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Chang CY, Wang SSS, Lai YR, Koh WG, Wu JW, Chiang YH. Ophthalmic drug effects on the amyloidogenesis of a transforming growth factor β-induced protein (TGFBIp) peptide fragment. Exp Eye Res 2024; 244:109932. [PMID: 38762008 DOI: 10.1016/j.exer.2024.109932] [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: 11/05/2023] [Revised: 03/30/2024] [Accepted: 05/15/2024] [Indexed: 05/20/2024]
Abstract
Drugs that can treat one disease may either be detrimental or beneficial toward another due to possible cross-interactions. Therefore, care in choosing a suitable drug for patients with multiple diseases is crucial in successful patient management. This study explores several currently available ophthalmic drugs used to treat common ocular diseases to understand how they can affect the amyloidogenesis of a transforming growth factor β-induced protein (TGFBIp) peptide fragment found in abundance in the corneal protein aggregation deposits of lattice corneal dystrophy (LCD) patients. Results from this study provided supporting evidence that some drugs intended to treat other diseases can enhance or inhibit fibrillar aggregation of TGFBIp peptide, which may have potential implication of affecting the disease progression of LCD by either worsening or ameliorating it. Comparisons of the different properties of ophthalmic compounds explored in this study may also provide some guidance for future design of drugs geared toward the treatment of LCD.
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Affiliation(s)
- Chia-Yu Chang
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Steven S-S Wang
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - You-Ren Lai
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Won-Gun Koh
- Department of Chemical and Biomolecular Engineering, Yonsei University, South Korea
| | - Josephine W Wu
- Department of Optometry, Yuanpei University of Medical Technology, Hsinchu City, 30015, Taiwan; Department of Optometry, Mackay Medical College, New Taipei City, 252, Taiwan.
| | - Yi-Hui Chiang
- Department of Ophthalmology, En Chu Kong Hospital, New Taipei City, 237, Taiwan.
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Chang MS, Jun I, Kim EK. Mini-Review: Clinical Features and Management of Granular Corneal Dystrophy Type 2. KOREAN JOURNAL OF OPHTHALMOLOGY 2023; 37:340-347. [PMID: 37336511 PMCID: PMC10427907 DOI: 10.3341/kjo.2023.0032] [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: 03/17/2023] [Revised: 04/28/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023] Open
Abstract
Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant corneal stromal dystrophy that is caused by p.Arg124His mutation of transforming growth factor β induced (TGFBI) gene. It is characterized by well demarcated granular shaped opacities in central anterior stroma and as the disease progresses, extrusion of the deposits results in ocular pain due to corneal epithelial erosion. Also, diffuse corneal haze which appears late, causes decrease in visual acuity. The prevalence of GCD2 is high in East Asia including Korea. Homozygous patients show a severe phenotype from an early age, and the heterozygote phenotype varies among patients, depending on several types of compound heterozygous TGFBI mutations. In the initial stage, conservative treatments such as artificial tears, antibiotic eye drops, and bandage contact lenses are used to treat corneal erosion. Different surgical methods are used depending on the depth and extent of the stromal deposits. Phototherapeutic keratectomy removes anterior opacities and is advantageous in terms of its applicability and repeatability. For deeper lesions, deep anterior lamellar keratoplasty can be used as the endothelial layer is not always affected. Recurrence following these treatments are reported within a wide range of rates in different studies due to varying definition of recurrence and follow-up period. In patients who have undergone corneal laser vision-correction surgeries such as photorefractive keratectomy, LASEK, or LASIK including SMILE surgery, corneal opacity exacerbates rapidly with severe deterioration of visual acuity. Further investigations on new treatments of GCD2 are necessary.
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Affiliation(s)
- Myung Soo Chang
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul,
Korea
| | - Ikhyun Jun
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul,
Korea
- Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul,
Korea
| | - Eung Kweon Kim
- Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul,
Korea
- Saevit Eye Hospital, Goyang,
Korea
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3
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Choi EH, Suh S, Sears AE, Hołubowicz R, Kedhar SR, Browne AW, Palczewski K. Genome editing in the treatment of ocular diseases. Exp Mol Med 2023; 55:1678-1690. [PMID: 37524870 PMCID: PMC10474087 DOI: 10.1038/s12276-023-01057-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/14/2023] [Indexed: 08/02/2023] Open
Abstract
Genome-editing technologies have ushered in a new era in gene therapy, providing novel therapeutic strategies for a wide range of diseases, including both genetic and nongenetic ocular diseases. These technologies offer new hope for patients suffering from previously untreatable conditions. The unique anatomical and physiological features of the eye, including its immune-privileged status, size, and compartmentalized structure, provide an optimal environment for the application of these cutting-edge technologies. Moreover, the development of various delivery methods has facilitated the efficient and targeted administration of genome engineering tools designed to correct specific ocular tissues. Additionally, advancements in noninvasive ocular imaging techniques and electroretinography have enabled real-time monitoring of therapeutic efficacy and safety. Herein, we discuss the discovery and development of genome-editing technologies, their application to ocular diseases from the anterior segment to the posterior segment, current limitations encountered in translating these technologies into clinical practice, and ongoing research endeavors aimed at overcoming these challenges.
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Affiliation(s)
- Elliot H Choi
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA
| | - Susie Suh
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA
| | - Avery E Sears
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA
| | - Rafał Hołubowicz
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA
| | - Sanjay R Kedhar
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA
| | - Andrew W Browne
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA.
- Department of Physiology and Biophysics, University of California, Irvine, CA, USA.
- Department of Chemistry, University of California, Irvine, CA, USA.
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
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Ashena Z, Niestrata M, Tavassoli S. Management of Stromal Corneal Dystrophies; Review of the Literature with a Focus on Phototherapeutic Keratectomy and Keratoplasty. Vision (Basel) 2023; 7:vision7010022. [PMID: 36977302 PMCID: PMC10059954 DOI: 10.3390/vision7010022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/15/2023] Open
Abstract
Corneal dystrophies are a group of non-inflammatory inherited disorders of the cornea. This review considers treatment options for epithelial-stromal and stromal corneal dystrophies: namely Reis–Bücklers, Thiel–Behnke, lattice, Avellino, granular, macular and Schnyder corneal dystrophies. Where there is visual reduction, treatment options may include either phototherapeutic keratectomy (PTK) or corneal transplantation. Due to the anterior location of the deposits in Reis-Bücklers and Thiel–Behnke dystrophies, PTK is considered the treatment of choice. For lattice, Avellino, granular and macular corneal dystrophies, PTK provides temporary visual improvement; however, with recurrences, repeat PTK or a corneal transplant would be needed. For Schnyder dystrophy, should treatment be required, PTK may be the preferred option due to the potential for recurrence of the disease in corneal transplantation. This review discusses the literature and evidence base for the treatment of corneal dystrophies in terms of visual outcomes and recurrence rate.
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Affiliation(s)
- Zahra Ashena
- Ophthalmology Department, Queen’s Hospital, Barking, Havering and Redbridge University NHS Hospitals Trust, Romford RM7 0AG, UK
- Correspondence: ; Tel.: +01708-435000
| | - Magdalena Niestrata
- Moorfields Reading Centre and Clinical AI Hub, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- NIHR Biomedical Research Centre, UCL Institute of Ophthalmology, London EC1V 2PD, UK
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Compound heterozygous mutations in TGFBI cause a severe phenotype of granular corneal dystrophy type 2. Sci Rep 2021; 11:6986. [PMID: 33772078 PMCID: PMC7997986 DOI: 10.1038/s41598-021-86414-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/10/2021] [Indexed: 12/28/2022] Open
Abstract
We investigated the clinical and genetic features of patients with severe phenotype of granular corneal dystrophy type 2 (GCD2) associated with compound heterozygosity in the transforming growth factor-β-induced (TGFBI) gene. Patients with severe GCD2 underwent ophthalmic examination (best-corrected visual acuity test, intraocular pressure measurement, slit-lamp examination, and slit-lamp photograph analysis) and direct Sanger sequencing of whole-TGFBI. The patient’s family was tested to determine the pedigrees. Five novel mutations (p.(His174Asp), p.(Ile247Asn), p.(Tyr88Cys), p.(Arg257Pro), and p.(Tyr468*)) and two known mutations (p.(Asn544Ser) and p.(Arg179*)) in TGFBI were identified, along with p.(Arg124His), in the patients. Trans-phase of TGFBI second mutations was confirmed by pedigree analysis. Multiple, extensive discoid granular, and increased linear deposits were observed in the probands carrying p.(Arg124His) and other nonsense mutations. Some patients who had undergone phototherapeutic keratectomy experienced rapid recurrence (p.(Ile247Asn) and p.(Asn544Ser)); however, the cornea was well-maintained in a patient who underwent deep anterior lamellar keratoplasty (p.(Ile247Asn)). Thus, compound heterozygosity of TGFBI is associated with the phenotypic variability of TGFBI corneal dystrophies, suggesting that identifying TGFBI second mutations may be vital in patients with extraordinarily severe phenotypes. Our findings indicate the necessity for a more precise observation of genotype–phenotype correlation and additional care when treating TGFBI corneal dystrophies.
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Wang XR, Zhou BT, Zheng QM, Wang YD, Huang QK, Song X, Wang H, Zhang NW, Zhu YH, Chen XL, Yang JH. A recognition survey of granular corneal dystrophy type 2 genetic detection in China. Int J Ophthalmol 2020; 13:1976-1982. [PMID: 33344199 DOI: 10.18240/ijo.2020.12.20] [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: 10/17/2019] [Accepted: 04/07/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2 (GCD2) by a questionnaire conducted among citizens in five cities in China. METHODS The data were collected by questionnaire, and analyzed by Chi-square test and one-tailed t test in IBM SPSS statistics. RESULTS Based on the survey data on the awareness of GCD2 genetic detection in this study and the positive predictive analysis report of the citizens in five cities in China, the vast majority (84.2%) of respondents had never heard of it and did not know that GCD2 patients have been prohibited from performing excimer surgery that can deteriorate GCD2 patients' condition even leading to blindness. Though 3.4% of patients understood GCD2 very much, they have no idea that GCD2 could not be 100% accuracy diagnosed by the conventional inspection methods. CONCLUSION It is feasible and necessary to use GCD2 genetic detection as an excimer preoperative examination project. In order to promote the development of detection project, a few improvements should be carried out in terms of the promoting efforts, costs, and research progress.
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Affiliation(s)
- Xin-Rui Wang
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Bi-Ting Zhou
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Qing-Mei Zheng
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Ya-Duan Wang
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Qiu-Kai Huang
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Xuan Song
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - He Wang
- School of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, Fujian Province, China
| | - Nan-Wen Zhang
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Yi-Hua Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Xiao-Le Chen
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
| | - Ju-Hua Yang
- Department of Bioengineering and Biopharmaceutics, School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, China
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Mohammadi A, Ahmadi Shadmehri A, Taghavi M, Yaghoobi G, Pourreza MR, Tabatabaiefar MA. A pathogenic variant in the transforming growth factor beta I ( TGFBI) in four Iranian extended families segregating granular corneal dystrophy type II: A literature review. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2020; 23:1020-1027. [PMID: 32952948 PMCID: PMC7478261 DOI: 10.22038/ijbms.2020.36763.8757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 03/15/2020] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Granular and lattice corneal dystrophies (GCDs & LCDs) are autosomal dominant inherited disorders of the cornea. Due to genetic heterogeneity and large genes, unraveling the mutation is challenging. MATERIALS AND METHODS Patients underwent comprehensive clinical examination, and targeted next-generation sequencing (NGS) was used for mutation detection. Co-segregation and in silico analysis was accomplished. RESULTS Patients suffered from GCD. NGS disclosed a known pathogenic variant, c.371G>A (p.R124H), in exon 4 of TGFBI. The variant co-segregated with the phenotype in the family. Homozygous patients manifested with more severe phenotypes. Variable expressivity was observed among heterozygous patients. CONCLUSION The results, in accordance with previous studies, indicate that the c.371G>A in TGFBI is associated with GCD. Some phenotypic variations are related to factors such as modifier genes, reduced penetrance and environmental effects.
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Affiliation(s)
- Aliasgar Mohammadi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Azam Ahmadi Shadmehri
- Department of Genetics, Islamic Azad University, Science and Research Branch, Tehran, Iran
| | | | - Gholamhossein Yaghoobi
- Department of Ophthalmology, Birjand University of Medical Science, South Khorasan, Iran
- Social Detrimental Health Center, Birjand University of Medical Science, South Khorasan, Iran
| | - Mohammad Reza Pourreza
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
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8
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Lv Y, Li XJ, Wang HP, Liu B, Chen W, Zhang L. TGF-β1 enhanced myocardial differentiation through inhibition of the Wnt/β-catenin pathway with rat BMSCs. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2020; 23:1012-1019. [PMID: 32952947 PMCID: PMC7478252 DOI: 10.22038/ijbms.2020.42396.10019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 04/28/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To investigate and test the hypotheses that TGF-β1 enhanced myocardial differentiation through Wnt/β-catenin pathway with rat bone marrow mesenchymal stem cells (BMSCs). MATERIALS AND METHODS Lentiviral vectors carrying the TGF-β1 gene were transduced into rat BMSCs firstly. Then several kinds of experimental methods were used to elucidate the related mechanisms by which TGF-β1 adjusts myocardial differentiation in rat BMSCs. RESULTS Immunocytochemistry revealed that cTnI and Cx43 expressed positively in the cells that were transduced with TGF-β1. The results of Western blot (WB) test showed that the levels of intranuclear β-catenin and total β-catenin were all significantly decreased. However, the cytoplasmic β-catenin level was largely unchanged. Moreover, the levels of GSK-3β were largely unchanged in BMSCs, whereas phosphorylated GSK-3β was significantly decreased in BMSCs. When given the activator of Wnt/β-catenin pathway (lithium chloride, LiCl) to BMSCs transducted with TGF-β1, β-catenin was increased, while phosphorylated β-catenin was decreased. In addition, cyclinD1, MMP-7, and c-Myc protein in BMSCs transducted with Lenti-TGF-β1-GFP were significantly lower. CONCLUSION These results indicate that TGF-β1 promotes BMSCs cardiomyogenic differentiation by promoting the phosphorylation of β-catenin and inhibiting cyclinD1, MMP-7, and c-Myc expression in Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Yang Lv
- Department of Histology and Embryology, Hebei North University, Zhangjiakou, Hebei, China
- Department of Histology and Embryology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiu-juan Li
- Department of Histology and Embryology, Hebei North University, Zhangjiakou, Hebei, China
| | - Hai-Ping Wang
- Department of Histology and Embryology, Hebei North University, Zhangjiakou, Hebei, China
| | - Bo Liu
- Department of Pathology, the First Affiliated Hospital of Hebei North University, Zhangjiakou, Hebei, China
| | - Wei Chen
- Department of Pathology, the First Affiliated Hospital of Hebei North University, Zhangjiakou, Hebei, China
| | - Lei Zhang
- Department of Histology and Embryology, Hebei Medical University, Shijiazhuang, Hebei, China
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Lisch W, Weiss JS. Early and late clinical landmarks of corneal dystrophies. Exp Eye Res 2020; 198:108139. [PMID: 32726603 DOI: 10.1016/j.exer.2020.108139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 02/02/2023]
Abstract
Corneal dystrophies (CDs) represent a heterogenous group of genetic diseases (Lisch and Weiss, 2019). The International Committee of Classification of Corneal Dystrophies (IC3D) distinguishes between 22 distinct forms of corneal dystrophy (CD) which are predominantly autosomal dominant, although autosomal recessive and X-chromosomal dominant and recessive patterns do exist. A detailed corneal examination of as many affected family members as possible can show the phenotypic differences of the various generations. There are few publications which describe the different CDs with regard to the early and late phenotypes. According to early and late phenotype, three types of CD are generally classified: (1) Thirteen CDs with early and late clinical landmarks. However, it must be pointed out that the different penetrances of the gene often leads to quantitative differences in the corneal phenotype in peers in distinct generations of the same family. (2) Seven CDs with late onset and very little progression of the corneal changes. (3) Two CDs with congenital haze which can be interpreted as the final phenotype of this dystrophy. This applies to autosomal dominant and recessive inheritance.
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Affiliation(s)
- Walter Lisch
- Department of Ophthalmology, Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Jayne S Weiss
- Department of Ophthalmology, Pathology, and Pharmacology, Louisiana State University, School of Medicine, New Orleans, USA.
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10
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Kheir V, Cortés-González V, Zenteno JC, Schorderet DF. Mutation update: TGFBI pathogenic and likely pathogenic variants in corneal dystrophies. Hum Mutat 2019; 40:675-693. [PMID: 30830990 DOI: 10.1002/humu.23737] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 02/26/2019] [Accepted: 02/28/2019] [Indexed: 01/07/2023]
Abstract
Human transforming growth factor β-induced (TGFBI), is a gene responsible for various corneal dystrophies. TGFBI produces a protein called TGFBI, which is involved in cell adhesion and serves as a recognition sequence for integrins. An alteration in cell surface interactions could be the underlying cause for the progressive accumulation of extracellular deposits in different layers of the cornea with the resulting changes of refractive index and transparency. To this date, 69 different pathogenic or likely pathogenic variants in TGFBI have been identified in a heterozygous or homozygous state in various corneal dystrophies, including a novel variant reported here. All disease-associated variants were inherited as autosomal-dominant traits but one; this latter was inherited as an autosomal recessive trait. Most corneal dystrophy-associated variants are located at amino acids Arg124 and Arg555. To keep the list of corneal dystrophy-associated variant current, we generated a locus-specific database for TGFBI (http://databases.lovd.nl/shared/variants/TGFBI) containing all pathogenic and likely pathogenic variants reported so far. Non-disease-associated variants are described in specific databases, like gnomAD and ExAC but are not listed here. This article presents the most recent up-to-date list of disease-associated variants.
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Affiliation(s)
- Valeria Kheir
- Institute for Research in Ophthalmology, Sion, Switzerland.,Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Vianney Cortés-González
- Department of Genetics, Hospital "Dr. Luis Sanchez Bulnes", Asociación Para Evitar la Ceguera en México, Mexico City, Mexico
| | - Juan C Zenteno
- Department of Genetics, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico.,Department of Biochemistry, Faculty of Medicine, UNAM, Mexico City, Mexico
| | - Daniel F Schorderet
- Institute for Research in Ophthalmology, Sion, Switzerland.,Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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11
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Chao-Shern C, DeDionisio LA, Jang JH, Chan CC, Thompson V, Christie K, Nesbit MA, McMullen CBT. Evaluation of TGFBI corneal dystrophy and molecular diagnostic testing. Eye (Lond) 2019; 33:874-881. [PMID: 30760895 PMCID: PMC6707296 DOI: 10.1038/s41433-019-0346-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 12/10/2018] [Accepted: 12/29/2018] [Indexed: 12/04/2022] Open
Abstract
To date, 70 different TGFBI mutations that cause epithelial-stromal corneal dystrophies have been described. At present one commercially available test examines for the five most common of these mutations: R124H, R124C, R124L, R555W, and R555Q. To expand the capability of identifying the causative mutation in the remaining cases, 57 mutations would need to be added. The aim of this study was to obtain a better understanding of the worldwide distribution and population differences of TGFBI mutations and to assess which mutations could be included or excluded from any potential assay. A total of 184 published papers in Human Gene Mutation Database (HGMD) and PubMed from 34 countries worldwide reporting over 1600 corneal dystrophy cases were reviewed. Global data from 600,000 samples using the commercially available test were analyzed. Case studies by University College of London (UCL), Moorfield’s Corneal Dystrophy Study data and 19 samples from patients with clinical abnormality or uncertainty for which the current test detected no mutation were used to predict an achievable detection rate. Data from the literature search showed no difference in the spectrum and frequency of each mutation in different populations or geographical locations. According to our analysis, an increase to the worldwide detection rate in all populations from 75 to 90% could be achieved by the addition of six mutations—H626R, A546D, H572R, G623D, R124S, and M502V—to the currently available test and that may be beneficial for LASIK pre-screening worldwide.
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Affiliation(s)
- Connie Chao-Shern
- Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland, UK.,Avellino Lab USA, Inc., Menlo Park, CA, USA
| | | | | | - Clara C Chan
- Department of Ophthalmology, University of Toronto, Toronto, Canada
| | | | - Kathleen Christie
- Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland, UK
| | - M Andrew Nesbit
- Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland, UK.
| | - C B Tara McMullen
- Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland, UK
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12
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Siebelmann S, Scholz P, Sonnenschein S, Bachmann B, Matthaei M, Cursiefen C, Heindl LM. Anterior segment optical coherence tomography for the diagnosis of corneal dystrophies according to the IC3D classification. Surv Ophthalmol 2018; 63:365-380. [DOI: 10.1016/j.survophthal.2017.08.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/31/2017] [Accepted: 08/03/2017] [Indexed: 11/30/2022]
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Association Between Visual Acuity and the Corneal Area Occupied by Granular Lesions, Linear Lesions, or Diffuse Haze in Patients With Granular Corneal Dystrophy Type 2. Cornea 2018; 37:542-547. [PMID: 29443809 DOI: 10.1097/ico.0000000000001540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE In granular corneal dystrophy type 2 (GCD2), corneal deposits containing fragments of transforming growth factor-β-induced protein appear in sequence as granular lesions (GLs), linear lesions (LLs), and diffuse haze (DH). We aimed to investigate the association between visual acuity and age-related changes in lesion types in patients with GCD2. METHODS We retrospectively evaluated the medical records and slit-lamp photographs of 533 patients (1066 eyes) with genetically confirmed GCD2 (heterozygous). Deposits were classified into GLs, LLs, and DH, after which the area occupied by each lesion type was measured. The associations between visual acuity and each lesion area were also evaluated using univariable and multivariable models. RESULTS The area occupied by GLs increased beginning in the teen years, whereas the area occupied by DH began to increase after age 40. However, the area occupied by LLs increased until patients had reached their 40s, after which no further increases occurred. Multivariable analyses revealed no association between GLs and low visual acuity after adjusting for age and sex. Increases in the LL area were associated with lower odds for low visual acuity (adjusted odds ratio = 0.4 for the third tertile, 95% confidence interval, 0.2-0.97), whereas increases in the DH area were positively associated with low visual acuity (adjusted odds ratio = 3.3 for the third tertile of the DH area, 95% confidence interval, 1.3-8.3). CONCLUSIONS Our findings indicated that LLs associated with GCD2 do not produce significant decreases in visual acuity, whereas DH exerts the most significant negative impact on visual acuity. Late-onset DH may be associated with the termination of LL formation.
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Huerva V, Velasco A, Sánchez M, Matías-Guiu X. Role of BIGH3 R124H Mutation in the Diagnosis of Avellino Corneal Dystrophy. Eur J Ophthalmol 2018; 18:345-50. [DOI: 10.1177/112067210801800305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- V. Huerva
- Ophthalmology Department, University of Lleida, IRB-Lleida - Spain
| | - A. Velasco
- Pathology and Molecular Genetics Department, University Hospital Arnau de Vilanova, Lleida, University of Lleida, IRB-Lleida - Spain
| | - M.C. Sánchez
- Ophthalmology Department, University of Lleida, IRB-Lleida - Spain
| | - X. Matías-Guiu
- Pathology and Molecular Genetics Department, University Hospital Arnau de Vilanova, Lleida, University of Lleida, IRB-Lleida - Spain
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Repair of the TGFBI gene in human corneal keratocytes derived from a granular corneal dystrophy patient via CRISPR/Cas9-induced homology-directed repair. Sci Rep 2017; 7:16713. [PMID: 29196743 PMCID: PMC5711889 DOI: 10.1038/s41598-017-16308-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 11/06/2017] [Indexed: 01/08/2023] Open
Abstract
Granular corneal dystrophy (GCD) is an autosomal dominant hereditary disease in which multiple discrete and irregularly shaped granular opacities are deposited in the corneal stroma. GCD is caused by a point mutation in the transforming growth factor-β-induced (TGFBI) gene, located on chromosome 5q31. Here, we report the first successful application of CRISPR-Cas9-mediated genome editing for the correction of a TGFBI mutation in GCD patient-derived primary corneal keratocytes via homology-directed repair (HDR). To correct genetic defects in GCD patient cells, we designed a disease-specific guide RNA (gRNA) targeting the R124H mutation of TGFBI, which causes GCD type 2 (GCD2). An R124H mutation in primary human corneal keratocytes derived from a GCD2 patient was corrected by delivering a CRISPR plasmid expressing Cas9/gRNA and a single-stranded oligodeoxynucleotide HDR donor template in vitro. The gene correction efficiency was 20.6% in heterozygous cells and 41.3% in homozygous cells. No off-target effects were detected. These results reveal a new therapeutic strategy for GCD2; this method may also be applicable to other heredity corneal diseases.
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Pathogenesis and treatments of TGFBI corneal dystrophies. Prog Retin Eye Res 2015; 50:67-88. [PMID: 26612778 DOI: 10.1016/j.preteyeres.2015.11.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 11/22/2022]
Abstract
Transforming growth factor beta-induced (TGFBI) corneal dystrophies are a group of inherited progressive corneal diseases. Accumulation of transforming growth factor beta-induced protein (TGFBIp) is involved in the pathogenesis of TGFBI corneal dystrophies; however, the exact molecular mechanisms are not fully elucidated. In this review article, we summarize the current knowledge of TGFBI corneal dystrophies including clinical manifestations, epidemiology, most common and recently reported associated mutations for each disease, and treatment modalities. We review our current understanding of the molecular mechanisms of granular corneal dystrophy type 2 (GCD2) and studies of other TGFBI corneal dystrophies. In GCD2 corneal fibroblasts, alterations of morphological characteristics of corneal fibroblasts, increased susceptibility to intracellular oxidative stress, dysfunctional and fragmented mitochondria, defective autophagy, and alterations of cell cycle were observed. Other studies of mutated TGFBIp show changes in conformational structure, stability and proteolytic properties in lattice and granular corneal dystrophies. Future research should be directed toward elucidation of the biochemical mechanism of deposit formation, the relationship between the mutated TGFBIp and the other materials in the extracellular matrix, and the development of gene therapy and pharmaceutical agents.
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Development of a Transgenic Mouse with R124H Human TGFBI Mutation Associated with Granular Corneal Dystrophy Type 2. PLoS One 2015. [PMID: 26197481 PMCID: PMC4511001 DOI: 10.1371/journal.pone.0133397] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To investigate the phenotype and predisposing factors of a granular corneal dystrophy type 2 transgenic mouse model. METHODS Human TGFBI cDNA with R124H mutation was used to make a transgenic mouse expressing human protein (TGFBIR124H mouse). Reverse transcription PCR (RT-PCR) was performed to analyze TGFBIR124H expression. A total of 226 mice including 23 homozygotes, 106 heterozygotes and 97 wild-type mice were examined for phenotype. Affected mice were also examined by histology, immunohistochemistry and electron microcopy. RESULTS RT-PCR confirmed the expression of TGFBIR124H in transgenic mice. Corneal opacity defined as granular and lattice deposits was observed in 45.0% of homozygotes, 19.4% of heterozygotes. The incidence of corneal opacity was significantly higher in homozygotes than in heterozygotes (p = 0.02). Histology of affected mice was similar to histology of human disease. Lesions were Congo red and Masson Trichrome positive, and were observed as a deposit of amorphous material by electron microscopy. Subepithelial stroma was also stained with thioflavin T and LC3, a marker of autophagy activation. The incidence of corneal opacity was higher in aged mice in each group. Homozygotes were not necessarily more severe than heterozygotes, which deffers from human cases. CONCLUSIONS We established a granular corneal dystrophy type 2 mouse model caused by R124H mutation of human TGFBI. Although the phenotype of this mouse model is not equivalent to that in humans, further studies using this model may help elucidate the pathophysiology of this disease.
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Mazzotta C, Traversi C, Baiocchi S, Barabino S, Mularoni A. Phenotypic Spectrum of Granular Corneal Dystrophy Type II in Two Italian Families Presenting an Unusual Granular Corneal Dystrophy Type I Clinical Appearance. Case Rep Ophthalmol Med 2015; 2015:703418. [PMID: 26221553 PMCID: PMC4499619 DOI: 10.1155/2015/703418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 06/03/2015] [Indexed: 11/17/2022] Open
Abstract
Clinical, instrumental, and genetic findings are reported in Italian families with Type II Granular Corneal Dystrophies (GCD2) presenting an initial unusual presentation of a Granular Corneal Dystrophy Type I (GCD1) phenotypic spectrum in female descendants. Slit-lamp examinations showed the typical phenotypic features of GCD2 in both mothers and a phenotypic appearance of GCD1 in both daughters. Despite the different phenotypic onset, the genetic diagnostic testing revealed the presence of a mutation in the TGFB-I gene, typical of GCD2 in both cases, excluding GCD1. Patients who were clinically suspected of corneal dystrophy need a genetic confirmatory testing for certain diagnosis. Genetic test may help to find the specific mutation distinguishing between different phenotypic spectra with relative diagnostic and prognostic implications. The study demonstrates that the phenotypic spectrum of genetically confirmed granular corneal dystrophies in patients may change over time. Since the R124H mutation has also been described in clinically asymptomatic individuals prior to LASIK, who then develop dramatic deposition, suggesting that this particular mutation and phenotype may be sensitive to, precipitated, or modified by central cornea trauma, a careful familial anamnesis excluding cornel dystrophies and specific preoperative genetic test are recommended prior to LASIK.
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Affiliation(s)
- Cosimo Mazzotta
- Ophthalmic Operative Unit, Siena University Hospital, Viale Bracci, 53100 Siena, Italy
| | - Claudio Traversi
- Ophthalmic Operative Unit, Siena University Hospital, Viale Bracci, 53100 Siena, Italy
| | - Stefano Baiocchi
- Ophthalmic Operative Unit, Siena University Hospital, Viale Bracci, 53100 Siena, Italy
| | - Stefano Barabino
- Ophthalmic Operative Unit, Genoa University, Viale Benedetto XV, 16132 Genoa, Italy
| | - Alessandro Mularoni
- Department of Ophthalmology, Republic of San Marino Hospital, Via La Toscana, San Marino
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LASIK and surface ablation in corneal dystrophies. Surv Ophthalmol 2014; 60:115-22. [PMID: 25307289 DOI: 10.1016/j.survophthal.2014.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 08/15/2014] [Accepted: 08/19/2014] [Indexed: 11/22/2022]
Abstract
Corneal dystrophies are a rare group of hereditary disorders, that are bilateral, non-inflammatory, and progressive. Clinically, they can be classified based on the anatomic layer of the cornea affected. Refractive surgery and phototherapeutic keratectomy (PTK) can be performed with caution in patients with certain corneal dystrophies, but should be avoided in others. For epithelial basement membrane dystrophy, photorefractive keratectomy (PRK) is the procedure of choice for treatment of refractive error, and PTK may be performed for the treatment of recurrent erosions or irregular astigmatism. PRK and laser-assisted in situ keratomileusis (LASIK) have been associated with exacerbation of combined granular-lattice corneal dystrophy. LASIK and PRK appear to be safe in mild forms of posterior polymorphous corneal dystrophy, whereas LASIK should be avoided in Fuchs dystrophy. The safety of refractive surgery and PTK in the remainder of epithelial, Bowman layer, and stromal dystrophies has yet to be established.
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Lakshminarayanan R, Chaurasia SS, Anandalakshmi V, Chai SM, Murugan E, Vithana EN, Beuerman RW, Mehta JS. Clinical and genetic aspects of the TGFBI-associated corneal dystrophies. Ocul Surf 2014; 12:234-51. [PMID: 25284770 DOI: 10.1016/j.jtos.2013.12.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 12/05/2013] [Accepted: 12/05/2013] [Indexed: 11/16/2022]
Abstract
Corneal dystrophies are a group of inherited disorders localized to various layers of the cornea that affect corneal transparency and visual acuity. The deposition of insoluble protein materials in the form of extracellular deposits or intracellular cysts is pathognomic. Mutations in TGFBI are responsible for superficial and stromal corneal dystrophies. The gene product, transforming growth factor β induced protein (TGFBIp) accumulates as insoluble deposits in various forms. The severity, clinicopathogenic variations, age of the onset, and location of the deposits depend on the type of amino acid alterations in the protein. Until 2006, 38 different pathogenic mutants were reported for the TGFBI-associated corneal dystrophies. This number has increased to 63 mutants, reported in more than 30 countries. There is no effective treatment to prevent, halt, or reverse the deposition of TGFBIp. This review presents a complete mutation update, classification of phenotypes, comprehensive reported incidents of various mutations, and current treatment options and their shortcomings. Future research directions and possible approaches to inhibiting disease progression are discussed.
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Affiliation(s)
- R Lakshminarayanan
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore
| | - Shyam S Chaurasia
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Shu-Ming Chai
- Singapore Eye Research Institute, Singapore; Singapore National Eye Centre, Singapore
| | | | - Eranga N Vithana
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Roger W Beuerman
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore Eye Research Institute, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore National Eye Centre, Singapore; Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
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Abstract
PURPOSE The purpose of this case report is to review granular corneal dystrophy (GCD) and examine the new paradigm in its classification and treatment. CASE REPORT A 49-year-old white male patient reported yearly for monitoring of GCD. He had an ocular surgical history in the left eye for penetrating keratoplasty in 1989 and phototherapeutic keratectomy with mitomycin C for graft recurrence of stromal bread-crumb opacities 17+ years later in 2002. At his last examination, the patient's vision and comfort was stable in each eye, with minimal recurrence of granular opacities in the left surgical eye, stable granular opacities in the right eye, no recurrent corneal erosion symptoms in either eye, and best spectacle-corrected vision of 20/40 OD and 20/30 OS. CONCLUSIONS GCD is a Category 1, Stromal, TGFBI-associated corneal dystrophy. Although it is classified as a stromal dystrophy, research suggests the possibility that the granular opacities have an origination to the corneal epithelium with a migratory effect to the corneal stroma. Patients with Groenouw I, like the one in this report, usually do not have severely compromised vision. When vision is significantly affected or recurrent corneal erosion occurs, despite first- and second-line treatments, viable management options thereafter include photokeratectomy and other new surgical treatments such as femtosecond deep anterior lamellar keratoplasty and femtosecond laser-assisted keratoplasty. Future advancements in diagnostic technology, immunohistologic and genetic testing, medications, and surgery will allow for advancements in treating and managing patients with GCD.
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Abstract
PURPOSE To describe the characteristic features of white granular deposits associated with granular corneal dystrophy type 2 (GCD2). METHODS Five patients with GCD2 associated with the R124H mutation (2 homozygous GCD2 and 3 heterozygotes) were examined. The corneal deposits of all patients were assessed and reviewed by slit-lamp photographs. Density line profiles of corneal surfaces were evaluated around the discrete corneal deposits using Image J software. A Fourier-domain optical coherence tomography with cornea anterior module was used to visualize the characteristic surrounding features of these granular deposits. A histopathological study of the homozygous corneal specimen obtained after keratoplasty was performed. RESULTS Slit-lamp images and densitometry line profiles showed that discrete granules were surrounded by relatively clear areas in all patients. The Fourier-domain optical coherence tomography image clearly showed highly reflective lesions, corresponding to the corneal deposits, surrounded by lower reflective areas. Histopathological study revealed comparable findings to the optical coherence tomography image. Serial comparison of slit-lamp photographs demonstrated a recurrence pattern after penetrating keratoplasty in a homozygous patient and natural progression in a heterozygote patient. They were similar in that diffuse fine granules gradually increased in density and discrete granular deposits also enlarged or were newly formed. CONCLUSIONS In GCD2, discrete white granular deposits were surrounded by rather lucid areas and fine granular haze. These findings suggest that white granular deposits may be formed by aggregation of surrounding fine granules.
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Analysis of deposit depth and morphology in granular corneal dystrophy type 2 using fourier domain optical coherence tomography. Cornea 2011; 30:729-38. [PMID: 21242786 DOI: 10.1097/ico.0b013e3182000933] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Granular corneal dystrophy type 2 (GCD2) causes the formation of corneal deposits having 3 different morphological types. We used Fourier domain optical coherence tomography to assess the depths of each type according to the morphology. METHODS A prospective study was performed in 54 eyes of 54 heterozygous patients with GCD2. Corneal deposits of 54 patients with GCD2 were classified into 3 morphological types: type 1, diffuse haze; type 2, granular shape (2 subgroups: type 2a, round granulated and type 2b, round spiculated); and type 3, linear shape (2 subgroups: type 3a, short side branched and type 3b, long side branched). Using Fourier domain optical coherence tomography, we measured the distances from the Bowman layer to the upper surface of the deposits (USBL), to the lower surface of the deposits (LSBL), and the thickness of the deposits (TD). The deposits formed along the flap interface were also examined among 19 patients who had LASIK. RESULTS Types 1 and 2 deposits were always adjacent to the Bowman layer; thus the USBLs for each were 0.0 ± 0.0 μm, whereas that of type 3 deposits was 65.4 ± 48.0 μm (P < 0.0001). The LSBL and TD of linear deposits with long side branches (type 3) (313.3 ± 71.4 and 246.2 ± 71.9 μm) were greater than those of type 1 (47.7 ± 10.2 and 47.7 ± 10.2 μm) and type 2 (91.3 ± 39.5 and 91.3 ± 39.5 μm) (P < 0.0001). There were no differences in the measurements between the subgroups type 2a and type 2b or between types 3a and 3b. USBL of the laser in situ keratomileusis group was 54.5 ± 29.8 μm. CONCLUSIONS The depths of corneal deposits in patients with GCD2 were associated with the morphology of the deposits. The linear deposits were located most deeply in the cornea, followed by granular deposits and diffuse haze moving anteriorly. Several deposits have distinct depths according to the morphological types.
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Genotype of Lattice Corneal Dystrophy (R124C Mutation in TGFBI) in a Patient Presenting With Features of Avellino Corneal Dystrophy. Cornea 2011; 30:949; author reply 949-50. [DOI: 10.1097/ico.0b013e3182031e5c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kim TI, Kim H, Lee DJ, Choi SI, Kang SW, Kim EK. Altered mitochondrial function in type 2 granular corneal dystrophy. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:684-92. [PMID: 21699880 DOI: 10.1016/j.ajpath.2011.04.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 03/15/2011] [Accepted: 04/18/2011] [Indexed: 12/31/2022]
Abstract
Type 2 granular corneal dystrophy (GCD2) is caused by point mutation R124H in the transforming growth factor-β-induced gene (TGFBI) and is characterized by age-dependent progression of corneal deposits. Mitochondrial features in heterozygous GCD2 and normal corneal tissues was evaluated using electron microscopy. Primary corneal fibroblasts of homozygous and normal corneas were cultured to passage 4 or 8. Keratocytes of normal corneal tissue are narrow, and details of their intracellular organelles are difficult to distinguish. Keratocytes of heterozygous GCD2 tissues exhibited many degenerative mitochondria. MitoTracker and cytochrome c staining demonstrated increased mitochondrial activity in mutated cells at early passages. Decreases in depolarized mitochondria, cellular proliferation, and expression of complexes I to V and increases in apoptotic change were observed in late-passage mutant fibroblasts. PGC-1α, ANT-1, p-Akt, and p-mTOR but not NF-κB expression demonstrated a passage-dependent decrease in all cells. Increased passage- or mutation-related intracellular reactive oxygen species and delayed proliferation of methanethiosulfonate (MTS) were recovered using application of antioxidant butylated hydroxyanisole. Mitochondrial features and function were altered in mutated GCD2 keratocytes, in particular in older cells. Alteration of mitochondrial function is critical for understanding the pathogenesis of GCD2.
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Affiliation(s)
- Tae-im Kim
- Corneal Dystrophy Research Institute, the Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea
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Abstract
PURPOSE Both granular and lattice deposits are present in Avellino corneal dystrophy (ACD), primarily associated with the R124H mutation of transforming growth factor-β-induced (TGFBIp). We investigated the presence of these deposits in other TGFBI mutations and the use of Thioflavin-T (ThT), a fluorescent amyloid stain for characterizing corneal amyloid deposits. METHODS Surgical corneal specimens of 3 unrelated patients clinically diagnosed with ACD were studied. Corneal sections from normal individuals and patients with prior lattice corneal dystrophy (LCD) were used as controls. Histochemical studies were performed with Congo red and Masson trichrome stains, and fluorescent imaging with scanning laser confocal microscopy was performed for ThT and anti-TGFBIp antibody staining. RESULTS Clinical and histopathological findings supported the diagnoses of ACD in these 3 cases in whom granular deposits stained with Masson trichrome and lattice deposits stained with ThT and Congo red showed birefringence and dichroism as expected. However, genotyping revealed a heterozygous R124C mutation in each case. In addition to classical stromal deposits, unique subepithelial TGFBIp aggregates, which stain with neither ThT nor trichrome, were observed. In control LCD sections, stromal deposits were stained with ThT but not with trichrome, confirming lack of granular deposits. CONCLUSIONS Our results demonstrate that both granular and lattice corneal deposits can be associated with R124C mutation in addition to the more common R124H mutation. An additional feature of nonhyaline, nonamyloid, TGFBIp subepithelial deposits might substantiate the categorization of such cases as a variant form of ACD. This study further validates ThT staining for detection of amyloid TGFBIp deposits.
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Molecular Genetics of Corneal Disease. Cornea 2011. [DOI: 10.1016/b978-0-323-06387-6.00019-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lee JH, Cristol SM, Kim WC, Chung ES, Tchah H, Kim MS, Nam CM, Cho HS, Kim EK. Prevalence of granular corneal dystrophy type 2 (Avellino corneal dystrophy) in the Korean population. Ophthalmic Epidemiol 2010; 17:160-5. [PMID: 20455845 DOI: 10.3109/09286581003624939] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE This study investigates the prevalence of granular corneal dystrophy type 2 (GCD2; Avellino corneal dystrophy) in the Korean population. METHODS GCD2 homozygotes were identified through a collaboration of Korean referral centers for corneal disease. The genetic status of the patients and their immediate families were verified by DNA analysis. A lower bound for the gene prevalence was calculated using a model based on the Hardy-Weinberg principle. A second population-based model was developed to correct for known underestimation in the primary model. The corrected model used population data from the 2005 Korean census and fertility rates from historical Korean census data. RESULTS We identified 21 individuals homozygous for GCD2 (R124H mutation) from 16 Korean families. From this, we estimate that the overall prevalence (combining heterozygotes and homozygotes) is at least 8.25 affected persons/10,000 persons. Our corrected estimate for overall prevalence is 11.5 affected persons/10,000 persons. CONCLUSION We present the first estimate of the prevalence of GCD2. Although uncommon, the prevalence of GCD2 in Korea is greater than anticipated. We believe that our approach could potentially be applied to estimating the prevalence of other rare diseases.
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Affiliation(s)
- Jae Hwan Lee
- Corneal Dystrophy Research Institute, Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
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Mitomycin C Does Not Inhibit Exacerbation of Granular Corneal Dystrophy Type II Induced by Refractive Surface Ablation. Cornea 2010; 29:490-6. [DOI: 10.1097/ico.0b013e3181c3258a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dalton K, Schneider S, Sorbara L, Jones L. Confocal microscopy and optical coherence tomography imaging of hereditary granular dystrophy. Cont Lens Anterior Eye 2009; 33:33-40. [PMID: 19945908 DOI: 10.1016/j.clae.2009.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Revised: 09/26/2009] [Accepted: 09/30/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVES This case report examines the clinical characteristics of hereditary granular dystrophy through the use of slit lamp digital photography, confocal microscopy (CM) and optical coherence tomography (OCT). A review of the literature describing the histopathological and genetic associations of stromal dystrophies, suggest it may be possible to differentiate dystrophies based on their clinical manifestations, and appearances of CM and OCT images, with or without the use of genetic testing. CASE REPORT Two sisters, previously diagnosed with Granular (Groenouw I) Dystrophy, were examined. Examination included the use of digital slit lamp photography, CM and OCT imaging. RESULTS "Breadcrumb" opacities were visualized in the anterior two-thirds of the stroma with all three imaging techniques. Opacities were demonstrated in the posterior third of the stroma with the digital photography and OCT techniques. CONCLUSIONS The digital photography, CM and OCT images support the sister's diagnosis of Granular (Groenouw I) Dystrophy. Currently, genetic and histopathological testing are the only techniques available to determine exactly which corneal dystrophy and gene mutation are present. The results of this case report demonstrate that slit lamp digital photography, combined with CM and OCT may be capable of providing sufficient diagnostic information to diagnose corneal granular dystrophies in a clinical setting.
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Affiliation(s)
- Kristine Dalton
- School of Optometry, University of Waterloo, Ontario, Canada.
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Genetic associations of common deletion polymorphisms in families with Avellino corneal dystrophy. Biochem Biophys Res Commun 2009; 387:688-93. [DOI: 10.1016/j.bbrc.2009.07.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Accepted: 07/16/2009] [Indexed: 01/22/2023]
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Femtosecond-Assisted Lamellar Keratoplasty in Atypical Avellino Corneal Dystrophy of Indian Origin. Eye Contact Lens 2009; 35:272-4. [DOI: 10.1097/icl.0b013e3181b3859c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
In recent years, our laboratory has used lectins to detect carbohydrate-related abnormalities in dystrophic corneas and species-specific differences in the carbohydrates of normal corneas. These studies have: 1) demonstrated that abnormal glycoconjugates are present in corneas with macular and lattice dystrophy, 2) provided additional means of differentiating corneas with macular, lattice and granular dystrophy, 3) demonstrated that distinct species-specific differences are present in the glycoconjugates of normal corneas and 4) provided guidelines for the selection of an animal model for the study of corneal glycoconjugates.
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Affiliation(s)
- N Panjwani
- Department of Ophthalmology, Tufts University School of Medicine, Boston, MA
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Wiggs JL. Molecular Genetics of Selected Ocular Disorders. Ophthalmology 2009. [DOI: 10.1016/b978-0-323-04332-8.00002-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Weiss JS, Møller HU, Lisch W, Kinoshita S, Aldave AJ, Belin MW, Kivelä T, Busin M, Munier FL, Seitz B, Sutphin J, Bredrup C, Mannis MJ, Rapuano CJ, Van Rij G, Kim EK, Klintworth GK. The IC3D classification of the corneal dystrophies. Cornea 2008; 27 Suppl 2:S1-83. [PMID: 19337156 PMCID: PMC2866169 DOI: 10.1097/ico.0b013e31817780fb] [Citation(s) in RCA: 195] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The recent availability of genetic analyses has demonstrated the shortcomings of the current phenotypic method of corneal dystrophy classification. Abnormalities in different genes can cause a single phenotype, whereas different defects in a single gene can cause different phenotypes. Some disorders termed corneal dystrophies do not appear to have a genetic basis. PURPOSE The purpose of this study was to develop a new classification system for corneal dystrophies, integrating up-to-date information on phenotypic description, pathologic examination, and genetic analysis. METHODS The International Committee for Classification of Corneal Dystrophies (IC3D) was created to devise a current and accurate nomenclature. RESULTS This anatomic classification continues to organize dystrophies according to the level chiefly affected. Each dystrophy has a template summarizing genetic, clinical, and pathologic information. A category number from 1 through 4 is assigned, reflecting the level of evidence supporting the existence of a given dystrophy. The most defined dystrophies belong to category 1 (a well-defined corneal dystrophy in which a gene has been mapped and identified and specific mutations are known) and the least defined belong to category 4 (a suspected dystrophy where the clinical and genetic evidence is not yet convincing). The nomenclature may be updated over time as new information regarding the dystrophies becomes available. CONCLUSIONS The IC3D Classification of Corneal Dystrophies is a new classification system that incorporates many aspects of the traditional definitions of corneal dystrophies with new genetic, clinical, and pathologic information. Standardized templates provide key information that includes a level of evidence for there being a corneal dystrophy. The system is user-friendly and upgradeable and can be retrieved on the website www.corneasociety.org/ic3d.
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Affiliation(s)
- Jayne S Weiss
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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Lee JH, Stulting RD, Lee DH, Lee CS, Kim WC, Kim EK. Exacerbation of granular corneal dystrophy type II (Avellino corneal dystrophy) after LASEK. J Refract Surg 2008; 24:39-45. [PMID: 18269147 DOI: 10.3928/1081597x-20080101-06] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To report cases of granular corneal dystrophy type II (Avellino corneal dystrophy) that were exacerbated by uncomplicated laser epithelial keratomileusis (LASEK) for myopia. METHODS Eight patients (15 eyes) with granular corneal dystrophy type II who underwent LASEK were examined by DNA sequencing, slit-lamp microscopy, and confocal microscopy. RESULTS The number and density of the opacities increased after LASEK. Best spectacle-corrected visual acuity decreased after LASEK as the density of the opacities increased. In three patients, mitomycin C was used intraoperatively, but corneal deposits also worsened in these patients. CONCLUSIONS LASEK is contraindicated in patients with granular corneal dystrophy type II because vision may be reduced from an increase in the density of corneal opacities postoperatively.
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Affiliation(s)
- Jae Hwan Lee
- Department of Ophthalmology, Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul, Korea
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Awwad ST, Di Pascuale MA, Hogan RN, Forstot SL, McCulley JP, Cavanagh HD. Avellino corneal dystrophy worsening after laser in situ keratomileusis: further clinicopathologic observations and proposed pathogenesis. Am J Ophthalmol 2008; 145:656-61. [PMID: 18243154 DOI: 10.1016/j.ajo.2007.12.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 12/03/2007] [Accepted: 12/05/2007] [Indexed: 11/30/2022]
Abstract
PURPOSE To study the nature of the deposits in Avellino corneal dystrophy (ACD) worsening after laser in situ keratomileusis (LASIK), and suggest a mechanism for histopathogenesis. DESIGN Interventional case report. METHODS A 28-year-old woman previously diagnosed with bilateral ACD underwent bilateral LASIK. The corneal dystrophy progressively worsened bilaterally, one year later. A penetrating keratoplasty was subsequently performed on the right eye at 31 years of age, and in the left eye a year later. The clinical and histopathologic findings of the corneal graft of the right eye were reported in the literature, with positivity to the Masson trichrome stain, negative staining with Congo red, and heterozygosity for the Arg124His mutation by serum DNA studies. Histopathologic studies of the corneal graft of the left eye were conducted at the University of Texas Southwestern Medical Center. RESULTS Histopathologic examination of the excised cornea showed the Masson trichrome positive deposits present from underneath the Bowman layer to the LASIK interface, with absence of deposits posterior to the latter. In contrast to the prior report describing findings in the corneal graft of the left eye, the deposits stained lightly with Congo red, but failed to show birefringence under polarized light, or fluorescence with thioflavin T. CONCLUSION Accelerated deposits developing after LASIK in ACD eyes seem to harbor pre-amyloid features. The epithelium is likely to be the culprit, in a pathway independent of with human transforming growth hormone beta (TGF-beta), with deposits developing in the anterior stroma and the stromal interface.
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Affiliation(s)
- Shady T Awwad
- Cornea, External Diseases, and Refractive Surgery, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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Alavi A, Elahi E, Rahmati-Kamel M, Karimian F, Rezaei-Kanavi M. Mutation screening of TGFBI in two Iranian Avellino corneal dystrophy pedigrees. Clin Exp Ophthalmol 2008; 36:26-30. [PMID: 18290950 DOI: 10.1111/j.1442-9071.2007.01649.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Genetic analysis and phenotypic features of Avellino corneal dystrophy patients from Japan and some European countries have been published. We report for the first time the genetic analysis and phenotypic features of two Avellino corneal dystrophy pedigrees from the Middle East. METHODS Slit-lamp biomicroscope photographs of cornea were obtained, and corneal tissue sections were stained with masson-trichrome and Congo red. DNA was isolated from peripheral blood leucocytes and exons 4 and 12 of TGFBI were screened for mutations by direct sequencing. RESULTS The probands of the pedigrees had phenotypic features consistent with diagnosis of Avellino corneal dystrophy. They were homozygous for the same R124H mutation in TGFBI as previously reported in Avellino patients from Japan and European countries. Heterozygous carriers of the mutation were identified in the pedigree and shown to have symptoms of disease milder than those of the probands. CONCLUSION The finding of R124H in the Middle Eastern (Iranian) population supports the proposal that perhaps only substitution of histidine for arginine at position 124 of tumour growth factor beta induced protein results in the Avellino corneal dystrophy phenotype. As both probands were originally diagnosed with granular corneal dystrophy, and as heterozygous carriers of R124H were unaware of their disease status prior to genetic analysis, the importance of genetic analysis is emphasized.
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Affiliation(s)
- Afagh Alavi
- National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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Deposits of transforming growth factor-beta-induced protein in granular corneal dystrophy type II after LASIK. Cornea 2008; 27:28-32. [PMID: 18245963 DOI: 10.1097/ico.0b013e318156d36d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To analyze components of the deposits in the corneal flap interface of granular corneal dystrophy type II (GCD II) patients after laser in situ keratomileusis (LASIK). METHODS Four corneal GCD II specimens displaying disease exacerbation after LASIK were analyzed. Three of these specimens included the recipient corneal button after penetrating keratoplasty or deep lamellar keratoplasty for advanced GCD II after LASIK. The fourth specimen, a similar case of GCD II after LASIK, included the amputated corneal flap. Specimens were processed for histopathologic and immunohistochemical analyses. RESULTS Corneal stromal deposits in the LASIK flaps of all specimens were stained with 3 anti-transforming growth factor-beta-induced protein (TGFBIp) antibodies. The deposits displayed bright red color staining with Masson trichrome; however, negative staining was seen with Congo red, suggesting that hyaline is the main component localizing to the TGFBIp deposits rather than amyloid. CONCLUSIONS Amorphous granular material deposited along the interface of the LASIK flap in GCD II corneas is composed mainly of hyaline deposits.
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Park KA, Ki CS, Chung ES, Chung TY. Deep Anterior Lamellar Keratoplasty in Korean Patients With Avellino Dystrophy. Cornea 2007; 26:1132-5. [PMID: 17893551 DOI: 10.1097/ico.0b013e318123765b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the surgical outcome of deep anterior lamellar keratoplasty (DALK) in Korean patients with Avellino dystrophy. METHODS A retrospective study was performed in 4 eyes (4 patients) with recurrent Avellino dystrophy after phototherapeutic keratectomy (PTK). Genetic study was performed on 2 patients to confirm the diagnosis. Partial-thickness donor cornea (devoid of endothelium and Descemet membrane) was transplanted onto a recipient bed after deep lamellar dissection and removal of recipient stroma. Visual acuity, refractive error, keratometry values, topographic astigmatism, and complications were evaluated after a follow-up period of at least 14 months. RESULTS The mean age of the patients was 52.5 +/- 3.32 years, and the mean follow-up period was 17.5 +/- 3.11 months. Visual acuity was improved to > or = 20/25 in all cases. Postoperative topographic astigmatism ranged from 1.2 to 4.9 D. In 1 case, double anterior chamber developed after the operation, which resolved after gas injection into the anterior chamber. During the follow-up period, there were no signs of graft rejection, and all grafts were transparent except one, in which small opacity recurred in the peripheral corneal stroma 13 months postoperatively. CONCLUSIONS DALK is considered a good primary surgical option in patients with recurrent Avellino dystrophy after PTK.
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Affiliation(s)
- Kyung-Ah Park
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Lee WB, Himmel KS, Hamilton SM, Zhao XC, Yee RW, Kang SJ, Grossniklaus HE. Excimer laser exacerbation of Avellino corneal dystrophy. J Cataract Refract Surg 2007; 33:133-8. [PMID: 17189809 DOI: 10.1016/j.jcrs.2006.09.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Accepted: 08/14/2006] [Indexed: 11/18/2022]
Abstract
We review the clinical, histopathological, and ultrastructural findings and DNA phenotyping of a patient with Avellino corneal dystrophy exacerbated by laser in situ keratomileusis. The findings are reported and interpreted in the context of a literature review. The case highlights the possible difficulty of recognizing subtle dystrophic findings, as well as the importance of avoiding refractive surgical intervention in patients with Avellino corneal dystrophy to avoid exacerbation of dystrophic deposits in the cornea and subsequent reduction in vision.
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Affiliation(s)
- W Barry Lee
- Cornea, External Disease and Refractive Surgery Section, Emory University School of Medicine, Atlanta, Georgia, USA.
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Tsujikawa K, Tsujikawa M, Watanabe H, Maeda N, Inoue Y, Fujikado T, Tano Y. Allelic homogeneity in Avellino corneal dystrophy due to a founder effect. J Hum Genet 2006; 52:92-97. [PMID: 17096061 DOI: 10.1007/s10038-006-0083-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Accepted: 10/16/2006] [Indexed: 11/30/2022]
Abstract
Avellino corneal dystrophy (ACD) is a common corneal dystrophy that shows allelic homogeneity, R124H mutation in the transforming growth factor beta-induced (TGFBI) gene. There are distinct phenotypes of homozygous Avellino corneal dystrophy, termed types I and II. To investigate if the difference is caused by a modifier mutation, we sequenced the entire coding region of TGFBI of two types of ACDs. The sequences obtained from each type were identical, and we could not find any nucleotide alternations. Instead, we found seven single nucleotide polymorphisms (SNPs) compared with the normal control. Primer extension analysis revealed that all 14 homozygous patients were homozygotes in each SNP, which meant that all the patients shared the same disease haplotype. Subsequent analysis of 45 heterozygous ACD patients showed strong linkage disequilibrium between disease alleles of each SNP and ACD. These results strongly suggest that the allelic homogeneity of TGFBI associated corneal dystrophies (ACD, lattice corneal dystrophy types I and III, granular corneal dystrophy and Reis-Bucklers dystrophy) might not be caused by mutation hot spots but by the founder effects.
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Affiliation(s)
- Kaoru Tsujikawa
- Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka Suita, Osaka, Japan
| | - Motokazu Tsujikawa
- Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka Suita, Osaka, Japan.
| | - Hitoshi Watanabe
- Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka Suita, Osaka, Japan
| | - Naoyuki Maeda
- Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka Suita, Osaka, Japan
| | - Yoshitsugu Inoue
- Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka Suita, Osaka, Japan
| | - Takashi Fujikado
- Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka Suita, Osaka, Japan
| | - Yasuo Tano
- Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka Suita, Osaka, Japan
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Abstract
PURPOSE OF REVIEW Major advances and developments in corneal molecular genetics have revolutionized our fundamental understanding of corneal dystrophies. At the same time, this knowledge is allowing for improved ways to classify these dystrophies. New genes and mutations responsible for corneal dystrophies are being discovered at an accelerating rate. Ophthalmologists must keep abreast of all the new information, as our basic understanding as well as our classification systems are changing. We present a current review of the genetics of corneal dystrophies. RECENT FINDINGS After the discovery of the BIGH3 (TGFbeta1) gene responsible for several corneal dystrophies, there has been an explosion of new information. New mutations are discovered every day for many of the corneal dystrophies located on the BIGH3 gene. In addition, new genetic sites are also being realized. Additionally, corneal dystrophies which have never been linked to any genetic site are now beginning to be uncovered. SUMMARY As new mutations and genetic sites are discovered for the various corneal dystrophies, new information will arise, allowing researches to develop innovative methods to study these gene products and their function. This will open the door for novel diagnostic and therapeutic approaches. Ultimately, gene therapy may be possible, leading to cures for these sight-threatening diseases.
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Affiliation(s)
- Sean F Pieramici
- Duke University Eye Center, Duke University Medical Center, Durham, North Carolina 27705, USA
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Abstract
The lattice corneal dystrophies (LCD) and granular corneal dystrophies (GCD) are autosomal dominant disorders of the corneal stroma. They are bilateral, progressive conditions characterized by the formation of opacities arising due to the deposition of insoluble material in the corneal stroma leading to visual impairment. The LCDs and GCDs are distinguished from each other and are divided into subtypes on the basis of the clinical appearance of the opacities, clinical features of the disease, and on histopathological staining properties of the deposits. The GCDs and most types of LCD arise from mutations in the transforming growth factor beta-induced (TGFBI) gene on chromosome 5q31. Over 30 mutations causing LCD and GCD have been identified so far in the TGFBI. There are two mutation hotspots corresponding to arginine residues at positions 124 and 555 of the transforming growth factor beta induced protein (TGFBIp) and they are the most frequent sites of mutation in various populations. Mutations at either of these two hotspots result in specific types of LCD or GCD. The majority of identified mutations involve residues in the fourth fasciclin-like domain of TGFBIp.
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Affiliation(s)
- Chitra Kannabiran
- Kallam Anji Reddy Molecular Genetics Laboratory, L.V. Prasad Eye Institute, Hyderabad, India.
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Abstract
Over the past decade, there has been an exponential increase in our knowledge of heritable eye conditions. Coincidentally, our ability to provide accurate genetic diagnoses has allowed appropriate counseling to patients and families. A summary of our current understanding of ocular genetics will prove useful to clinicians, researchers, and students as an introduction to the subject.
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Affiliation(s)
- Ian M MacDonald
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada
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Diaper CJM, Schorderet DF, Chaubert P, Munier FL. Clinical and immunopathological corneal phenotype in homozygotes for the BIGH3 R124H mutation. Eye (Lond) 2004; 19:92-6. [PMID: 15094731 DOI: 10.1038/sj.eye.6701398] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A family was previously reported as suffering from severe granular dystrophy. The phenotypic picture suggested a mix of homozygous and heterozygous family members. Genetic analysis confirms the homozygousity in the patients most severely affected, but shows the disease state to be one of Avellino corneal dystrophy. The previous case reports are extended immunohistological staining using polyclonal antibodies raised against keratofepithelin. This genotype/phenotype correlation study is consistent with incomplete dominance.
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Affiliation(s)
- C J M Diaper
- Southern General Hospital, 1345 Govan Road, Glasgow G51 4TF UK
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50
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El-Ashry MF, Abd El-Aziz MM, Larkin DFP, Clarke B, Cree IA, Hardcastle AJ, Bhattacharya SS, Ebenezer ND. A clinical, histopathological, and genetic study of Avellino corneal dystrophy in British families. Br J Ophthalmol 2003; 87:839-42. [PMID: 12812879 PMCID: PMC1771747 DOI: 10.1136/bjo.87.7.839] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To establish a clinical, histopathological, and genetic diagnosis in two unrelated British families with Avellino corneal dystrophy (ACD). METHODS Genomic DNA was extracted from peripheral blood leucocytes of all members participating in the study. Exons 4 and 12 of the human transforming growth factor beta induced (BIGH3) gene were amplified by polymerase chain reaction. The mutation and polymorphism were identified by direct sequencing and restriction digest analysis. A review of the patients' clinical symptoms and signs was undertaken and a histopathological study on corneal specimen obtained from the proband of one family after keratoplasty was performed. RESULTS A heterozygous G to A transition at the second nucleotide position of codon 124 of BIGH3 gene was detected in all affected members of both families. This mutation changes an arginine residue to a histidine. The clinical diagnosis for ACD was more evident with advancing age. Histopathological study revealed granular deposits in the anterior stroma and occasional positive Congo red areas of amyloid deposition in the mid to deep stroma typical of ACD. CONCLUSIONS This is the first report of ACD families in the United Kingdom and, furthermore, of BIGH3 gene mutation in British patients with this rare type of corneal dystrophy. The results indicate that BIGH3 gene screening along with clinical and histopathological examinations is essential for the diagnosis and clinical management of corneal dystrophies.
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Affiliation(s)
- M F El-Ashry
- Department of Molecular Genetics, Institute of Ophthalmology, London EC1V 9EL, UK.
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