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Wróblewska-Czajka E, Dobrowolski D, Wylęgała A, Jurkunas UV, Wylęgała E. Outcomes of Boston Keratoprosthesis Type I Implantation in Poland: A Retrospective Study on 118 Patients. J Clin Med 2024; 13:975. [PMID: 38398288 PMCID: PMC10889181 DOI: 10.3390/jcm13040975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Background: Boston Keratoprosthesis Type I (BI-KPro I) is a synthetic cornea that can be used to restore vision in patients with corneal blindness. This retrospective study evaluated the outcomes of BI-KPro implantation in 118 patients. Material: The mean age of the patients was 56.76 ± 14.24 years. Indications for keratoprosthesis implantation were as follows: graft failure, 47 (39.83%); ocular burn, 38 (32.20%); neurotrophic keratopathy, 11 (9.32%), mucous membrane pemphigoid 9 (7.67%); autoimmune, 6 (5.08%); Stevens-Johnson syndrome, 4 (3.39%); and aniridia (2.54%). Methods: The surgeries were performed between March 2019 and June 2022 at a single clinical center in two locations. The postoperative visual acuity, complications, and need for additional surgical procedures were analyzed. Results: The Best Corrected Visual Acuity before surgery was 0.01 ± 0.006. After one year (V1), it was 0.30 ± 0.27; at two years (V2), it was 0.27 ± 0.26; and at three years (V3), it was 0.21 ± 0.23. The percentage of patients with visual acuity better than 0.1 on the Snellen chart was 37.29% after 1 year, 49.35% after 2 years, and 46.81% after 3 years of follow up. The most common complications were glaucoma (78 patients; 66.1%), corneal melting (22 patients; 18.6%), and retroprosthetic membranes (20 patients; 17.0%). Conclusions: The BI-KPro can significantly improve visual acuity. The worst long-term results were obtained in the group of patients with autoimmune diseases; therefore, careful consideration should be given to implanting BI-KPro in this group. The high incidence of de novo glaucoma or the progression of pre-existing glaucoma suggests the need for careful monitoring.
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Affiliation(s)
- Ewa Wróblewska-Czajka
- Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-760 Katowice, Poland; (D.D.); (E.W.)
- Ophthalmology Department, Railway Hospital in Katowice, 40-760 Katowice, Poland
| | - Dariusz Dobrowolski
- Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-760 Katowice, Poland; (D.D.); (E.W.)
- Ophthalmology Department, Railway Hospital in Katowice, 40-760 Katowice, Poland
- Department of Ophthalmology, Santa Barbara Hospital, 41-200 Sosnowiec, Poland
| | - Adam Wylęgała
- Health Promotion and Obesity Management Unit, Department of Pathophysiology, Faculty of Medical Sciences, Medical University of Silesia, 40-760 Katowice, Poland;
| | - Ula V. Jurkunas
- Cornea Center of Excellence, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Edward Wylęgała
- Clinical Department of Ophthalmology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-760 Katowice, Poland; (D.D.); (E.W.)
- Ophthalmology Department, Railway Hospital in Katowice, 40-760 Katowice, Poland
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Sharma S, Singh S, Shanbhag SS. Case Report: Simultaneous penetrating keratoplasty with autologous simple limbal epithelial transplantation as an alternative to keratoprosthesis. F1000Res 2023; 12:488. [PMID: 37455854 PMCID: PMC10349272 DOI: 10.12688/f1000research.133637.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/18/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction and importance: This case report highlights the multidisciplinary approach required to achieve successful anatomical and functional outcomes, in an eye with total limbal stem cell deficiency (LSCD) associated with underlying corneal scarring and thinning. Presentation of case: A 59-year-old gentleman had poor visual recovery in the right eye (RE) following accidental carbide blast, 1-year before presenting to us. The visual acuity was counting fingers and clinical examination revealed cicatricial entropion involving the upper eyelid, total LSCD, corneal scarring with a central descemetocele and cataract in the RE. Prior to ocular surface reconstruction, entropion correction was performed. Three months later, penetrating keratoplasty combined with cataract surgery and intraocular lens implantation (penetrating keratoplasty (PK) triple), with autologous simple limbal epithelial transplantation (SLET) was performed. The visual acuity was 20/100, 18 months after the surgery, with a clear well-epithelized corneal graft and stable ocular surface. Discussion: LSCD is caused by a decrease in the population and /or function of the limbal epithelial stem cells. Limbal stem cell transplantation (LSCT) is warranted in eyes with total LSCD. In eyes with coexisting corneal scarring, LSCT alone may be inadequate to restore the vision. These eyes require simultaneous or sequential lamellar or full-thickness corneal transplantation for visual rehabilitation. Though, the existing literature favors a sequential approach, where LSCT is performed first followed by corneal transplantation, under certain circumstances such as a thin underlying cornea like in our case, corneal transplantation may have to be combined with LSCT to achieve optimal outcomes. Conclusion: Combining autologous SLET with PK can be performed for visual rehabilitation in eyes with unilateral total LSCD and underlying corneal thinning. Corneal and limbal graft survival is prolonged if existing adnexal comorbidities are addressed before any surgical intervention is planned and adequate time interval is allowed for the surface inflammation to subside.
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Affiliation(s)
- Supriya Sharma
- Cornea and Anterior Segment Services, Shantilal Shanghvi Eye Institute, Mumbai, Maharashtra, India
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Swati Singh
- Ophthalmic Plastic Surgery Services, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Swapna S. Shanbhag
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
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Sharma S, Singh S, Shanbhag SS. Case Report: Simultaneous penetrating keratoplasty with autologous simple limbal epithelial transplantation as an alternative to keratoprosthesis. F1000Res 2023; 12:488. [PMID: 37455854 PMCID: PMC10349272 DOI: 10.12688/f1000research.133637.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction and importance: This case report highlights the multidisciplinary approach required to achieve successful anatomical and functional outcomes, in an eye with total limbal stem cell deficiency (LSCD) associated with underlying corneal scarring and thinning. Presentation of case: A 59-year-old gentleman had poor visual recovery in the right eye (RE) following accidental carbide blast, 1-year before presenting to us. The visual acuity was counting fingers and clinical examination revealed cicatricial entropion involving the upper eyelid, total LSCD, corneal scarring with a central descemetocele and cataract in the RE. Prior to ocular surface reconstruction, entropion correction was performed. Three months later, penetrating keratoplasty combined with cataract surgery and intraocular lens implantation (penetrating keratoplasty (PK) triple), with autologous simple limbal epithelial transplantation (SLET) was performed. The visual acuity was 20/100, 18 months after the surgery, with a clear well-epithelized corneal graft and stable ocular surface. Discussion: LSCD is caused by a decrease in the population and /or function of the limbal epithelial stem cells. Limbal stem cell transplantation (LSCT) is warranted in eyes with total LSCD. In eyes with coexisting corneal scarring, LSCT alone may be inadequate to restore the vision. These eyes require simultaneous or sequential lamellar or full-thickness corneal transplantation for visual rehabilitation. Though, the existing literature favors a sequential approach, where LSCT is performed first followed by corneal transplantation, under certain circumstances such as a thin underlying cornea like in our case, corneal transplantation may have to be combined with LSCT to achieve optimal outcomes. Conclusion: Combining autologous SLET with PK can be performed for visual rehabilitation in eyes with unilateral total LSCD and underlying corneal thinning. Corneal and limbal graft survival is prolonged if existing adnexal comorbidities are addressed before any surgical intervention is planned and adequate time interval is allowed for the surface inflammation to subside.
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Affiliation(s)
- Supriya Sharma
- Cornea and Anterior Segment Services, Shantilal Shanghvi Eye Institute, Mumbai, Maharashtra, India
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Swati Singh
- Ophthalmic Plastic Surgery Services, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Swapna S. Shanbhag
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
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Soleimani M, Ebrahimi Z, Ebrahimi KS, Farhadian N, Shahlaei M, Cheraqpour K, Ghasemi H, Moradi S, Chang AY, Sharifi S, Baharnoori SM, Djalilian AR. Application of biomaterials and nanotechnology in corneal tissue engineering. J Int Med Res 2023; 51:3000605231190473. [PMID: 37523589 PMCID: PMC10392709 DOI: 10.1177/03000605231190473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023] Open
Abstract
Corneal diseases are among the most common causes of blindness worldwide. Regardless of the etiology, corneal opacity- or globe integrity-threatening conditions may necessitate corneal replacement procedures. Several procedure types are currently available to address these issues, based on the complexity and extent of injury. Corneal allograft or keratoplasty is considered to be first-line treatment in many cases. However, a significant proportion of the world's population are reported to have no access to this option due to limitations in donor preparation. Thus, providing an appropriate, safe, and efficient synthetic implant (e.g., artificial cornea) may revolutionize this field. Nanotechnology, with its potential applications, has garnered a lot of recent attention in this area, however, there is seemingly a long way to go. This narrative review provides a brief overview of the therapeutic interventions for corneal pathologies, followed by a summary of current biomaterials used in corneal regeneration and a discussion of the nanotechnologies that can aid in the production of superior implants.
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Affiliation(s)
- Mohammad Soleimani
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Zohreh Ebrahimi
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Kosar Sadat Ebrahimi
- Nano Drug Delivery Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Negin Farhadian
- Substance Abuse Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohsen Shahlaei
- Nano Drug Delivery Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Kasra Cheraqpour
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamed Ghasemi
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Sajad Moradi
- Nano Drug Delivery Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Arthur Y Chang
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Sina Sharifi
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Seyed Mahbod Baharnoori
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Ali R Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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Milad D, Yang Y, Eisa K, Harissi-Dagher M. Review of clinical trials addressing the Boston Keratoprosthesis. Can J Ophthalmol 2023:S0008-4182(23)00166-7. [PMID: 37253429 DOI: 10.1016/j.jcjo.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/24/2022] [Accepted: 05/10/2023] [Indexed: 06/01/2023]
Abstract
OBJECTIVE The Boston Keratoprosthesis (KPro) has gained recognition as an alternative for patients with severe corneal disease and a poor probability of success with traditional penetrating keratoplasty. This review summarizes the knowledge clinical trials have brought to KPro and discusses ongoing trials. DESIGN Systematic review. METHODS A literature review across PubMed, Ovid MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov was performed to identify relevant published clinical trials reporting on the KPro from all years up until September 2021. All published trials were included. RESULTS There are 6 published and 6 ongoing clinical trials studying the Boston KPro. The number of patients included per trial ranged from 8 to 37. The average age of patients included per trial ranged from 39 to 62 years. Patients were followed for an average of 36.3 ± 41.8 months. Fifty percent (3 of 6) of KPro clinical trials were randomized. Indication for KPro was reported in 67% of trials (4 of 6), with primary KPro accounting for 22% of unique eyes (13 of 58) and KPro after corneal graft failure accounting for 41% of unique eyes (24 of 58), when reported. Using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB 2) to assess quality and risk of bias, 50% of trials (3 of 6) had a low risk of bias, 33% (2 of 6) had some bias concerns, and 17% (1 of 6) had a high risk of bias. CONCLUSIONS There are few clinical trials published and underway on the Boston KPro, and none directly compare KPro outcomes with repeat corneal transplantation. There is a need for long-term clinical trials on the KPro to provide quality evidence for clinical decision making.
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Affiliation(s)
- Daniel Milad
- Department of Ophthalmology, University of Montreal Health Centre (CHUM), Montreal, Que
| | - Yelin Yang
- Department of Ophthalmology, University of Montreal Health Centre (CHUM), Montreal, Que
| | - Kerolos Eisa
- Department of Public Health, Queens University, Kingston, Ont
| | - Mona Harissi-Dagher
- Department of Ophthalmology, University of Montreal Health Centre (CHUM), Montreal, Que..
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Mahuvakar S, Jain N, Basu S. Successful use of conjunctival flaps to prolong survival of type I keratoprosthesis in severe bilateral chemical burns: two case reports. F1000Res 2023; 12:521. [PMID: 37920455 PMCID: PMC10618640 DOI: 10.12688/f1000research.131492.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/14/2023] [Indexed: 11/04/2023] Open
Abstract
INTRODUCTION This report describes the use of conjunctival flaps to enable the survival of type I keratoprosthesis (KPro) in two cases of bilateral severe total limbal stem cell deficiency (LSCD) following chemical burns. PRESENTATION OF CASE Two patients had a history of bilateral chemical injury with lime. On examination, the presenting vision was light perception to hand motions and both cases had conjunctivalized ocular surfaces with symblepharon. A modified technique of type I keratoprosthesis was used, where the conjunctivalized corneal pannus was dissected and lifted off as an inferior fornix-based conjunctival flap. This was followed by a standard surgical technique of type I KPro. The flap was then secured over the device and optical opening was made two weeks later. Both the patients had stable ocular surfaces with visual acuity of 20/20 at 2-7 years of follow-up. DISCUSSION In patients with total LSCD with adnexal involvement, type I KPro has unsatisfactory long-term survival because of the risk of repeated epithelial breakdowns and stromal ulceration. With the innovative approach described in this report, type I KPro can be successfully used for sustainable visual improvement in the presence of severe ocular surface disease and symblepharon. CONCLUSION Conjunctival flaps can be used along with type I KPros to improve long-term survival and give sustainable visual outcomes in cases of bilateral corneal blindness due to advanced ocular surface damage.
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Affiliation(s)
- Sheetal Mahuvakar
- Cornea and Refractive Services, Dr. Nagpal's Retina Foundation, Ahmedabad, Gujarat, India
| | - Neha Jain
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, 500034, India
| | - Sayan Basu
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, 500034, India
- Prof. Brien Holden Eye Research Centre (BHERC), LV Prasad Eye Institute, Hyderabad, Telangana, 500034, India
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Huang Y, Lin L, Yang Y, Duan F, Yuan M, Lou B, Lin X. Effect of Tauroursodeoxycholic Acid on Inflammation after Ocular Alkali Burn. Int J Mol Sci 2022; 23:11717. [PMID: 36233018 PMCID: PMC9570278 DOI: 10.3390/ijms231911717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/25/2022] Open
Abstract
Inflammation is the main cause of corneal and retinal damage in an ocular alkali burn (OAB). The aim of this study was to investigate the effect of tauroursodeoxycholic acid (TUDCA) on ocular inflammation in a mouse model of an OAB. An OAB was induced in C57BL/6j mouse corneas by using 1 M NaOH. TUDCA (400 mg/kg) or PBS was injected intraperitoneally (IP) once a day for 3 days prior to establishing the OAB model. A single injection of Infliximab (6.25 mg/kg) was administered IP immediately after the OAB. The TUDCA suppressed the infiltration of the CD45-positive cells and decreased the mRNA and protein levels of the upregulated TNF-α and IL-1β in the cornea and retina of the OAB. Furthermore, the TUDCA treatment inhibited the retinal glial activation after an OAB. The TUDCA treatment not only ameliorated CNV and promoted corneal re-epithelization but also attenuated the RGC apoptosis and preserved the retinal structure after the OAB. Finally, the TUDCA reduced the expression of the endoplasmic reticulum (ER) stress molecules, IRE1, GRP78 and CHOP, in the retinal tissues of the OAB mice. The present study demonstrated that the TUDCA inhibits ocular inflammation and protects the cornea and retina from injury in an OAB mouse model. These results provide a potential therapeutic intervention for the treatment of an OAB.
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Yuan M, Qian X, Huang Y, Ma X, Duan F, Yang Y, Lou B, Lin X. Th17 Activation and Th17/Treg Imbalance in Prolonged Anterior Intraocular Inflammation after Ocular Alkali Burn. Int J Mol Sci 2022; 23:7075. [PMID: 35806082 PMCID: PMC9266712 DOI: 10.3390/ijms23137075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/19/2022] [Accepted: 06/23/2022] [Indexed: 12/12/2022] Open
Abstract
Ocular alkali burn (OAB) is a sight-threatening disease with refractory ocular inflammation causing various blinding complications. Th17 lymphocytes account for the pathogeneses of the autoimmune disease and chronic inflammation, but their role in prolonged anterior intraocular inflammation after OAB is still unknown. A rat OAB model was established for this purpose. Anterior intraocular inflammation was observed in both the acute and late phases of OAB, and histological examination confirmed the presence of inflammatory cell infiltration and fibrin exudation in the anterior segment. Luminex xMAP technology and qPCR were used to evaluate the intraocular levels of cytokines. The levels of IL-1β, IL-6, and TNF-α were significantly elevated during the acute phase. The expression of IL-17A gradually increased from day 7 onwards and remained at a relatively high level. Immunofluorescence was performed to identify Th17 cells. CD4 and IL-17A double positive cells were detected in the anterior chamber from days 7 to 28. Flow cytometry showed that the frequency of Th17 cells increased in both lymph nodes and spleen, while the frequency of Treg cells remained unchanged, resulting in an elevated Th17/Treg ratio. The present study suggests that Th17 activation and Th17/Treg imbalance account for prolonged anterior intraocular inflammation after OAB.
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Li Q, Zhao H, Wang H, Zhao G. Properties of the acellular porcine cornea crosslinked with UVA/riboflavin as scaffolds for Boston Keratoprosthesis. Biomater Adv 2022; 137:212822. [PMID: 35929237 DOI: 10.1016/j.bioadv.2022.212822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/29/2022] [Accepted: 04/20/2022] [Indexed: 06/15/2023]
Abstract
The Boston Keratoprosthesis type I (B-KPro) is widely used in the world, but the lack of donor corneas limits its application. This study aims to prepare the acellular porcine cornea (APC) crosslinked with ultraviolet A (UVA)/riboflavin instead of donor corneas as the scaffold for B-KPro. Decellularization of freeze-thaw combined with biological enzymes resulted in approximately 5 ng/mg DNA residue, the a-Gal removal rate of 99%, and glycosaminoglycans retention at a high level of 46.66 ± 2.59 mg/mg. UVA/ riboflavin cross-linking was adopted to induce the formation of new chemical bonds between adjacent collagen chains in the corneal stroma to improve the mechanical properties and resistance to enzymatic hydrolysis. Through comprehensive analysis of the biomechanics, enzyme degradation, immunogenicity and histological structure of the APC crosslinked at different times, CL3 (irradiation conditions, 365 nm, 3 mW/cm, 80 min, both sides) was selected and transplanted into the rabbit cornea model through interlamellar keratoplasty and penetrating keratoplasty as the scaffold of the B-KPro. Compared with the native porcine cornea (NPC) and APC, the experiment of interlamellar pocket indicated that the structure of CL3 was homogeneous without degradation and vascularization in vivo at 12 weeks after surgery. Simultaneously, the results of transplantation of B-KPro showed complete epithelialization of CL3 within 1 week, and neovascularization of the cornea indicated rejection but could be controlled with immunosuppressants. At 3 months postoperatively, the lens of B-KPro remained transparent, and the structure of CL3 was compact and uniform, accompanied by the migration and proliferation of a large number of stromal cells without degradation, suggesting the CL3 could be a promising corneal substitute.
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Affiliation(s)
- Qing Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan, Shandong, China
| | - Haibin Zhao
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan, Shandong, China; Shenzhen Research Institute of Shandong University, Shenzhen, Guangdong, China.
| | - Hongmei Wang
- Qingdao Chunghao Tissue Engineering Co., Ltd., Qingdao, Shandong, China
| | - Guoqun Zhao
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan, Shandong, China
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Abstract
Limbal stem cell deficiency (LSCD) can cause significant corneal vascularization and scarring and often results in serious visual morbidity. An early and accurate diagnosis can help prevent the same with a timely and appropriate intervention. This review aims to provide an understanding of the different diagnostic tools and presents an algorithmic approach to the management based on a comprehensive clinical examination. Although the diagnosis of LSCD usually relies on the clinical findings, they can be subjective and non-specific. In such cases, using an investigative modality offers an objective method of confirming the diagnosis. Several diagnostic tools have been described in literature, each having its own advantages and limitations. Impression cytology and in vivo confocal microscopy (IVCM) aid in the diagnosis of LSCD by detecting the presence of goblet cells. With immunohistochemistry, impression cytology can help in confirming the corneal or conjunctival source of epithelium. Both IVCM and anterior segment optical coherence tomography can help supplement the diagnosis of LSCD by characterizing the corneal and limbal epithelial changes. Once the diagnosis is established, one of various surgical techniques can be adopted for the treatment of LSCD. These surgeries aim to provide a new source of corneal epithelial stem cells and help in restoring the stability of the ocular surface. The choice of procedure depends on several factors including the involvement of the ocular adnexa, presence of systemic co-morbidities, status of the fellow eye and the comfort level of the surgeon. In LSCD with wet ocular surfaces, autologous and allogeneic limbal stem cell transplantation is preferred in unilateral and bilateral cases, respectively. Another approach in bilateral LSCD with wet ocular surfaces is the use of an autologous stem cell source of a different epithelial lineage, like oral or nasal mucosa. In eyes with bilateral LSCD with significant adnexal issues, a keratoprosthesis is the only viable option. This review provides an overview on the diagnosis and treatment of LSCD, which will help the clinician choose the best option amongst all the therapeutic modalities currently available and gives a clinical perspective on customizing the treatment for each individual case.
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Affiliation(s)
- Anahita Kate
- The Cornea Institute, KVC Campus, LV Prasad Eye Institute, Vijayawada, India
| | - Sayan Basu
- The Cornea Institute, KAR Campus, LV Prasad Eye Institute, Hyderabad, India
- Prof. Brien Holden Eye Research Centre (BHERC), LV Prasad Eye Institute, Hyderabad, Telangana, India
- *Correspondence: Sayan Basu
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Bonneau S, Tong CM, Yang Y, Harissi-Dagher M. The treatment of end-stage corneal disease: penetrating keratoplasty compared with Boston type 1 keratoprosthesis. Graefes Arch Clin Exp Ophthalmol 2022. [PMID: 35384455 DOI: 10.1007/s00417-022-05646-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/19/2022] [Accepted: 03/24/2022] [Indexed: 11/04/2022] Open
Abstract
Penetrating keratoplasty (PKP) yields excellent results for restoring vision in end-stage corneal diseases. However, its success is limited to high-risk diseases such as aniridia, chemical burns, autoimmune corneal diseases, and herpetic eye disease. Boston type 1 keratoprosthesis (BKPro) offers another option to these patients. Since 1992, improvements in perioperative management and device construction have significantly increased the use of BKPro worldwide and challenged the therapeutic role of PKP in these patients. This review aims to evaluate BKPro's place in the treatment algorithm of these high-risk patients to assist surgeons' decision-making. PKP and BKPro are compared in three outcome categories: visual acuity, graft retention and failure, and complications profile. Special attention is given to comparing secondary BKPro versus repeated PKP as well as primary BKPro versus primary PKP. We conclude that secondary BKPro bears a better prognosis than repeated PKP in most high-risk patients. Similarly, primary BKPro likely confers improved outcomes over primary PKP in most high-risk recipients. However, current evidence is based on retrospective designs, and controlled prospective randomized trials are required to validate these conclusions.
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Sharifi S, Sharifi H, Akbari A, Lei F, Dohlman CH, Gonzalez-Andrades M, Guild C, Paschalis EI, Chodosh J. Critical media attributes in E-beam sterilization of corneal tissue. Acta Biomater 2022; 138:218-227. [PMID: 34755604 PMCID: PMC8738149 DOI: 10.1016/j.actbio.2021.10.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 01/17/2023]
Abstract
When ionizing irradiation interacts with a media, it can form reactive species that can react with the constituents of the system, leading to eradication of bioburden and sterilization of the tissue. Understanding the media's properties such as polarity is important to control and direct those reactive species to perform desired reactions. Using ethanol as a polarity modifier of water, we herein generated a series of media with varying relative polarities for electron beam (E-beam) irradiation of cornea at 25 kGy and studied how the irradiation media's polarity impacts properties of the cornea. After irradiation of corneal tissues, mechanical (tensile strength and modulus, elongation at break, and compression modulus), chemical, optical, structural, degradation, and biological properties of the corneal tissues were evaluated. Our study showed that irradiation in lower relative polarity media improved structural properties of the tissues yet reduced optical transmission; higher relative polarity reduced structural and optical properties of the cornea; and intermediate relative polarity (ethanol concentrations = 20-30% (v/v)) improved the structural properties, without compromising optical characteristics. Regardless of media polarity, irradiation did not negatively impact the biocompatibility of the corneal tissue. Our data shows that the absorbed ethanol can be flushed from the irradiated cornea to levels that are nontoxic to corneal and retinal cells. These findings suggest that the relative polarity of the irradiation media can be tuned to generate sterilized tissues, including corneal grafts, with engineered properties that are required for specific biomedical applications. STATEMENT OF SIGNIFICANCE: Extending the shelf-life of corneal tissue can improve general accessibility of cornea grafts for transplantation. Irradiation of donor corneas with E-beam is an emerging technology to sterilize the corneal tissues and enable their long-term storage at room temperature. Despite recent applications in clinical medicine, little is known about the effect of irradiation and preservation media's characteristics, such as polarity on the properties of irradiated corneas. Here, we have showed that the polarity of the media can be a valuable tool to change and control the properties of the irradiated tissue for transplantation.
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Affiliation(s)
- Sina Sharifi
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA,Corresponding authors: James Chodosh, MD MPH, Massachusetts Eye and Ear, Boston, MA, 02114, USA. , Sina Sharifi, PhD, Massachusetts Eye and Ear, Boston, MA, 02114, USA.
| | - Hannah Sharifi
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Ali Akbari
- Solid Tumor Research Center, Research Institute for Cellular and Molecular Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Fengyang Lei
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Claes H. Dohlman
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Miguel Gonzalez-Andrades
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA,Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Department of Ophthalmology, Reina Sofia University Hospital and University of Cordoba, Cordoba, Spain
| | | | - Eleftherios I. Paschalis
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - James Chodosh
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA,Corresponding authors: James Chodosh, MD MPH, Massachusetts Eye and Ear, Boston, MA, 02114, USA. , Sina Sharifi, PhD, Massachusetts Eye and Ear, Boston, MA, 02114, USA.
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13
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Wu J, Wu T, Li J, Wang L, Huang Y. DSAEK or DMEK for failed penetrating keratoplasty: a systematic review and single-arm meta-analysis. Int Ophthalmol 2021; 41:2315-2328. [PMID: 34117964 DOI: 10.1007/s10792-021-01778-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 03/06/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To review the published literature on indications and outcomes of DSAEK/DSEK and DMEK for the treatment of failed penetrating keratoplasty. DESIGN This is a systematic review and single-arm meta-analysis. METHODS Literature searches were conducted in PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews. Prospective and retrospective studies reporting DSAEK/DSEK or DMEK after failed penetrating keratoplasty were included. Primary outcome measures are graft survival and detachment rates, as well as postoperative visual outcomes. RESULTS A total of 25 studies with 970 patients/989 eyes were included, comprising 735 patients with 746 eyes which underwent DSAEK/DSEK surgery and 235 patients with 243 eyes which underwent DMEK surgery, all of them following a previously failed PK. There were no randomized controlled studies. In all of the DSAEK-PK studies, the graft failure rate was 18% (10%, 26%), the detachment rate was 15% (9%, 22%) and the rejection rate was 7% (3%, 12%) by the time of the last follow-up. And in all of the DMEK-PK studies, the graft failure rate was 14% (4%, 27%), the detachment rate was 42% (28%, 56%) and the rejection rate was 7% (2%, 16%). The mean visual acuity of the DSAEK-PK and DMEK-PK groups is 0.65 ± 0.18 and 0.43 ± 0.23 logMAR, respectively, at 6 months postoperatively. CONCLUSIONS Endothelial keratoplasty for treatment of failed penetrating keratoplasty led to improved vision and graft clarity in most recipients. Though graft survival rates and rejection rates were comparable between the two groups, the DMEK-PK group showed better visual outcomes with higher detachment rate.
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Affiliation(s)
- Jie Wu
- Department of Ophthalmology, the Third Medical Centre, Chinese PLA General Hospital, Fuxing Road 28, Beijing, 100853, China
| | - Tengyun Wu
- Department of Ophthalmology, the Third Medical Centre, Chinese PLA General Hospital, Fuxing Road 28, Beijing, 100853, China
| | - Jianhang Li
- Hospital of the 61150 Troop of Chinese PLA, Yulin, Shannxi, China
| | - Liqiang Wang
- Department of Ophthalmology, the Third Medical Centre, Chinese PLA General Hospital, Fuxing Road 28, Beijing, 100853, China.
| | - Yifei Huang
- Department of Ophthalmology, the Third Medical Centre, Chinese PLA General Hospital, Fuxing Road 28, Beijing, 100853, China.
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14
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Vazirani J, Donthineni PR, Goel S, Sane SS, Mahuvakar S, Narang P, Shanbhag SS, Basu S. Chronic cicatrizing conjunctivitis: A review of the differential diagnosis and an algorithmic approach to management. Indian J Ophthalmol 2021; 68:2349-2355. [PMID: 33120615 PMCID: PMC7774214 DOI: 10.4103/ijo.ijo_604_20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Cicatrizing conjunctivitis constitutes a group of chronic local and systemic disorders that cause conjunctival scarring. A systematic approach is required to sift through the clinical history, examination, and laboratory investigations of patients to arrive at the correct diagnosis of the underlying cause. Establishing the etiology is critical, as the therapeutic approach changes based on the cause of conjunctival inflammation. Effective management of patients with the condition requires knowledge of multiple modalities such as systemic immunosuppressive therapy, use of scleral contact lenses, and surgery for ocular surface and vision improvement. We review the clinical features of this condition and present diagnostic and treatment algorithms to help simplify the complexities in its management. This review attempts to place all the relevant information on chronic cicatrizing conjunctivitis together in one place for the benefit of cornea and ocular surface specialists, general ophthalmologists, and ophthalmology residents.
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Affiliation(s)
- Jayesh Vazirani
- Center for Excellence in Cornea and Ocular Surface Disorders, Excel Eye Care, Ahmedabad, Gujarat, India
| | | | - Sahil Goel
- Department of Ophthalmology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Sayali S Sane
- The Cornea Institute, L V Prasad Eye Institute, GMR Varalakshmi Campus, Visakhapatnam, Andhra Pradesh, India
| | - Sheetal Mahuvakar
- Cornea and Refractive Services, Dr Nagpal's Retina Foundation, Ahmedabad, Gujarat, India
| | - Purvasha Narang
- Cornea, Refractive Surgery and Ocular Surface Services, L J Eye Institute, Ambala, Haryana, India
| | - Swapna S Shanbhag
- The Cornea Institute, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Sayan Basu
- The Cornea Institute, L V Prasad Eye Institute, Hyderabad, Telangana, India
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15
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Abstract
Purpose: To review the surgical management options in ocular chemical burn, including newer advances.Methods: Online literature search of published articles over last 5 years on surgical management of ocular chemical burn and newer advances were performed on December 30, 2020.Results: Following literature search and screening using adequate filters, 67 review articles on surgical management of ocular chemical burns were retrieved. The review talks about the surgical management options starting from Debridement in acute stage to various visual rehabilitative procedures in the chronic stage. The review also highlights the evolving surgical advances in this field.Conclusion: It is imperative to choose adequate surgical tool wherever applicable; current review discusses the role of each surgical option at different clinical stages in detail.
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Affiliation(s)
- Priyanshi Awasthi
- Department of Ophthalmology, All India Institute of Medical Sciences, Patna, India
| | - Prabhakar Singh
- Department of Ophthalmology, All India Institute of Medical Sciences, Patna, India
| | - Amit Raj
- Department of Ophthalmology, All India Institute of Medical Sciences, Patna, India
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16
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Sharifi S, Sharifi H, Guild C, Islam MM, Tran KD, Patzer C, Dohlman CH, Paschalis EI, Gonzalez-Andrades M, Chodosh J. Toward electron-beam sterilization of a pre-assembled Boston keratoprosthesis. Ocul Surf 2021; 20:176-184. [PMID: 33667673 DOI: 10.1016/j.jtos.2021.02.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/07/2021] [Accepted: 02/18/2021] [Indexed: 12/26/2022]
Abstract
PURPOSE To evaluate the effects of electron-beam (E-beam) irradiation on the human cornea and the potential for E-beam sterilization of Boston keratoprosthesis (BK) devices when pre-assembled with a donor cornea prior to sterilization. METHODS Human donor corneas and corneas pre-assembled in BK devices were immersed in recombinant human serum albumin (rHSA) media and E-beam irradiated at 25 kGy. Mechanical (tensile strength and modulus, and compression modulus), chemical, optical, structural, and degradation properties of the corneal tissue after irradiation and after 6 months of preservation were evaluated. RESULTS The mechanical evaluation showed that E-beam irradiation enhanced the tensile and compression moduli of human donor corneas, with no impact on their tensile strength. By chemical and mechanical analysis, E-beam irradiation caused a minor degree of crosslinking between collagen fibrils. No ultrastructural changes due to E-beam irradiation were observed. E-beam irradiation slightly increased the stability of the cornea against collagenase-induced degradation and had no impact on glucose diffusion. The optical evaluation showed transparency of the cornea was maintained. E-beam irradiated corneal tissues and BK-cornea pre-assembled devices were stable for 6 months after room-temperature preservation. CONCLUSIONS E-beam irradiation generated no detrimental effects on the corneal tissues or BK-cornea pre-assembled devices and improved native properties of the corneal tissue, enabling prolonged preservation at room temperature. The pre-assembly of BK in a donor cornea, followed by E-beam irradiation, offers the potential for an off-the-shelf, ready to implant keratoprosthesis device.
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Affiliation(s)
- Sina Sharifi
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Hannah Sharifi
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | | | - Mohammad Mirazul Islam
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Khoa D Tran
- Vision Research Laboratory, Lions VisionGift, Portland, OR, USA
| | - Corrina Patzer
- Vision Research Laboratory, Lions VisionGift, Portland, OR, USA
| | - Claes H Dohlman
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Eleftherios I Paschalis
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Miguel Gonzalez-Andrades
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Department of Ophthalmology, Reina Sofia University Hospital and University of Cordoba, Cordoba, Spain.
| | - James Chodosh
- Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
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17
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Abstract
Importance Limbal stem cell transplant (LSCT) can be categorized as direct autologous limbal transplant (AULT), direct allogenic limbal transplant (ALLT), cultivated autologous limbal stem cells transplant (cAULT), and cultivated allogenic limbal stem cells transplant (cALLT). To our knowledge, there is no study directly comparing the outcomes and complications of these procedures. Objective To evaluate the outcomes of different LSCT procedures. Data Source We searched PubMed, EMBASE, Web of Science, and Cochrane without language filter for peer-reviewed articles about LSCT. The latest search was performed on June 30, 2019. Study Selection Clinical studies with the outcome of at least 20 eyes after LSCT were included. Animal studies and studies of other surgical interventions were excluded. Data Extraction and Synthesis Two reviewers independently abstracted the data from each study. Heterogeneity was evaluated with the I2 statistic, and a meta-analysis was performed using the random-effects model. Main Outcomes and Measures Outcome measures included the improvement of ocular surface, visual acuity (VA), and adverse events of recipient eyes and donor eyes. Results Forty studies (2202 eyes) with a mean (SD) follow-up of 31.3 (20.9) months met the inclusion criteria. The mean (SD) age of study participants was 38.4 (13.1) years, and men accounted for 74%. The number of eyes that underwent AULT, ALLT, cAULT, and cALLT were 505, 742, 771, and 184, respectively. Improvement of the ocular surface was achieved in 74.5% of all eyes, 85.7% of eyes after AULT (95% CI, 79.5%-90.3%), 84.7% after cAULT (95% CI, 77.2%-90.0%), 57.8% after ALLT (95% CI, 49.0%-66.1%), and 63.2% after cALLT (95% CI, 49.3%-75.2%). Autologous limbal transplantation resulted in a greater VA improvement rate (76%) than did the other 3 procedures (cAULT: 56.4%; ALLT: 52.3%; cALLT: 43.3%; all P < .001). The most common adverse events in all recipient eyes were recurrent/persistent epithelial erosion (10.5%; 95% CI, 7.2%-23.3%) and elevated intraocular pressure (intraocular pressure, 1.7%; 95% CI, 0.5%-7.8%). Patients who underwent ALLT had the highest rate of recurrent epithelial erosion (27.8%; 95% CI, 17.1%-41.9%) and intraocular pressure elevation (6.3%; 95% CI, 1.8%-19.4%). Conclusions and Relevance These findings suggest LSCT can improve or stabilize the corneal surface with a low rate of severe ocular complications and that autologous LSCT may have a higher success rate and fewer complications than allogenic LSCT.
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Affiliation(s)
- Qihua Le
- David Geffen School of Medicine, Stein Eye Institute, Cornea Division, University of California, Los Angeles.,Eye, Ear, Nose, and Throat Hospital of Fudan University, Shanghai, China
| | - Tulika Chauhan
- David Geffen School of Medicine, Stein Eye Institute, Cornea Division, University of California, Los Angeles.,Mahatma Gandhi Memorial Medical College, DAVV University, Indore, MP, India
| | - Madeline Yung
- David Geffen School of Medicine, Stein Eye Institute, Cornea Division, University of California, Los Angeles
| | - Chi-Hong Tseng
- David Geffen School of Medicine, Division of General Internal Medicine and Health Services Research, University of California, Los Angeles
| | - Sophie X Deng
- David Geffen School of Medicine, Stein Eye Institute, Cornea Division, University of California, Los Angeles
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18
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Abstract
Treatment of limbal stem cell deficiency is challenging. Multiple options can be adopted according to the underlying cause and the patient and physician preferences. Stem cell transplant is a common treatment modality and several techniques have been described with outcomes varying by the laterality of the condition. Keratoprosthesis is a preferred option for bilateral conditions. Indications for type 1 and type 2 keratoprosthesis differ and the past 2 decades have seen a revolution in the field of keratoprosthesis with encouraging and improved outcomes. Management also includes preventive measures and measures to optimize/stabilize the ocular surface that would go a long way in reducing the deterioration of the ocular surface. The aim of this review is to provide an overview of the currently available techniques and to present a comprehensive algorithm to assist in decision making for unilateral and bilateral limbal stem cell deficiency.
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Affiliation(s)
- Geetha Iyer
- CJ Shah Cornea Services, Dr. G. Sitalakshmi Memorial Clinic for Ocular Surface Disorders, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
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19
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Hui PC, Pereira LA, Dore R, Chen S, Taniguchi E, Chodosh J, Dohlman CH, Paschalis EI. Intrinsic Optical Properties of Boston Keratoprosthesis. Transl Vis Sci Technol 2020; 9:10. [PMID: 33200051 PMCID: PMC7645245 DOI: 10.1167/tvst.9.12.10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/07/2020] [Indexed: 12/03/2022] Open
Abstract
Purpose To benchmark the optical performance of Boston Keratoprosthesis (B-KPro). Methods Back focal lengths (BFL) of B-KPros for various eye axial lengths were measured using an optical bench, International Organization for Standardization–certified for intraocular lens characterization, and compared against manufacturer's specification. The modulation transfer function (MTF) and the resolution efficiencies were measured. The theoretical geometry-dependent higher-order aberrations (HOA) were calculated. The devices were characterized with optical profilometry for estimating the surface scattering. Aberration correction and subsequent image quality improvement were simulated in CODE-V. Natural scene-imaging was performed in a mock ocular environment. Retrospective analysis of 15 B-KPro recipient eyes were presented to evaluate the possibility of achieving 20/20 best-corrected visual acuity (BCVA). Results BFL measurements were in excellent agreement with the manufacturer-reported values (r = 0.999). The MTF specification exceeded what is required for achieving 20/20 visual acuity. Astigmatism and field curvature, correctable in simulations, were the primary aberrations limiting imaging performance. Profilometry of the anterior surface revealed nanoscale roughness (root-mean-square amplitude, 30–50 nm), contributing negligibly to optical scattering. Images of natural scenes obtained with a simulated B-KPro eye demonstrated good central vision, with 10/10 visual acuity (equivalent to 20/20). Full restoration of 20/20 BCVA was obtainable for over 9 years in some patients. Conclusions Theoretical and experimental considerations demonstrate that B-KPro has the optical capacity to restore 20/20 BCVA in patients. Further image quality improvement can be anticipated through correction of HOAs. Translational Relevance We establish an objective benchmark to characterize the optics of the B-KPro and other keratoprosthesis and propose design changes to allow improved vision in B-KPro patients.
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Affiliation(s)
- Pui-Chuen Hui
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.,Schepens Eye Research Institute, Boston Keratoprosthesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Leonardo A Pereira
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.,CAPES Foundation, Ministry of Education of Brazil, Brasilia, Brazil
| | - Renald Dore
- University of Rochester, Institute of Optics, Rochester, NY, USA
| | - Shengtong Chen
- University of Rochester, Institute of Optics, Rochester, NY, USA
| | - Elise Taniguchi
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.,Schepens Eye Research Institute, Boston Keratoprosthesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - James Chodosh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Claes H Dohlman
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.,Schepens Eye Research Institute, Boston Keratoprosthesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Eleftherios I Paschalis
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.,Schepens Eye Research Institute, Boston Keratoprosthesis Laboratory, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
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20
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Ghareeb AE, Lako M, Figueiredo FC. Recent Advances in Stem Cell Therapy for Limbal Stem Cell Deficiency: A Narrative Review. Ophthalmol Ther 2020; 9:809-831. [PMID: 32970311 PMCID: PMC7708613 DOI: 10.1007/s40123-020-00305-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/15/2020] [Indexed: 12/13/2022] Open
Abstract
Destruction of the limbus and depletion of limbal stem cells (LSCs), the adult progenitors of the corneal epithelium, leads to limbal stem cell deficiency (LSCD). LSCD is a rare, progressive ocular surface disorder which results in conjunctivalisation and neovascularisation of the corneal surface. Many strategies have been used in the treatment of LSCD, the common goal of which is to regenerate a self-renewing, transparent, and uniform epithelium on the corneal surface. The development of these techniques has frequently resulted from collaboration between stem cell translational scientists and ophthalmologists. Direct transplantation of autologous or allogeneic limbal tissue from a healthy donor eye is regarded by many as the technique of choice. Expansion of harvested LSCs in vitro allows smaller biopsies to be taken from the donor eye and is considered safer and more acceptable to patients. This technique may be utilised in unilateral cases (autologous) or bilateral cases (living related donor). Recently developed, simple limbal epithelial transplant (SLET) can be performed with equally small biopsies but does not require in vitro cell culture facilities. In the case of bilateral LSCD, where autologous limbal tissue is not available, autologous oral mucosa epithelium can be expanded in vitro and transplanted to the diseased eye. Data on long-term outcomes (over 5 years of follow-up) for many of these procedures is needed, and it remains unclear how they produce a self-renewing epithelium without recreating the vital stem cell niche. Bioengineering techniques offer the ability to re-create the physical characteristics of the stem cell niche, while induced pluripotent stem cells offer an unlimited supply of autologous LSCs. In vivo confocal microscopy and anterior segment OCT will complement impression cytology in the diagnosis, staging, and follow-up of LSCD. In this review we analyse recent advances in the pathology, diagnosis, and treatment of LSCD.
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Affiliation(s)
- Ali E Ghareeb
- Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, UK.,Department of Ophthalmology, Royal Victoria Infirmary, Newcastle Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK
| | - Majlinda Lako
- Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, UK
| | - Francisco C Figueiredo
- Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, UK. .,Department of Ophthalmology, Royal Victoria Infirmary, Newcastle Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK.
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21
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Chen Y, Wang C, Liu Q, Wang Z, Gao M. Comparison of the Clinical Efficacy of Boston Keratoprosthesis Type I and Repetitive Penetrating Keratoplasty for Refractory Keratopathy. J Craniofac Surg 2020; 31:e194-9. [PMID: 31977683 DOI: 10.1097/SCS.0000000000006164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To compare the clinical efficacy of Boston Keratoprosthesis type I (B-KProI) and penetrating keratoplasty (PKP) for patients with refractory keratopathy after 1failed PKP in China. METHOD The 42 consecutive cases with refractory keratopathy after 1 failed PKP, from July 2010 to December 2014, were divided into 2 groups according to the surgical method: KPro group (n = 21) and PKP group (n = 21). Visual acuity (LogMAR), corneal graft transparency, postoperative complications and corneal graft survival rate were observed. The follow-up time was 2 years. The Kaplan-Meier curve was used to analyze the survival rate of the two groups of corneal grafts. RESULTS The average best corrected visual acuity (BCVA) at 1, 6, 12, 18, and 24 months in KPro group were significantly lower than PKP group (P < 0.01). The best postoperative visual acuity and BCVA at postoperative 2 years in KPro group were lower than PKP group. The success rate of KPro group (86%) were significantly higher than PKP group (43%) (P < 0.01). There were no significant differences in indicate of complications in 2 groups including secondary glaucoma, secondary infectious corneal ulcer, corneal graft melting and endophthalmitis (P > 0.05). CONCLUSION Compared with repetitive PKP, B-KProI had a higher success rate, improved postoperative visual acuity, reduced postoperative corneal transplant rejection rates and improved corneal graft survival rate.
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22
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Shanbhag SS, Senthil S, Mohamed A, Basu S. Outcomes of the Boston type 1 and the Aurolab keratoprosthesis in eyes with limbal stem cell deficiency. Br J Ophthalmol 2020; 105:473-478. [PMID: 32554443 DOI: 10.1136/bjophthalmol-2020-316369] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/28/2020] [Accepted: 05/23/2020] [Indexed: 11/04/2022]
Abstract
PURPOSE To analyse the outcomes of keratoprosthesis in eyes with limbal stem cell deficiency (LSCD) and to compare the outcomes in two different keratoprosthesis devices. METHODS This was a single-centre retrospective comparative case series which included 81 eyes of patients with severe bilateral corneal blindness secondary to LSCD. The patients underwent either Boston type 1 keratoprosthesis (Boston Kpro, n=44) or Aurolab keratoprosthesis (AuroKpro, n=37) implantation. The primary outcome measures of anatomical retention and functional recovery of 20/200 or better visual acuity at yearly time points until 5 years of follow-up were compared between the two groups. RESULTS The most common indication overall was chemical injury (64.2%). Anatomical retention rates were similar in the Boston Kpro (30/44, 68.2%) and AuroKpro (23/37, 62.2%) groups (p=0.89). Kaplan-Meier survival rates at 5 years of follow-up were greater for the Boston Kpro group with respect to both anatomical retention (58.51%±9% vs 43.8±12%; p=0.23) as well as functional recovery (42.61%±8% vs 35.03±10%; p=0.9); these differences were not statistically significant. Overall, the most common complication was new-onset glaucoma (59%; 48/81). The difference in incidence rate of this complication was not statistically significant among the two groups (p=0.09). CONCLUSION Keratoprosthesis is an effective treatment option for patients with corneal blindness secondary to LSCD. In a setting where LSCD is a common cause of corneal blindness, the AuroKpro, when available can be considered an alternative to the Boston Kpro to achieve anatomical and functional success in patients who otherwise would not have access to this device.
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Affiliation(s)
- Swapna S Shanbhag
- The Cornea Institute, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Sirisha Senthil
- VST Glaucoma Center, L V Prasad Eye Institute, Hyderabad, Andhra Pradesh, India
| | - Ashik Mohamed
- Ophthalmic Biophysics, L V Prasad Eye Institute, Hyderabad, India
| | - Sayan Basu
- The Cornea Institute, L V Prasad Eye Institute, Hyderabad, Telangana, India .,Brien Holden Eye Research Centre (BHERC), L V Prasad Eye Institute, Hyderabad, Telangana, India
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23
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Abstract
The use of Boston type 1 keratoprosthesis (BKPro) has significantly increased worldwide. It is no longer considered a procedure of last resort but a reasonable option for patients with otherwise poor prognosis for a traditional penetrating keratoplasty. BKPro was approved by the Food and Drug Administration in 1992 for bilateral severe corneal blindness due to multiple corneal transplant failure. Over the years, indications have extended beyond recurrent immunologic rejection to include other conditions such as chemical injury and other causes of bilateral limbal stem cell deficiency, extensive corneal neovascularization, neurotrophic corneas and hypotony, among others. Numerous advances in the design of the BKPro, improvement of preoperative, intraoperative and postoperative management have resulted in favorable outcomes and a reduction in postoperative complications. Accordingly, many studies have shown that implantation of this device is highly effective in restoring vision with very good short-term outcomes. However, due to the lifetime risk of sight-threatening complications after BKPro implantation, a longer follow-up period should provide outcomes that are more realistic. In this review, the authors examined only the results of publications with an average of at least 2 years of follow-up. The overall intermediate to long-term visual outcomes and retention rate in BKPro seem to be favorable. However, autoimmune diseases and cicatrizing conditions continue to show a higher incidence of postoperative complications that require further management.
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Affiliation(s)
- Manachai Nonpassopon
- Department of Ophthalmology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Muanploy Niparugs
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA.,Department of Ophthalmology, Faculty of Medicine, Chaing Mai University, Chaing Mai, Thailand
| | - Maria Soledad Cortina
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
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24
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Abstract
Effects of chemical injuries on the cornea and limbus have been widely studied; however, little is known about glaucoma after ocular chemical injuries. We herein investigated the incidence, risk factors, and outcome of glaucoma in patients with ocular chemical burns. Medical records were reviewed of patients who visited our clinic for chemical injuries to the ocular surface. Patients were divided into glaucoma and non-glaucoma groups based on high intraocular pressure (IOP) readings. Clinical characteristics, treatment method, and therapeutic and visual outcomes were compared between the two groups. Of 29 patients (40 eyes), 9 patients (15 eyes, 37.5%) were diagnosed with glaucoma at 2.64 ± 2.92 months after injury. Factors associated with glaucoma included male gender (p = 0.0114), bilateral ocular involvement (p = 0.0478), severe ocular surface involvement (Dua grades IV-VI, p = 0.0180), poor initial visual acuity (p = 0.0136), high initial IOP (p < 0.0001), pupil involvement at initial examination (p = 0.0051), and the need for amniotic membrane transplantation in the acute stage (p = 0.0079). At final follow-up, IOP was uncontrolled in 3 eyes (20.0%), and visual acuity was worse in the glaucoma group than in the non-glaucoma group (logMAR 2.94 ± 1.86 vs 0.34 ± 0.69, p < 0.0001). These findings suggest that careful evaluation and intensive treatment for glaucoma are essential in patients with severe ocular burns.
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Affiliation(s)
- Se Hyun Choi
- Department of Ophthalmology, Hallym University Sacred Heart Hospital, Anyang-si, Gyeonggi-do, Republic of Korea.,Laboratory of Ocular Regenerative Medicine and Immunology, Seoul National University Hospital Biomedical Research Institute, Seoul, Korea
| | - Mee Kum Kim
- Laboratory of Ocular Regenerative Medicine and Immunology, Seoul National University Hospital Biomedical Research Institute, Seoul, Korea.,Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
| | - Joo Youn Oh
- Laboratory of Ocular Regenerative Medicine and Immunology, Seoul National University Hospital Biomedical Research Institute, Seoul, Korea. .,Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
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Christensen JM, Shanbhag SS, Shih GC, Goverman J, Pomahac B, Chodosh J, Ehrlichman RJ. Multidisciplinary Treatment to Restore Vision in Ocular Burns. J Burn Care Res 2019; 41:859-865. [PMID: 31808803 DOI: 10.1093/jbcr/irz201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Periorbital burns generate contraction and distortion of periorbital soft tissue, causing eyelid malfunction, further contributing to loss of vision from corneal scarring or perforation. We present our multidisciplinary algorithm to restore vision in patients with burn-related bilateral corneal blindness with light perception. Chart review was performed for four consecutive burn patients requiring periocular reconstruction and keratoprosthesis. Initial treatment included globe coverage with eyelid releases and grafts. Strategy of corneal replacement was determined by eyelid position and function and sufficiency of tear production. All patients were corneal blind with light perception only and cicatricial ectropion. The eye with better visual prognosis was reconstructed. Eyelid reconstruction procedures consisted of lid releases with full-thickness skin graft (FTSG) or split-thickness skin graft (STSG). Two patients regained adequate lid function and underwent standard keratoprosthesis placement. Two underwent mucous membrane grafts followed by keratoprosthesis. All patients experienced improved postoperative vision in their reconstructed eye. Corneal injury due to periocular burns can lead to blindness. Early involvement of ophthalmology, protective measures, and early ectropion release are critical. For severe burns, a multidisciplinary approach, where adequate globe protection is followed by keratoprosthesis placement, can effectively restore vision in patients with burn-related corneal blindness.
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Affiliation(s)
- Joani M Christensen
- Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston
| | | | - Grace C Shih
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston
| | - Jeremy Goverman
- Department of Surgery, Massachusetts General Hospital, Boston
| | - Bohdan Pomahac
- Division of Plastic and Reconstructive Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - James Chodosh
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston
| | - Richard J Ehrlichman
- Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston
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26
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Silva RO, Costa BLD, Silva FRD, Silva CND, Paiva MBD, Dourado LFN, Malachias Â, Souza Araújo AAD, Nunes PS, Silva-cunha A. Treatment for chemical burning using liquid crystalline nanoparticles as an ophthalmic delivery system for pirfenidone. Int J Pharm 2019; 568:118466. [DOI: 10.1016/j.ijpharm.2019.118466] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 06/23/2019] [Accepted: 06/24/2019] [Indexed: 12/15/2022]
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Basu S, Serna-Ojeda JC, Senthil S, Pappuru RR, Bagga B, Sangwan V. The Aurolab Keratoprosthesis (KPro) versus the Boston Type I Kpro: 5-year Clinical Outcomes in 134 Cases of Bilateral Corneal Blindness. Am J Ophthalmol 2019; 205:175-183. [PMID: 30905723 DOI: 10.1016/j.ajo.2019.03.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 03/08/2019] [Accepted: 03/10/2019] [Indexed: 11/17/2022]
Abstract
PURPOSE To compare the clinical outcomes of Boston Type I keratoprosthesis (Boston Kpro) with its low-cost version, the Aurolab Kpro (auroKPro). DESIGN Retrospective comparative case series. METHODS This study included 134 eyes of 130 patients with severe bilateral corneal blindness but with wet ocular surfaces. The patients underwent either Boston Kpro (n = 78) or auroKPro (n = 56) implantation based on the device availability and patient's affordability. The primary outcome measurements were anatomical retention (defined as absence of device extrusion, exchange, or explantation) and functional recovery of 20/200 or better visual acuity at yearly time points until 5-years of follow-up. RESULTS Limbal stem cell deficiency was the most common indication (60.5%) for surgery, followed by multiple failed grafts (35%). Both groups were comparable at baseline with respect to indications for surgery and associated ocular co-morbidities (P > 0.05). The overall anatomical retention rates were similar in the Boston Kpro (55 of 78, 70.5%) and auroKPro (35 of 56, 62.5%) groups (P = 0.11). Kaplan-Meier survival rates at 5 years of follow-up were greater for the Boston Kpro with respect to both anatomical retention (63 ± 6% vs. 43.4 ± 10%, respectively; P = 0.057) and functional recovery (42.4 ± 6% vs. 32.2 ± 7%, respectively; P = 0.345), but these differences were not statistically significant. Complications such as intraoperative device breakage (7%) and postoperative extrusions (12.5%) were significantly more common with the auroKPro (P = 0.023). CONCLUSIONS Both the auroKPro and the Boston Kpro are effective treatment options for patients with severe bilateral corneal blindness. The auroKPro can be considered an alternative to the Boston Kpro when affordability or availability of the Boston Kpro is a limiting factor.
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Affiliation(s)
- Sayan Basu
- Tej Kohli Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India.
| | | | - Sirisha Senthil
- VST Glaucoma Centre, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Rajeev Reddy Pappuru
- Kannuri Santhamma Centre for Vitreo-Retinal Diseases, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Bhupesh Bagga
- Tej Kohli Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Virender Sangwan
- Tej Kohli Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
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28
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Abstract
Ocular chemical injuries vary in severity, with the more severe end of the spectrum having profound visual consequences and medicolegal implications. Grading of ocular injuries is critical for determining acute treatment and visual prognosis. Poor immediate management results in more challenging treatment of acute disease. Similarly, poorly controlled acute disease results in more treatment-resistant chronic ocular disease. Despite several decades of research and public health initiatives, simple and effective interventions such as wearing protective eyewear and immediate irrigation of eyes remain as key challenges. Education and prevention are therefore important public health messages. Hurdles in the acute management of disease include poor evidence-base for commonly used treatments (e.g. based on experimental animal studies), reduced treatment adherence rates and high clinic non-attendance rates. The evolution of treatment strategies, particularly limbal stem cell transplantation, has revolutionised the visual and cosmetic outcomes in chronic phases of disease. It is therefore increasingly important to consider tertiary referral for patients with limbal stem cell failure or vision-limiting corneal scarring.
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Affiliation(s)
- Mukhtar Bizrah
- Imperial College Healthcare NHS Trust, Western Eye Hospital, 153-173 Marylebone Road, London, NW1 5QH, UK.
| | - Ammar Yusuf
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Sajjad Ahmad
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London, EC1V 2PD, UK
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30
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de la Paz MF, Salvador-Culla B, Charoenrook V, Temprano J, Álvarez de Toledo J, Grabner G, Michael R, Barraquer RI. Osteo-odonto-, Tibial bone and Boston keratoprosthesis in clinically comparable cases of chemical injury and autoimmune disease. Ocul Surf 2019; 17:476-483. [DOI: 10.1016/j.jtos.2019.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/05/2019] [Accepted: 04/09/2019] [Indexed: 01/16/2023]
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31
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Abstract
PURPOSE Severe corneal disease contributes significantly to the global burden of blindness. Corneal allograft surgery remains the most commonly used treatment, but does not succeed long term in every patient, and the odds of success fall with each repeated graft. The Boston keratoprosthesis type I has emerged as an alternative to repeat corneal allograft. However, cost limits its use in resource-poor settings, where most corneal blind individuals reside. METHODS All aspects of the Boston keratoprosthesis design process were examined to determine areas of potential modification and simplification, with dual goals to reduce cost and improve the cosmetic appearance of the device in situ. RESULTS Minor modifications in component design simplified keratoprosthesis manufacturing. Proportional machinist time could be further reduced by adopting a single axial length for aphakic eyes, and a single back plate diameter. The cosmetic appearance was improved by changing the shape of the back plate holes from round to radial, with a petaloid appearance, and by anodization of back plate titanium to impute a more natural color. CONCLUSIONS We have developed a modified Boston keratoprosthesis type I, which we call the "Lucia." The Lucia retains the 2 piece design and ease of assembly of the predicate device, but would allow for manufacturing at a reduced cost. Its appearance should prove more acceptable to implanted patients. Successful keratoprosthesis outcomes require daily medications for the life of the patient and rigorous, frequent, postoperative care. Effective implementation of the device in resource-poor settings will require further innovations in eye care delivery.
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32
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Sacchetti M, Rama P, Bruscolini A, Lambiase A. Limbal Stem Cell Transplantation: Clinical Results, Limits, and Perspectives. Stem Cells Int 2018; 2018:8086269. [PMID: 30405723 DOI: 10.1155/2018/8086269] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 07/10/2018] [Accepted: 08/27/2018] [Indexed: 12/13/2022] Open
Abstract
Limbal stem cell deficiency (LSCD) is a clinical condition characterized by damage of cornea limbal stem cells, which results in an impairment of corneal epithelium turnover and in an invasion of the cornea by the conjunctival epithelium. In these patients, the conjunctivalization of the cornea is associated with visual impairment and cornea transplantation has poor prognosis for recurrence of the conjunctivalization. Current treatments of LSCD are aimed at replacing the damaged corneal stem cells in order to restore a healthy corneal epithelium. The autotransplantation of limbal tissue from the healthy, fellow eye is effective in unilateral LSCD but leads to depauperation of the stem cell reservoir. In the last decades, novel techniques such as cultivated limbal epithelial transplantation (CLET) have been proposed in order to reduce the damage of the healthy fellow eye. Clinical and experimental evidence showed that CLET is effective in inducing long-term regeneration of a healthy corneal epithelium in patients with LSCD with a success rate of 70%–80%. Current limitations for the treatment of LSCD are represented by the lack of a marker able to unequivocally identify limbal stem cells and the treatment of total, bilateral LSCD which requires other sources of stem cells for ocular surface reconstruction.
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