensure success. Attention to these details and addressing patient-specific factors can help improve outcomes in these difficult cases. The choice of procedure depends on multiple factors, including the surgeon's experience, patient's ocular anatomy, and the specific clinical scenario. This review article encompasses the recent developments in this field presenting a comprehensive picture of our modern understanding of the indications, contraindications, surgical techniques, clinical situations, community aspects and future directions pertaining to EK.
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Affiliation(s)
- Prateek Nishant
- Department of Ophthalmology-Refractive Surgery, Uvea and Neuro-Ophthalmology, Akhand Jyoti Eye Hospital, Mastichak, Saran 841219, Bihar, India
| | - Bharat Gurnani
- Department of Cataract, Cornea, External Diseases, Trauma, Ocular Surface, Refractive Surgery and Contact Lens, Gomabai Netralaya and Research Center, Neemuch 458441, Madhya Pradesh, India
| | - Prabhakar Singh
- Department of Ophthalmology-Cornea and Ocular Surface, All India Institute of Medical Sciences, Kalyani 741245, West Bengal, India
| | - Sony Sinha
- Department of Ophthalmology-Vitreo-Retina, Neuro-Ophthalmology and Oculoplasty, All India Institute of Medical Sciences, Patna 801507, Bihar, India
| | - Kirandeep Kaur
- Department of Cataracts, Pediatric Ophthalmology and Strabismus, Gomabai Netralaya and Research Center, Neemuch 458441, Madhya Pradesh, India
| | - Ashish Kumar
- Department of Cornea and Refractive Surgery, Laxmi Netralaya, Jamal Road, Patna 800001, Bihar, India
| | - Ranjeet Kumar Sinha
- Department of Community Medicine, Patna Medical College, Patna 800004, Bihar, India
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Heger KA, Egger D, Schmidinger G, Skorpik C, Waldstein SM, Pircher N. A historical view of the development of corneal transplantation: from penetrating keratoplasty to selective transplantation of the finest corneal layers. Wien Med Wochenschr 2025; 175:175-185. [PMID: 40167948 DOI: 10.1007/s10354-025-01077-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2024] [Accepted: 02/13/2025] [Indexed: 04/02/2025]
Abstract
Replacement of damaged corneal tissue with a clear transplant represents a viable solution for restoring vision in patients with corneal blindness. Among organ transplants, corneal transplantation occupies a unique status due to the cornea's lack of vascularization. This avascular nature makes immune compatibility testing between donor and recipient unnecessary and reduces the risk of transplant rejection, making corneal transplantation the most successful organ transplant procedure worldwide. Over the past century, corneal transplantation has undergone a transformative journey, evolving from full-thickness keratoplasty to highly refined techniques that selectively target individual diseased corneal layers. These modern lamellar approaches aim for faster recovery times and reduced rejection rates. The global demand for corneal graft tissue far exceeds the availability of donor tissue, leading to prolonged waiting times for patients in need of transplantation. Modern therapeutic strategies are expected to support or potentially even replace transplantation of corneal layers in the future.
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Affiliation(s)
- Katharina A Heger
- Department of Ophthalmology, Landesklinikum Mistelbach-Gänserndorf, Liechtensteinstraße 67, 2130, Mistelbach, Austria
- Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Daniel Egger
- Department of Ophthalmology, Landesklinikum Mistelbach-Gänserndorf, Liechtensteinstraße 67, 2130, Mistelbach, Austria
- Karl Landsteiner University of Health Sciences, Krems, Austria
- Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Gerald Schmidinger
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Christian Skorpik
- Department of Ophthalmology, Landesklinikum Mistelbach-Gänserndorf, Liechtensteinstraße 67, 2130, Mistelbach, Austria
- Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Sebastian M Waldstein
- Department of Ophthalmology, Landesklinikum Mistelbach-Gänserndorf, Liechtensteinstraße 67, 2130, Mistelbach, Austria
- Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Niklas Pircher
- Department of Ophthalmology, Landesklinikum Mistelbach-Gänserndorf, Liechtensteinstraße 67, 2130, Mistelbach, Austria.
- Karl Landsteiner University of Health Sciences, Krems, Austria.
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Hoffmann JV, Betancor PK, Maier P, Lapp T, Heinzelmann S, Böhringer D, Lang S, Reinhard T. Changing indications for keratoplasty: monocentric analysis of the past two decades. Graefes Arch Clin Exp Ophthalmol 2025; 263:745-751. [PMID: 39297889 PMCID: PMC11953164 DOI: 10.1007/s00417-024-06639-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/31/2024] [Accepted: 09/05/2024] [Indexed: 09/21/2024] Open
Abstract
PURPOSE Over the past two decades, lamellar keratoplasty procedures, such as Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) and Descemet's Membrane Endothelial Keratoplasty (DMEK) as well as Deep Anterior Lamellar Keratoplasty (DALK), have become an integral part of clinical practice. With advances in contact lens fitting for keratoconus management and the implementation of UVA-Riboflavin Crosslinking (CXL), the landscape of keratoplasty indications is undergoing changes. Procedures and indications in a single tertiary care center over the past two decades are reviewed in this retrospective analysis. METHODS Retrospective analysis utilized anonymized electronic data from the LIONS cornea bank Baden-Württemberg, Eye Center Freiburg, spanning from beginning of 2004 to end of 2023. The primary focus was on surgical procedures and indications for keratoplasty. RESULTS The study encompassed a comprehensive analysis of 7130 corneal transplants. Penetrating keratoplasty (PK) exhibited a significant decline from 95% (n = 206, 2004) to 11% (n = 46, 2023), while DMEK increased from 48% (n = 157, 2012) to 82% (n = 347, 2023). Fuchs endothelial dystrophy (FED) emerged as the dominant indication, witnessing a significant increase from 24% (2004, n = 39) to 72% (2023, n = 288). Conversely, keratoconus (KC) showed a reciprocal change from 25% (2004, n = 40) to 4% (2023, n = 17). PK demonstrated a noteworthy indication shift in descending order from Bullous Keratopathy (BK), FED, and KC in 2004 to KC, graft failure, corneal scars, and ulcers in 2023. Repeat keratoplasty following DMEK remained rare, but a discernible upward trend was observed for PK. CONCLUSION This retrospective analysis highlights significant changes in both keratoplasty indications and techniques over the past two decades. DMEK has emerged as a successful intervention for treating endothelial diseases, while PK retains its qualitative indispensability for a wide range of indications. Modern corneal banks are urged to maintain a robust supply of grafts for all surgical techniques in anticipation of potential increased demand in the future, particularly for repeat keratoplasties. KEY MESSAGES What is known • Over the past two decades, lamellar keratoplasty procedures such as DSAEK and DMEK have increasingly replaced penetrating keratoplasty (PK) in clinical practice due to their improved outcomes and reduced complications for certain indications. New Findings • Our study reveals a significant shift in keratoplasty indications, with Fuchs endothelial dystrophy (FED) emerging as the predominant indication, increasing from 24% in 2004 to 72% in 2023, while keratoconus (KC) declined from 25 to 4% during the same period. • Penetrating keratoplasty (PK) has shown a marked decline in use, dropping from 95% of keratoplasties in 2004 to 11% in 2023, whereas DMEK has grown to represent 82% of procedures in 2023. • Despite the rise of DMEK, PK remains vital for a broad spectrum of indications, highlighting the necessity for corneal banks to maintain a versatile supply of grafts to meet diverse clinical needs, particularly in cases of repeat keratoplasties.
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Affiliation(s)
- Jan Vincent Hoffmann
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany.
| | - Paola Kammrath Betancor
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany
| | - Philip Maier
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany
| | - Thabo Lapp
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany
- Department of Ophthalmology, St. Franziskus Hospital, Muenster, Germany
| | - Sonja Heinzelmann
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany
| | - Daniel Böhringer
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany
| | - Stefan Lang
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany
- Department of Ophthalmology, Brandenburg Medical School, University Hospital Brandenburg, Brandenburg an Der Havel, Germany
| | - Thomas Reinhard
- Eye Center, Medical Center, University Freiburg, Killianstraße 5, 79106, Freiburg im Breisgau, Germany
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Zwingelberg SB, Karabiyik G, Gehle P, von Brandenstein M, Eibichova S, Lotz C, Groeber-Becker F, Kampik D, Jurkunas U, Geerling G, Lang G. Advancements in bioengineering for descemet membrane endothelial keratoplasty (DMEK). NPJ Regen Med 2025; 10:10. [PMID: 39952985 PMCID: PMC11828897 DOI: 10.1038/s41536-025-00396-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Accepted: 01/27/2025] [Indexed: 02/17/2025] Open
Abstract
Corneal diseases are the third leading cause of blindness worldwide. Descemet's Membrane Endothelial Keratoplasty (DMEK) is the preferred surgical technique for treating corneal endothelial disorders, relying heavily on high-quality donor tissue. However, the scarcity of suitable donor tissue and the sensitivity of endothelial cells remain significant challenges. This review explores the current state of DMEK, focusing on advancements in tissue engineering as a promising solution to improve outcomes and address donor limitations.
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Affiliation(s)
| | - Gizem Karabiyik
- Department of Functional Materials in Medicine and Dentistry, University Hospital Würzburg, Würzburg, Germany
| | - Paul Gehle
- Department of Urology, University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Melanie von Brandenstein
- Department of Urology, University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Sabina Eibichova
- University Hospital Würzburg, Department of Tissue Engineering and Regenerative Medicine, Würzburg, Germany
| | - Christian Lotz
- University Hospital Würzburg, Department of Tissue Engineering and Regenerative Medicine, Würzburg, Germany
- Fraunhofer Institute for Silicate Research ISC Translational Center Regenerative Therapies, Würzburg, Germany
| | - Florian Groeber-Becker
- Department of Ophthalmology, University Hospital of Duesseldorf, Duesseldorf, Germany
- Fraunhofer Institute for Silicate Research ISC Translational Center Regenerative Therapies, Würzburg, Germany
| | - Daniel Kampik
- Department of Ophthalmology, University Hospital Würzburg, Würzburg, Germany
| | - Ula Jurkunas
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Institute, Boston, MA, USA
| | - Gerd Geerling
- Department of Ophthalmology, University Hospital of Duesseldorf, Duesseldorf, Germany
| | - Gregor Lang
- Department of Functional Materials in Medicine and Dentistry, University Hospital Würzburg, Würzburg, Germany.
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Mali R, Priyadarshini SR, Sahu SK, Mohanty A, Das S. Microkeratome versus manually dissected donor tissue for Descemet stripping endothelial keratoplasty: A randomized prospective study. Indian J Ophthalmol 2024; 72:1728-1733. [PMID: 38990636 PMCID: PMC11727928 DOI: 10.4103/ijo.ijo_3282_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: 12/15/2023] [Revised: 04/19/2024] [Accepted: 05/06/2024] [Indexed: 07/12/2024] Open
Abstract
PURPOSE To compare the visual outcomes, postoperative complications, and graft asymmetry between precut and manually dissected donor tissues for Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet stripping endothelial keratoplasty (DSEK) procedures, respectively. METHODS Seventy eyes of 70 patients undergoing DSEK/DSAEK at a tertiary eyecare center in eastern India were included in this prospective randomized control study. The 70 eyes were divided equally into two groups. Group A ( n = 35) and Group B ( n = 35) underwent DSEK and DSAEK procedures, respectively. the operating surgeons prepared the manually dissected corneal grafts using lamellar dissectors. the eye bank technicians prepared the precut corneal grafts using a microkeratome. The patients were investigated postoperatively after 1 day, 1 week, 1 month, 3 months, and 6 months. The data were compared for visual outcomes [uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical and cylindrical refraction, and spherical equivalent], incidence of postoperative complications, and pachymetry. RESULTS The mean age was 56.5 (±17.8) years, and the male-to-female ratio was 1.3:1. The most common indications were pseudophakic bullous keratopathy (45.71%, 32/70), failed graft (32.86%, 23/70), and Fuchs' endothelial corneal dystrophy (10%, 7/70). The indications for surgery ( P = 0.732) and donor ( P = 0.258) and host pachymetry ( P = 0.986) were comparable between both groups. There was no significant difference in change of UCVA, BCVA, and postoperative refraction (mean spherical refraction, P = 0.849; mean cylindrical refraction, P = 0.516; spherical equivalent, P = 0.518) between the two groups. Postoperative complications like graft detachment ( P = 0.179), graft failure ( P = 0.513), graft infiltrate ( P = 0.428), and endophthalmitis ( P = 0.493) were higher in the DSAEK group; however, the difference between the groups was insignificant. The graft asymmetry index was higher in DSAEK than in DSEK; the difference was significant till the 1-month follow-up ( P = 0.005). CONCLUSION The outcome was similar in both groups. Therefore, manual donor dissection can be an alternative for microkeratome-assisted dissection in low-resource centers and countries to achieve good results.
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Affiliation(s)
- Ritu Mali
- Cornea and Anterior Segment Service, L. V. Prasad Eye Institute, Bhubaneswar, Odisha, India
| | | | - Srikant K. Sahu
- Cornea and Anterior Segment Service, L. V. Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Amrita Mohanty
- Cornea and Anterior Segment Service, L. V. Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Sujata Das
- Cornea and Anterior Segment Service, L. V. Prasad Eye Institute, Bhubaneswar, Odisha, India
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Gheorghe AG, Onofrei AG, Arghirescu AM, Coleașă A, Tiran GD, Dinu LI, Toader EV. Strategic Management of Descemet's Membrane Perforation During DALK in Advanced Keratoconus. Rom J Ophthalmol 2024; 68:448-456. [PMID: 39936068 PMCID: PMC11809823 DOI: 10.22336/rjo.2024.81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2024] [Indexed: 02/13/2025] Open
Abstract
Objective To report on the surgical treatment of advanced keratoconus (KC) with stromal scarring in a young male patient with asymmetric disease progression complicated by an intraoperative microperforation of Descemet's membrane (DM) during deep anterior lamellar keratoplasty (DALK). Methods The surgical approach consisted of manual descemetic DALK (dDALK), further complicated with DM microperforation. Anterior segment ocular coherence tomography (AS-OCT) was used intraoperatively to locate the site and size of the tear. The surgeon decided not to convert to penetrating keratoplasty (PK), despite stromal scarring, significant ectasia, and variable corneal thickness, but rather to continue the dissection of the stromal bed with maximum precaution. Results Postoperatively, visual results improved and reached the best corrected visual acuity of 20/20. Choosing a proper graft dimension and reaching anatomical separation up to the DM were the keys to obtaining such a positive refractive outcome. Discussions DALK, the most advanced treatment for KC, was chosen as the ideal option for this young patient due to its advantages over PK: reduced rejection risk, fewer complications, quicker steroid tapering, and faster recovery. However, its steep learning curve remains a challenge for surgeons. Conclusions Despite manual DALK being a more challenging and time-consuming procedure than PK, careful dissection of the stromal bed and diligent assessment of the affected DM can provide a better and safer outcome for selected patients. Even if initial postoperative visual results are impressive, the surgeon must pay attention to the patient's future check-ups to swiftly correct any possible complications.
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Affiliation(s)
- Alina Gabriela Gheorghe
- “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
- Department of Ophthalmology, Clinical Hospital for Ophthalmological Emergencies Bucharest, Bucharest, Romania
| | - Ancuța Georgiana Onofrei
- “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
- Department of Ophthalmology, Clinical Hospital for Ophthalmological Emergencies Bucharest, Bucharest, Romania
| | - Ana-Maria Arghirescu
- “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
- Department of Ophthalmology, Clinical Hospital for Ophthalmological Emergencies Bucharest, Bucharest, Romania
| | - Andrei Coleașă
- Department of Ophthalmology, Clinical Hospital for Ophthalmological Emergencies Bucharest, Bucharest, Romania
| | - Georgia-Denisa Tiran
- Department of Ophthalmology, Clinical Hospital for Ophthalmological Emergencies Bucharest, Bucharest, Romania
| | - Laura Ioana Dinu
- Department of Ophthalmology, Clinical Hospital for Ophthalmological Emergencies Bucharest, Bucharest, Romania
| | - Elena Veronica Toader
- Department of Ophthalmology, Clinical Hospital for Ophthalmological Emergencies Bucharest, Bucharest, Romania
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Samarawickrama C. Novel Trephine for Descemet Membrane Endothelial Keratoplasty Surgery Improves Surgical Preparation Time and Graft Quality: Pilot Data From the "Number 7" Endothelial Keratoplasty Trephine. Cornea 2024:00003226-990000000-00682. [PMID: 39264752 DOI: 10.1097/ico.0000000000003700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Accepted: 08/06/2024] [Indexed: 09/14/2024]
Abstract
PURPOSE To report the safety and efficacy of a novel asymmetric marking trephine for Descemet membrane endothelial keratoplasty (DMEK) tissue preparation. The trephine design incorporates optimized curves to distribute mechanical forces and minimize the risk of tears without loss of total endothelial cell volume transplanted compared with a standard 8.00 mm circular transplant. METHODS A retrospective case series of 40 consecutive DMEK operations comparing 20 cases using the "Number 7" trephine against 20 using a modified shark fin technique as standard. Patient and donor characteristics, tissue preparation time and complications, total surgical time, intraoperative and postoperative complications, and endothelial cell counts at 3 months postsurgery are reported. RESULTS DMEK tissue preparation was significantly faster using the "Number 7" trephine (5.4 vs. 7.6 minutes, P = 0.008). Further, fewer complications arose during tissue preparation (0 vs. 2 complications) despite the faster preparation time. Total surgical time was similar between techniques; however, time spent manipulating the graft was reduced (5.1 vs. 6.8 minutes, P = 0.007) primarily because of the lower tissue preparation complications. Fewer postoperative complications were observed (1 vs. 3, of which 1 in the standard technique group requiring a redo-DMEK), again due to the reduced tissue preparation complications. The 3-month endothelial cell count was comparable between techniques (P > 0.05). CONCLUSIONS Use of the "Number 7" trephine led to faster and safer DMEK tissue preparation, which in turn reduced graft manipulation times and postoperative complications without compromising total endothelial cell volume transplanted. This novel device is ideal for use by surgeons who prepare their own DMEK tissue and within tissue banks who provide prestripped and preloaded DMEK tissue.
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Affiliation(s)
- Chameen Samarawickrama
- Faculty of Medicine and Health, Clinical Ophthalmology and Eye Health, Westmead Institute for Medical Research (WIMR), Save Sight Institute, Westmead and Central Clinical Schools, The University of Sydney, Sydney, Australia
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Kijonka M, Nowińska A, Wylęgała E, Wylęgała A, Wróblewska-Czajka E, Kryszan K, Dugiełło B, Orzechowska-Wylęgała B. Postoperative Astigmatism after Keratoplasty: A Systematic Review Meta-Analysis Based on PRISMA. J Clin Med 2024; 13:3306. [PMID: 38893017 PMCID: PMC11172787 DOI: 10.3390/jcm13113306] [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: 04/25/2024] [Revised: 05/22/2024] [Accepted: 05/27/2024] [Indexed: 06/21/2024] Open
Abstract
Background: The number of corneal transplants is rising, with the aim to treat a spectrum of diseases ranging from dystrophies to corneal opacities caused by trauma or chemical burns. Refractive outcomes after this procedure are often impossible to predict and associated with high levels of astigmatism. However, there are many techniques that affect the reduction of astigmatism and improve the quality of life of patients. Objectives: The aim was to compare the improvement in postoperative visual acuity (logMAR) and amount of corneal astigmatism (Diopters) after corneal keratoplasty in patients who additionally underwent a surgical procedure, which affects the reduction in postoperative astigmatism, and to determine the most effective method. Search Methods and Selection Criteria: A thorough search was carried out across online electronic databases including PubMed, Embrase, Ovid MEDLINE, Scopus, and Web of Science, using combinations containing the following phrases: postoperative astigmatism, post-keratoplasty astigmatism, anterior lamellar keratoplasty (ALK), deep anterior lamellar keratoplasty (DALK), posterior lamellar keratoplasty, endothelial keratoplasty (EK), penetrating keratoplasty (PK), corneal transplant, keratoplasty, refractive surgery, kerato-refractive surgery, laser in situ keratomileusis (LASIK), and femtosecond LASIK. This was to determine all English-language publications that discuss refractive operations for postoperative or post-keratoplasty astigmatism. These bibliographies were searched for English-language publications published between 2010 and 2023. We proceeded to review each detected record's reference list. Data Extraction: Study characteristics such as study design, sample size, participant information, operations performed, and clinical outcomes were all extracted. Data Statistical Analyses: The Comprehensive Meta-Analysis software (version 3.3.070, 2014) was used to perform the analysis. The threshold of 0.05 for p-values was considered statistically significant. All effect sizes are reported as standardized differences (Std diff) in means with a 95% confidence interval (CI) and visualized graphically as forest plots. Publication bias is presented as a funnel plot of standard error by Std diff in means. Four methods were used to evaluate the heterogeneity among the studies: Q-value, I2, chi-square (χ2), and tau-squared. Main Results: We included 21 studies that randomized 1539 eyes that underwent corneal transplantation surgery either by PKP, DALK, or DSEAK techniques. The results showed the most significant improvement in the visual acuity and significant decrease in the corneal astigmatism after laser surgery procedures, like femtosecond-assisted keratotomy after DALK and PKP and LASIK after DSEAK.
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Affiliation(s)
- Magdalena Kijonka
- Chair and Clinical Department of Ophthalmology, School of Medicine in Zabrze, Medical University of Silesia in Katowice, District Railway Hospital, 40-760 Katowice, Poland; (A.N.); (E.W.); (A.W.); (E.W.-C.); (K.K.); (B.D.)
- Department of Ophthalmology, District Railway Hospital in Katowice, 40-760 Katowice, Poland
| | - Anna Nowińska
- Chair and Clinical Department of Ophthalmology, School of Medicine in Zabrze, Medical University of Silesia in Katowice, District Railway Hospital, 40-760 Katowice, Poland; (A.N.); (E.W.); (A.W.); (E.W.-C.); (K.K.); (B.D.)
- Department of Ophthalmology, District Railway Hospital in Katowice, 40-760 Katowice, Poland
| | - Edward Wylęgała
- Chair and Clinical Department of Ophthalmology, School of Medicine in Zabrze, Medical University of Silesia in Katowice, District Railway Hospital, 40-760 Katowice, Poland; (A.N.); (E.W.); (A.W.); (E.W.-C.); (K.K.); (B.D.)
- Department of Ophthalmology, District Railway Hospital in Katowice, 40-760 Katowice, Poland
| | - Adam Wylęgała
- Chair and Clinical Department of Ophthalmology, School of Medicine in Zabrze, Medical University of Silesia in Katowice, District Railway Hospital, 40-760 Katowice, Poland; (A.N.); (E.W.); (A.W.); (E.W.-C.); (K.K.); (B.D.)
- Department of Ophthalmology, District Railway Hospital in Katowice, 40-760 Katowice, Poland
- Health Promotion and Obesity Management, Pathophysiology Department, Medical University of Silesia in Katowice, 40-752 Katowice, Poland
| | - Ewa Wróblewska-Czajka
- Chair and Clinical Department of Ophthalmology, School of Medicine in Zabrze, Medical University of Silesia in Katowice, District Railway Hospital, 40-760 Katowice, Poland; (A.N.); (E.W.); (A.W.); (E.W.-C.); (K.K.); (B.D.)
- Department of Ophthalmology, District Railway Hospital in Katowice, 40-760 Katowice, Poland
| | - Katarzyna Kryszan
- Chair and Clinical Department of Ophthalmology, School of Medicine in Zabrze, Medical University of Silesia in Katowice, District Railway Hospital, 40-760 Katowice, Poland; (A.N.); (E.W.); (A.W.); (E.W.-C.); (K.K.); (B.D.)
- Department of Ophthalmology, District Railway Hospital in Katowice, 40-760 Katowice, Poland
| | - Bogdan Dugiełło
- Chair and Clinical Department of Ophthalmology, School of Medicine in Zabrze, Medical University of Silesia in Katowice, District Railway Hospital, 40-760 Katowice, Poland; (A.N.); (E.W.); (A.W.); (E.W.-C.); (K.K.); (B.D.)
- Department of Ophthalmology, District Railway Hospital in Katowice, 40-760 Katowice, Poland
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Tjoa K, Nadhif MH, Utami SS, Kusuma SR, Astagiri PY, Adriono GA. Mechanical, optical, chemical, and biological evaluations of fish scale-derived scaffold for corneal replacements: A systematic review. Int J Biol Macromol 2024; 267:131183. [PMID: 38580016 DOI: 10.1016/j.ijbiomac.2024.131183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/03/2024] [Accepted: 03/26/2024] [Indexed: 04/07/2024]
Abstract
Corneal blindness is commonly treated through corneal replacement with allogeneic corneal donors, which may face shortage. Regarding this issue, xenogeneic alternatives are explored. Fish scale-derived scaffolds (FSSs) are among the alternatives due to the lower risk of infection and abundant sources of raw materials. Unfortunately, the information about mechanical, optical, chemical, and biological performances of FSSs for corneal replacements is still scattered, as well as about the fabrication techniques. This study aims to gather scattered pieces of information about the mentioned performances and fabrication techniques of FSSs for corneal replacements. Sorted from four scientific databases and using the PRISMA checklist, eleven relevant articles are collected. FSSs are commonly fabricated using decellularization and decalcification processes, generating FSSs with parallel multilayers or crossed fibers with topographic microchannels. In the collected studies, similar mechanical properties of FSSs to native tissues are discovered, as well as good transparency, light remittance, but poorer refractive indexes than native tissues. Biological evaluations mostly discuss histology, cell proliferations, and immune responses on FSSs, while only a few studies examine the vascularization. No studies completed comprehensive evaluations on the four properties. The current progress of FSS developments demonstrates the potential of FSS use for corneal replacements.
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Affiliation(s)
- Kevin Tjoa
- Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Muhammad Hanif Nadhif
- Botnar Research Centre, University of Oxford, Oxford, United Kingdom; Department of Medical Physiology and Biophysics, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia; Medical Technology Cluster, Indonesian Medical Education and Research Institute, Jakarta, Indonesia.
| | | | | | - Prasandhya Yusuf Astagiri
- Department of Medical Physiology and Biophysics, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia; Medical Technology Cluster, Indonesian Medical Education and Research Institute, Jakarta, Indonesia
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10
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Bonato P, Bagno A. Replace or Regenerate? Diverse Approaches to Biomaterials for Treating Corneal Lesions. Biomimetics (Basel) 2024; 9:202. [PMID: 38667213 PMCID: PMC11047895 DOI: 10.3390/biomimetics9040202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
The inner structures of the eye are protected by the cornea, which is a transparent membrane exposed to the external environment and subjected to the risk of lesions and diseases, sometimes resulting in impaired vision and blindness. Several eye pathologies can be treated with a keratoplasty, a surgical procedure aimed at replacing the cornea with tissues from human donors. Even though the success rate is high (up to 90% for the first graft in low-risk patients at 5-year follow-up), this approach is limited by the insufficient number of donors and several clinically relevant drawbacks. Alternatively, keratoprosthesis can be applied in an attempt to restore minimal functions of the cornea: For this reason, it is used only for high-risk patients. Recently, many biomaterials of both natural and synthetic origin have been developed as corneal substitutes to restore and replace diseased or injured corneas in low-risk patients. After illustrating the traditional clinical approaches, the present paper aims to review the most innovative solutions that have been recently proposed to regenerate the cornea, avoiding the use of donor tissues. Finally, innovative approaches to biological tissue 3D printing and xenotransplantation will be mentioned.
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Affiliation(s)
| | - Andrea Bagno
- Department of Industrial Engineering, University of Padua, 35131 Padua, Italy
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11
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Kaur A, Parida P, Priyadarshini SR, Mohanty A, Sahu SK, Das S. Indications and types of keratoplasties: Trends in the past 10 years (2011-2020) in Eastern India. Indian J Ophthalmol 2023; 71:3166-3170. [PMID: 37602603 PMCID: PMC10565916 DOI: 10.4103/ijo.ijo_2636_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 06/24/2023] [Accepted: 07/04/2023] [Indexed: 08/22/2023] Open
Abstract
Purpose To observe the trends of various types of keratoplasties in different etiologies over a period of 10 years (2011-2020) in a tertiary eye care center of eastern India. Methods A retrospective review of patients undergoing keratoplasties from 2011 to 2020 was performed in a tertiary eye care hospital situated in eastern part of India. Apart from demographic data, primary indication for each surgery and type of procedure carried out was recorded. For comparison, data were divided into two time periods: Group I: Jan 2011 to Dec 2015 and Group II: Jan 2016 to Dec 2020. Results Over a period of 10 years, a total of 2365 (Group I: 902, Group II: 1463) keratoplasties were performed. The average age of patients was 45.8 ± 19.9 and 46.9 ± 20.9 years in Group I and Group II, respectively. Among all the corneal grafts, 1747 (74%) surgeries were full-thickness. Although optical penetrating keratoplasty (OPK) was most the common indication for full-thickness keratoplasties, Descemet's stripping endothelial keratoplasty (DSEK) remained most performed lamellar keratoplasty. Keratitis, corneal scars, and bullous keratopathies remain to be most common indications in both groups. Number of lamellar keratoplasties increased significantly from Group I to Group II for corneal scars (P = 0.02), bullous keratopathies (P = 0.01), and endothelial dystrophies (P = 0.00). Conclusion With change in time, the indication and technique of keratoplasty has witnessed a changing trend from full-thickness keratoplasty to lamellar keratoplasty. There is rise in trend of lamellar keratoplasties over the period.
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Affiliation(s)
- Amanjot Kaur
- Cornea and Anterior Segment Service, L V Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Priyadarsani Parida
- Cornea and Anterior Segment Service, L V Prasad Eye Institute, Bhubaneswar, Odisha, India
| | | | - Amrita Mohanty
- Cornea and Anterior Segment Service, L V Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Srikant K Sahu
- Cornea and Anterior Segment Service, L V Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Sujata Das
- Cornea and Anterior Segment Service, L V Prasad Eye Institute, Bhubaneswar, Odisha, India
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12
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Pedrotti E, Bonacci E, Fasolo A, De Rossi A, Camposampiero D, Jones GLA, Bernardi P, Merigo F, Ponzin D, Marchini G, Sbarbati A. Ultrastructural Analysis of Rehydrated Human Donor Corneas After Air-Drying and Dissection by Femtosecond Laser. Front Med (Lausanne) 2022; 8:787937. [PMID: 34993214 PMCID: PMC8724048 DOI: 10.3389/fmed.2021.787937] [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: 10/01/2021] [Accepted: 11/24/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose: To evaluate the efficiency of femtosecond laser (FSL) incision of rehydrated human donor corneas after air-drying and its effects on corneal structure. Methods: We compared the rehydrated and fresh-preserved corneas by microscopy following Victus-Tecnolas FSL treatment for straight-edge anterior lamellar keratoplasty (ALK). The corneas were dehydrated at room temperature under a laminar-flow hood. Results: To obtain the horizontal cut in rehydrated corneas, we increased the FSL pulse energy to 1.2 μJ from 0.80 μJ applied for the fresh corneas and obtained a clear-cut separation of the lamellar lenticule cap from the corneal bed. Light microscopy showed regular arrangement of stromal collagen lamellae, with spaces in between the fibers in the corneal stroma in the fresh and the rehydrated corneas, but the uppermost epithelial layers in the rehydrated corneas were lost. Transmission electron microscopy (TEM) revealed no signs of thermal or mechanical damage to the corneal structure. The epithelial basal membrane and Bowman's layer maintained their integrity. The epithelial basal layer and cells were separated by large spaces due to junction alteration in the rehydrated corneas. There were gaps between the lamellar layers in the stroma, especially in the rehydrated corneas. Keratocytes displayed normal structure in the fresh corneas but were devoid of microorganules in the rehydrated corneas. Minor irregularities were observed in the vertical incision and the horizontal stroma appeared smooth on scanning electron microscopy. Conclusion: The corneal stroma of rehydrated corneas maintained morphology and integrity, while corneal cellular components were generally altered. When corneas are intended for FSL-assisted ALK, effective stromal bed incision is best achieved at a laser power higher than that currently adopted for fresh corneas.
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Affiliation(s)
- Emilio Pedrotti
- Ophthalmology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Erika Bonacci
- Ophthalmology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Adriano Fasolo
- Ophthalmology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,Research Unit, The Veneto Eye Bank Foundation, Venice, Italy
| | - Arianna De Rossi
- Ophthalmology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | - Gary L A Jones
- Research Unit, The Veneto Eye Bank Foundation, Venice, Italy
| | - Paolo Bernardi
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Flavia Merigo
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Diego Ponzin
- Research Unit, The Veneto Eye Bank Foundation, Venice, Italy
| | - Giorgio Marchini
- Ophthalmology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Andrea Sbarbati
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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Au SCL, Ko CKL. The Bubble Eye Sign: Understanding the Radiological Imaging of Gas inside the Orbit. Indian J Radiol Imaging 2021; 31:451-453. [PMID: 34556930 PMCID: PMC8448249 DOI: 10.1055/s-0041-1734359] [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] [Indexed: 11/25/2022] Open
Abstract
Gas, appears as radiolucent on X-ray, is normally absent in the orbit. However, intraocular surgeries occasionally utilize retained intraocular gas for tamponade effect. Intravitreal gas persists after retinal surgery, being confounded by the scleral shell of the operated eye, outlines the shape of the eyeball, and gives the characteristic bubble appearance on skull X-ray. This is different from orbital emphysema caused by orbital fracture when gas is located outside the globe but confined by the orbit, giving a crescent or concave shape over the superior orbit usually. Falls is common after intraocular retinal surgeries due to change of usual stereopsis, prolonged prone posturing, and other systemic comorbidities. By identifying the “Bubble Eye sign” described, attending physician should alert the presence of intravitreal gas, most commonly iatrogenic. Further ophthalmological history taking and examinations are thus indicated, instead of exposing patients to unnecessary radiation under computed tomography scan for orbital fracture investigation.
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Affiliation(s)
- Sunny C L Au
- Department of Ophthalmology, Memorial Ophthalmic Centre, Tung Wah Eastern Hospital, Hong Kong
| | - Callie K L Ko
- Department of Ophthalmology, Memorial Ophthalmic Centre, Tung Wah Eastern Hospital, Hong Kong
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14
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Corneal transillumination: technique to detect big bubble in deep anterior lamellar keratoplasty. J Cataract Refract Surg 2021; 47:671-673. [PMID: 32769750 DOI: 10.1097/j.jcrs.0000000000000369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/22/2020] [Indexed: 11/27/2022]
Abstract
Deep anterior lamellar keratoplasty is a widely adopted technique to treat pathologies of the cornea without endothelial cell involvement. This technique has several advantages including longer graft survival without endothelial rejection and lower doses of steroid administration. A transillumination technique was used to diagnose big bubble formation. A partial-thickness trephination was made, followed by superficial keratectomy and air injection into the stroma. Then, a vitreoretinal endoilluminator was used to illuminate the cornea and check for any signs of "full moon" or "waning moon," which corresponded to the shine of the big bubble from total internal reflection of light. Once the diagnosis was made, the remnant stroma was removed, and the donor cornea without endothelium was sutured. An advantage of this technique was that it allowed the diagnosis of big bubble even on an opaque or whitish emphysematous cornea when other methods could not be used.
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15
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Comparison of Long-Term Outcomes of the Lamellar and Penetrating Keratoplasty Approaches in Patients with Keratoconus. J Clin Med 2021; 10:jcm10112421. [PMID: 34072608 PMCID: PMC8199119 DOI: 10.3390/jcm10112421] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 12/15/2022] Open
Abstract
We compared the visual and refractive outcomes, intraocular pressure (IOP), endothelial cell loss (ECL), and adverse events in keratoconus patients after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) with the best corrected visual acuity (BCVA) below 0.3 (logMAR 0.52). This is a prospective, comparative cohort study of 90 eyes (90 patients) with a clinical diagnosis of keratoconus. Patients underwent a complete eye examination before the surgical approach, 6 and 12 months postoperatively that consisted of BCVA, refractive astigmatism (AS), central corneal thickness (CCT), IOP, and ECL. Secondary outcomes were adverse events related to the surgical procedure. With lower ECL and less adverse events, DALK was revealed to be beneficial over PK with similar visual outcomes. Results: There was no significant difference between the BCVA in the DALK and PK groups (at 6 months: 0.49 ± 0.17 vs. 0.48 ± 0.17; p = 0.48; at 12 months: 0.54 ± 0.17 vs. 0.52 ± 0.14; p = 0.41). The mean value of AS was significantly lower after the PK procedure when compared to DALK, after both 6 and 12 months of follow up (p < 0.001). The CCT in the DALK group was significantly lower when compared to the PK group (at 6 months: 452.1 ± 89.1 µm vs. 528.9 ± 69.9 µm, p < 0.0001; at 12 months: 451.6 ± 83.5 µm vs. 525.5 ± 37.1 µm). The endothelial cell loss at 12 months after surgery was significantly lower after DALK when compared to PK (p < 0.0001). DALK transplantation should be considered as an alternative procedure in the surgical treatment of keratoconus.
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16
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Manual DALK in Keratoconus: An Ex Vivo Light and Transmission Electron Microscopy Analysis 2 Years After Surgery. Cornea 2021; 41:370-373. [PMID: 34038068 DOI: 10.1097/ico.0000000000002752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/13/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to evaluate the microscopic structure of a human cornea 2 years after manual deep anterior lamellar keratoplasty (DALK) for keratoconus with a recipient residual stromal bed thickness of 100 μm, using light and transmission electron microscopy. METHODS A human cornea treated with manual DALK for keratoconus 2 years before was removed during penetrating keratoplasty because of stromal opacity of unknown origin, involving about half of the sample. The transparent half of the specimen was processed for light and transmission electron microscopy. RESULTS Light microscopy examination performed with different staining techniques (hematoxylin and eosin, Picrosirius red, and Masson trichrome) revealed a homogeneous stroma. No interface was detected. Electron microscopy confirmed these findings. CONCLUSIONS This study confirmed the available clinical and confocal studies that show progressive stromal remodeling after manual DALK. Two years after surgery, no posterior stromal interface was detected.
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17
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Sabater-Cruz N, Figueras-Roca M, Padró-Pitarch L, Tort J, Casaroli-Marano RP. Corneal transplantation activity in Catalonia, Spain, from 2011 to 2018: Evolution of indications and surgical techniques. PLoS One 2021; 16:e0249946. [PMID: 33831081 PMCID: PMC8031423 DOI: 10.1371/journal.pone.0249946] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 03/26/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To report corneal transplant activity carried out in Catalonia (Spain) and the evolving indications for keratoplasty over an 8-year period. Methods Annual reports from the Catalan Transplant Organization, Spain, on corneal graft indications and techniques from 2011 to 2018 were reviewed. Results A total of 9457 keratoplasties were performed in Catalonia, from January 2011 to December 2018. The most frequent indications were bullous keratopathy (BK; 20.5%), Fuchs endothelial dystrophy (FED; 17.9%), re-graft (13.7%), and keratoconus (11.3%). Penetrating keratoplasty (PKP) accounted for 63.4% of all performed keratoplasties. Since the introduction of eye bank precut tissue for Descemet stripping automated endothelial keratoplasty (DSAEK) in 2013 and for Descemet membrane endothelial keratoplasty (DMEK) in 2017 the number of endothelial keratoplasties has drastically increased. An increasing trend of posterior lamellar techniques over the total of keratoplasties was found (p<0.001). Endothelial keratoplasties for different endothelial diseases indications (BK, FED, and re-graft), also showed and increasing trend (p<0.001). DMEK is the technique with the highest increase (statistically significantly different from linearity) over other endothelial keratoplasties in FED (p<0.001) but not in BK (p = 0.67) or re-grafts (p = 0.067). Conclusion Endothelial diseases represented the top indication for keratoplasty over the 8-year period. PKP is still the most used technique in Catalonia, but endothelial keratoplasties and especially DMEK showed a significant increasing trend over the last years. This is congruent with the main rationale nowadays for keratoplasties: to customize and transplant as less tissue as possible. Therefore, the availability of precut tissue could have definitely enforced such approach.
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Affiliation(s)
- Noelia Sabater-Cruz
- Institut Clinic d’Oftalmologia (ICOF), Hospital Clinic de Barcelona, Barcelona, Spain
- * E-mail:
| | - Marc Figueras-Roca
- Institut Clinic d’Oftalmologia (ICOF), Hospital Clinic de Barcelona, Barcelona, Spain
| | - Lydia Padró-Pitarch
- Catalan Transplant Organization (Organització Catalana de Trasplantaments—OCATT), Barcelona, Spain
| | - Jaume Tort
- Catalan Transplant Organization (Organització Catalana de Trasplantaments—OCATT), Barcelona, Spain
| | - Ricardo P. Casaroli-Marano
- Institut Clinic d’Oftalmologia (ICOF), Hospital Clinic de Barcelona, Barcelona, Spain
- Barcelona Tissue Bank (BTB), Banc de Sang i Teixits (BST), Barcelona, Spain
- Department of Surgery, School of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
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18
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Fasolo A, Galzignato A, Pedrotti E, Chierego C, Cozzini T, Bonacci E, Marchini G. Femtosecond laser-assisted implantation of corneal stroma lenticule for keratoconus. Int Ophthalmol 2021; 41:1949-1957. [PMID: 33625651 PMCID: PMC8087609 DOI: 10.1007/s10792-021-01739-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 02/06/2021] [Indexed: 11/28/2022]
Abstract
Purpose To review recent progress, challenges, and future perspectives of stromal keratophakia for the treatment of advanced keratoconus. Methods We systematically reviewed the literature in the PubMed database, last update June 30, 2020. No language restriction was applied. The authors checked the reference lists of the retrieved articles to identify any additional study of interest.
Results Several techniques have been proposed for the treatment of keratoconus in order to avoid or delay keratoplasty. This was primarily due to the lack of accessibility to donor corneas in many countries. The ease and predictability of the more advanced femtosecond lasers used to correct ametropias by stromal lenticule extraction lead to hypothesize that generated refractive lenticules could be implanted into corneal stromal layers to restore volume and alter the refractive properties of the cornea in patients with corneal ectasias. At the same time, new techniques for preservation, customization, and cellular therapy of the corneal stromal have been developed, directing to the valorization of otherwise discarded byproducts such as donor corneas unsuitable for either lamellar of penetrating keratoplasty. Conclusions Femtosecond laser-assisted stromal keratophakia could be a suitable therapeutic option for the treatment of corneal ectasias, especially in patients with advanced keratoconus, providing biomechanical support recovering the pachimetry to nearly normal value at the same time. The accuracy and predictability of the refractive outcome are yet a critical issue and the patient eligible for the procedure still has to be characterized.
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Affiliation(s)
- Adriano Fasolo
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, U.O.C. di Oculistica-Policlinico G.B. Rossi, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy.,The Veneto Eye Bank Foundation, Venezia, Italy
| | - Alice Galzignato
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, U.O.C. di Oculistica-Policlinico G.B. Rossi, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy
| | - Emilio Pedrotti
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, U.O.C. di Oculistica-Policlinico G.B. Rossi, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy.
| | - Chiara Chierego
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, U.O.C. di Oculistica-Policlinico G.B. Rossi, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy
| | - Tiziano Cozzini
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, U.O.C. di Oculistica-Policlinico G.B. Rossi, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy
| | - Erika Bonacci
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, U.O.C. di Oculistica-Policlinico G.B. Rossi, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy
| | - Giorgio Marchini
- Department of Neurosciences, Biomedicine and Movement Sciences, Eye Clinic, U.O.C. di Oculistica-Policlinico G.B. Rossi, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy
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Regenerative capacity of the corneal transition zone for endothelial cell therapy. Stem Cell Res Ther 2020; 11:523. [PMID: 33276809 PMCID: PMC7716425 DOI: 10.1186/s13287-020-02046-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022] Open
Abstract
The corneal endothelium located on the posterior corneal surface is responsible for regulating stromal hydration. This is contributed by a monolayer of corneal endothelial cells (CECs), which are metabolically active in a continuous fluid-coupled efflux of ions from the corneal stroma into the aqueous humor, preventing stromal over-hydration and preserving the orderly arrangement of stromal collagen fibrils, which is essential for corneal transparency. Mature CECs do not have regenerative capacity and cell loss due to aging and diseases results in irreversible stromal edema and a loss of corneal clarity. The current gold standard of treatment for this worldwide blindness caused by corneal endothelial failure is the corneal transplantation using cadaveric donor corneas. The top indication is Fuchs corneal endothelial dystrophy/degeneration, which represents 39% of all corneal transplants performed. However, the global shortage of transplantable donor corneas has restricted the treatment outcomes, hence instigating a need to research for alternative therapies. One such avenue is the CEC regeneration from endothelial progenitors, which have been identified in the peripheral endothelium and the adjacent transition zone. This review examines the evidence supporting the existence of endothelial progenitors in the posterior limbus and summarizes the existing knowledge on the microanatomy of the transitional zone. We give an overview of the isolation and ex vivo propagation of human endothelial progenitors in the transition zone, and their growth and differentiation capacity to the corneal endothelium. Transplanting these bioengineered constructs into in vivo models of corneal endothelial degeneration will prove the efficacy and viability, and the long-term maintenance of functional endothelium. This will develop a novel regenerative therapy for the management of corneal endothelial diseases.
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20
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Corneal nerves in health and disease. Prog Retin Eye Res 2019; 73:100762. [DOI: 10.1016/j.preteyeres.2019.05.003] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 04/25/2019] [Accepted: 05/01/2019] [Indexed: 12/15/2022]
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The future of keratoplasty: cell-based therapy, regenerative medicine, bioengineering keratoplasty, gene therapy. Curr Opin Ophthalmol 2019; 30:286-291. [PMID: 31045881 DOI: 10.1097/icu.0000000000000573] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW To provide an update on the state of development of novel therapeutic modalities for the treatment of corneal diseases. RECENT FINDINGS Novel corneal therapeutics may be broadly classified as cell therapy, regenerative medicine, bioengineered corneal grafts and gene therapy. Cell therapy encompasses cultivation of cells, such as corneal endothelial cells (CECs) and keratocytes to replenish the depleted native cell population. Regenerative medicine is mainly applicable to the corneal endothelium, and is dependent on the ability of native, healthy CECs to restore the corneal endothelium following trauma or descemetorhexis; this approach may be effective for the treatment of Peter's anomaly and Fuchs endothelial corneal dystrophy (FECD). Bioengineered corneal grafts are synthetic constructs designed to replace cadaveric corneal grafts; tissue-engineered endothelial-keratoplasty grafts and bioengineered stromal grafts have been experimented in animal models with favourable results. Gene therapy with antisense oligonucleotide and CRISPR endonucleases, including deactivated Cas9, may potentially be used to treat FECD and TGFBI-related corneal dystrophies. SUMMARY These novel therapeutic modalities may potentially supersede keratoplasty as the standard of care in the future.
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Optical Coherence Tomography-Guided Transepithelial Phototherapeutic Keratectomy for Central Corneal Opacity in the Pediatric Population. J Ophthalmol 2018; 2018:3923617. [PMID: 30671257 PMCID: PMC6323485 DOI: 10.1155/2018/3923617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/30/2018] [Accepted: 12/05/2018] [Indexed: 11/17/2022] Open
Abstract
Purpose To report the outcomes of optical coherence tomography- (OCT-) guided transepithelial phototherapeutic keratectomy (PTK) for central corneal opacity in the pediatric population. Methods The charts of 10 eyes of 8 children aged 9 to 17 with central corneal opacity from various pathologies who underwent a standardized OCT-guided transepithelial PTK technique at a single private practice institution were retrospectively reviewed. The corneal topographic findings, OCT measurements, and visual results with refractive outcomes were analyzed 6 months after the PTK treatment. Results All 10 eyes tolerated the procedure well without any significant intraoperative or postoperative complications. Uncorrected and best spectacle-corrected visual acuity (BSCVA) significantly improved postoperatively (p < 0.0001 and p=0.0045, respectively). The absolute value of spherical equivalent on cycloplegic refraction significantly improved postoperatively as well (p=0.0014), but there were no significant changes in topographic measurements. Seven out of the 10 eyes had complete resolution of the central corneal opacity on OCT imaging. None of the subjects lost any lines of BSCVA and developed recurrence of the corneal opacity from the primary disease condition or required keratoplasty during the follow-up period. Conclusions OCT-guided transepithelial PTK can provide excellent visual outcomes in pediatric patients with central corneal opacities.
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