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Xu L, Zheng X, Yin S, Yang K, Fan Q, Gu Y, Yuan Y, Yin C, Zang Y, Pang C, Sun L, Ren S. Association of Novel Loci With Keratoconus Susceptibility in a Chinese Genome-Wide Association Study. Invest Ophthalmol Vis Sci 2024; 65:29. [PMID: 38767907 PMCID: PMC11114610 DOI: 10.1167/iovs.65.5.29] [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: 02/17/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024] Open
Abstract
Purpose Keratoconus (KC) is a progressive corneal disease that can lead to corneal blindness if not properly managed. The purpose of this study was to identify genetic associations with KC in China and to investigate whether these genetic variants are associated with corneal thickness and corneal curvature in KC cases. Methods A genome-wide association study was conducted on 853 patients with KC and 6248 controls. The KC cases were genotyped with the Illumina Infinium Human Asian Screening Array BeadChip, and the controls were genotyped with the Illumina Infinium Human Global Screening Array BeadChip. Genetic associations with KC, as well as correlations between the positive variants and corneal parameters including central corneal thickness (CCT) and mean keratometry (Km), were compared using PLINK version 1.90. Results Our present study identified four single-nucleotide polymorphisms (SNPs) within four risk loci (PTGER3: rs2300163, EYA1: rs1077435, ASS1: rs141365191, and CHTF8: rs3743680) associated with KC in Chinese patients that reached genome-wide significance. Among the identified SNPs with P < 1.00 × 10-4, seven SNPs (FOSL2-PLB1: rs12622211, RXRA-COL5A1: rs3118515, rs3132306, rs1536482, rs3118520, KAT6B: rs192187772, RAP2A-IPO5: rs41361245) were observed to be associated with CCT, and one SNP (USP13: rs6767552) was found to be associated with Km. Conclusions In the first genome-wide association study of KC with a relatively large study population in China, we identified four SNPs in four risk loci associated with the disease. The findings enriched the understanding of genetic susceptibility to KC and provided new insights into the genetic etiology of the disease.
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Affiliation(s)
- Liyan Xu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
- Eye Institute, Henan Academy of Innovations in Medical Science, Zhengzhou, China
| | - Xiaodong Zheng
- Department of Dermatology, the First Affiliated Hospital of Anhui Medical University, Hefei, China
- Key Laboratory of Dermatology (Anhui Medical University), Ministry of Education, Hefei, China
| | - Shanshan Yin
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, Zhengzhou, China
| | - Kaili Yang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
- Eye Institute, Henan Academy of Innovations in Medical Science, Zhengzhou, China
| | - Qi Fan
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Yuwei Gu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Yi Yuan
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, Zhengzhou, China
| | - Chenchen Yin
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, Zhengzhou, China
| | - Yonghao Zang
- Xinxiang Medical University, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, Zhengzhou, China
| | - Chenjiu Pang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Liangdan Sun
- Department of Dermatology, North China University of Science and Technology Affiliated Hospital Tangshan, China
- School of Public Health, North China University of Science and Technology, Tangshan, China
| | - Shengwei Ren
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
- Eye Institute, Henan Academy of Innovations in Medical Science, Zhengzhou, China
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Kondkar AA, Azad TA, Sultan T, Khatlani T, Alshehri AA, Lobo GP, Kalantan H, Al-Obeidan SA, Al-Muammar AM. Association between Polymorphism rs61876744 in PNPLA2 Gene and Keratoconus in a Saudi Cohort. Genes (Basel) 2023; 14:2108. [PMID: 38136930 PMCID: PMC10742661 DOI: 10.3390/genes14122108] [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: 09/12/2023] [Revised: 11/05/2023] [Accepted: 11/17/2023] [Indexed: 12/24/2023] Open
Abstract
The genetic etiology of Keratoconus (KC) in Middle Eastern Arabs of Saudi origin is still unclear. A recent genome-wide study identified two significant loci in the region of PNPLA2 (rs61876744) and CSNK1E (rs138380) for KC that may be associated with KC in the Saudi population. In addition, polymorphisms in the apolipoprotein E (APOE) gene, namely, rs429358 and rs7412, responsible for APOE allelic variants ε2, ε3, and ε4, may influence KC via oxidative stress mechanism(s). Thus, we investigated the possible association of polymorphisms rs61876744, rs138380, rs429358, rs7412, and APOE genotypes in KC patients of the Saudi population. This study included 98 KC cases and 167 controls. Polymorphisms rs6187644 and rs138380 were genotyped using TaqMan assays, and rs429358 and rs7412 were genotyped via Sanger sequencing. Although the allele frequency of rs61876744(T) in PNPLA2 was a protective effect against KC (odds ratio (OR) = 0.64, 95% confidence interval (CI) = 0.44-0.93), the p-value (p = 0.020) was not significant for multiple testing correction (p = 0.05/4 = 0.015). However, rs6187644 genotype showed a modestly significant protective effect in the dominant model (OR = 0.53, 95% CI = 0.32-0.88, p = 0.013). Polymorphisms rs138380, rs429358, and rs7412 showed no significant allelic or genotype association with KC. However, the ε2-carriers (ε2/ε2 and ε2/ε3 genotypes) exhibited a greater than 5-fold increased risk of KC, albeit non-significantly (p = 0.055). Regression analysis showed no significant effect of age, gender, and the four polymorphisms on KC. Our results suggest that polymorphism rs6187644 in PNPLA2 might be associated with KC in the Middle Eastern Arabs of Saudi origin but warrant a large-scale association analysis at this locus.
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Affiliation(s)
- Altaf A. Kondkar
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia; (T.A.A.); (T.S.); (H.K.); (S.A.A.-O.); (A.M.A.-M.)
- Glaucoma Research Chair in Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia
- King Saud University Medical City, King Saud University, Riyadh 11411, Saudi Arabia
| | - Taif A. Azad
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia; (T.A.A.); (T.S.); (H.K.); (S.A.A.-O.); (A.M.A.-M.)
| | - Tahira Sultan
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia; (T.A.A.); (T.S.); (H.K.); (S.A.A.-O.); (A.M.A.-M.)
| | - Tanvir Khatlani
- Department of Blood and Cancer Research, King Abdullah International Medical Research Center, King Saud Bin Abdulaziz University of Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia;
| | - Abdulaziz A. Alshehri
- Department of Ophthalmology, Imam Abdulrahman Alfaisal Hospital, Riyadh 14723, Saudi Arabia;
| | - Glenn P. Lobo
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55347, USA;
| | - Hatem Kalantan
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia; (T.A.A.); (T.S.); (H.K.); (S.A.A.-O.); (A.M.A.-M.)
| | - Saleh A. Al-Obeidan
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia; (T.A.A.); (T.S.); (H.K.); (S.A.A.-O.); (A.M.A.-M.)
- Glaucoma Research Chair in Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia
| | - Abdulrahman M. Al-Muammar
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh 11411, Saudi Arabia; (T.A.A.); (T.S.); (H.K.); (S.A.A.-O.); (A.M.A.-M.)
- King Saud University Medical City, King Saud University, Riyadh 11411, Saudi Arabia
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Abuallut II, Alomaish AR, Arishy AM, Mashragi MA, Alfaifi KH, Alnamazi NA, Moafa AM, Mahfouz MS, Moafa MA, Jafaari SA, Alagsam AA, Albalawi HB, Jareebi MA. A Cross-Sectional Analysis to Assess the Role of Atopy in Keratoconus Among Saudi Population. Int J Gen Med 2023; 16:4873-4881. [PMID: 37916193 PMCID: PMC10617398 DOI: 10.2147/ijgm.s421298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/26/2023] [Indexed: 11/03/2023] Open
Abstract
Background In cases of atopy, IgE antibodies are formed in reaction to certain environmental factors like house dust mites, pollen, or even food allergens. Some studies have shown an association between atopic diseases and keratoconus. This study aims to determine the prevalence of atopy and its associated factors among keratoconus patients. Materials and Methods A cross-sectional study was conducted among the Jazan population attending ophthalmology clinics regardless of their sex. Data collection started in August 2020 and finished in mid-June 2021. The sample was selected using the convenience sampling technique, and the total sample size was 83 participants. Data were collected via a questionnaire-based interview that contained 46 questions in the Arabic language. The data collected were analyzed using SPSS software. Results Family history is the leading predisposing factor for keratoconus (P < 0.001). Also, eye rubbing was a significant (P < 0.015) trigger for keratoconus. However, other factors, including demographic factors such as gender and atopic conditions, did not have any significant association. Conclusion A combination of genetic and environmental factors is the leading cause of the development of keratoconus; however, family history is the most influential factor, followed by eye rubbing.
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Affiliation(s)
- Ismail Ibrahim Abuallut
- Department of Surgery, Ophthalmology Division, Faculty of Medicine, Jazan University, Jazan, Saudi Arabia
| | | | | | | | | | | | | | - Mohamed S Mahfouz
- Department of Family and Community Medicine, Faculty of Medicine, Jazan University, Jazan, Saudi Arabia
| | - Majid A Moafa
- Optometric Department, Faculty of Medicine, Qassim University, Qassim, Saudi Arabia
| | - Sultan A Jafaari
- Department of Dermatology, King Fahd Central Hospital, Jazan, Saudi Arabia
| | - Abdulaziz A Alagsam
- Department of Ophthalmology, Mohammed Bin Nasser Hospital, Jazan, Saudi Arabia
| | - Hani Basher Albalawi
- Ophthalmology Division, Department of Surgery, Faculty of Medicine, University of Tabuk, Tabuk, Saudi Arabia
| | - Mohammad A Jareebi
- Department of Family and Community Medicine, Faculty of Medicine, Jazan University, Jazan, Saudi Arabia
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Sinjab MM. Keratoconus: A historical and prospective review. Oman J Ophthalmol 2023; 16:401-414. [PMID: 38059102 PMCID: PMC10697266 DOI: 10.4103/ojo.ojo_70_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 04/20/2023] [Accepted: 04/28/2023] [Indexed: 12/08/2023] Open
Abstract
This article is a historical and prospective review of keratoconus and ectatic corneal diseases. It covers definitions and terminology, the prevalence of keratoconus, predisposing factors, diagnosis, differential diagnosis, management, classifications, and progression criteria. It highlights other aspects of the disease that are usually over-missed, including the psychological, social, and economic impact. This review presents the information chronically in terms of the first author. It concludes by possessing the challenges and difficulties that are still to be overcome and suggests a plan.
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Affiliation(s)
- Mazen M. Sinjab
- Ophthalmology Department in Dr. Sulaiman Al Habib Hospital, DHCC, Dubai, UAE
- Sinjab Academy, International Keratoconus Society, Muscat, Oman
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5
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Sahebjada S, Chan E, Sutton G, Pang CPC, Kerdraon Y, Natarajan S, Meteoukki W, Ang A, Daniell M, Baird PN. Keratoconus International Consortium (KIC)- advancing keratoconus research. BMC Ophthalmol 2023; 23:337. [PMID: 37501133 PMCID: PMC10375634 DOI: 10.1186/s12886-023-03087-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 07/16/2023] [Indexed: 07/29/2023] Open
Abstract
CLINICAL RELEVANCE The Keratoconus International Consortium (KIC) will allow better understanding of keratoconus. BACKGROUND Keratoconus is a disorder characterised by corneal elevation and thinning, leading to reduced vision. The current gaps in understanding of this disease will be discussed and the need for a multi-pronged and multi-centre engagement to enhance our understanding of keratoconus will be highlighted. DESIGN KIC has been established to address the gaps in our understanding of keratoconus with the aim of collecting baseline as well as longitudinal data on several fields. PARTICIPANTS Keratoconus and control (no corneal condition) subjects from different sites globally will be recruited in the study. METHODS KIC collects data using an online, secure database, which enables standardised data collection at member sites. Data fields collected include medical history, clinical features, quality of life and economic burden questionnaires and possible genetic sample collection from patients of different ethnicities across different geographical locations. RESULTS There are currently 40 Australian and international clinics or hospital departments who have joined the KIC. Baseline data has so far been collected on 1130 keratoconus patients and indicates a median age of 29.70 years with 61% being male. A total of 15.3% report a positive family history of keratoconus and 57.7% self-report a history of frequent eye rubbing. CONCLUSION The strength of this consortium is its international, collaborative design and use of a common data collection tool. Inclusion and analyses of cross-sectional and longitudinal data will help answer many questions that remain in keratoconus, including factors affecting progression and treatment outcomes.
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Affiliation(s)
- Srujana Sahebjada
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia.
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia.
| | - Elsie Chan
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Gerard Sutton
- Sydney Medical School, The University of Sydney, Sydney, Australia
- NSW Tissue Banks, Sydney, Australia
| | | | - Yves Kerdraon
- Sydney Medical School, The University of Sydney, Sydney, Australia
- Envision Eye Centre, Sydney, Australia
| | | | - Wafaa Meteoukki
- Molecular and Cellular Genetics Laboratory, Oran University of Science and Technology - Mohamed Boudiaf (USTOMB), Oran, Algeria
| | | | - Mark Daniell
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Paul N Baird
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
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Peachey N, Gorman B, Francis M, Nealon C, Halladay C, Duro N, Markianos K, Genovese G, Hysi P, Choquet H, Afshari N, Li YJ, Gaziano JM, Hung A, Wu WC, Greenberg P, Pyarajan S, Lass J, Iyengar S. Multi-ancestry GWAS of Fuchs corneal dystrophy highlights roles of laminins, collagen, and endothelial cell regulation. RESEARCH SQUARE 2023:rs.3.rs-2762003. [PMID: 37205546 PMCID: PMC10187421 DOI: 10.21203/rs.3.rs-2762003/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a leading indication for corneal transplantation, but its molecular pathophysiology remains poorly understood. We performed genome-wide association studies (GWAS) of FECD in the Million Veteran Program (MVP) and meta-analyzed with the previous largest FECD GWAS, finding twelve significant loci (eight novel). We further confirmed the TCF4 locus in admixed African and Hispanic/Latino ancestries, and found an enrichment of European-ancestry haplotypes at TCF4 in FECD cases. Among the novel associations are low frequency missense variants in laminin genes LAMA5 and LAMB1 which, together with previously reported LAMC1, form laminin-511 (LM511). AlphaFold 2 protein modeling suggests that mutations at LAMA5 and LAMB1 may destabilize LM511 by altering inter-domain interactions or extracellular matrix binding. Finally, phenome-wide association scans and co-localization analyses suggest that the TCF4 CTG18.1 trinucleotide repeat expansion leads to dysregulation of ion transport in the corneal endothelium and has pleiotropic effects on renal function.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Hélène Choquet
- Division of Research, Kaiser Permanente Northern California
| | | | | | | | | | | | | | - Saiju Pyarajan
- Center for Data and Computational Sciences, Veterans Affairs Boston Healthcare System
| | - Jonathan Lass
- Case Western Reserve University and University Hospitals Case Medical Center
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Seth I, Bulloch G, Vine M, Outmezguine J, Seth N, Every J, Daniell M. The association between keratoconus and allergic eye diseases: A systematic review and meta-analysis. Clin Exp Ophthalmol 2023. [PMID: 36882200 DOI: 10.1111/ceo.14215] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 02/14/2023] [Indexed: 03/09/2023]
Abstract
BACKGROUND To investigate the association between keratoconus (KC) and allergic eye diseases, eye rubbing, and atopy. METHODS PubMed, Web of Science, Scopus, and Cochrane databases were searched for studies investigating eye allergy, atopy, and eye rubbing as risk factors for KC up to April 2021. Two authors independently screened all titles and abstracts against the predefined inclusion and exclusion criteria. The study analysed the prevalence of KC and its risk factors, including eye rubbing, family history of KC, atopy, and allergic eye diseases. The National Institutes of Health Study Quality Assessment Tool was used. Pooled data are presented as odds ratios (OR) and 95% confidence intervals (CI). The analysis was conducted using RevMan version 5.4 software. RESULTS The initial search yielded 573 articles. After screening, 21 studies were identified for qualitative analysis and 15 for quantitative synthesis. A significant association was found between KC and eye rubbing (OR = 5.22, 95% CI [2.80, 9.75], p < 0.00001), family history of KC (OR = 6.67, 95% CI [4.77, 9.33], p < 0.00001), and allergies (OR = 2.21, 95% CI [1.57, 3.13], p < 0.00001). However, no significant association was found between KC and allergic eye disease (OR = 1.82, 95% CI [0.37, 8.97], p = 0.46), atopy (OR = 1.54, 95% CI [0.58, 4.09], p = 0.39), allergic rhinitis (OR = 0.85, 95% CI [0.54, 1.33], p = 0.47), smoking (OR = 0.96, 95% CI [0.76, 1.21], p = 0.73), and asthma (OR = 1.58, 95% CI [0.99, 2.53], p = 0.05). CONCLUSION Significant associations were observed between KC and eye rubbing, family history, and allergy, but not with allergic eye disease, atopy, asthma, and allergic rhinitis.
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Affiliation(s)
- Ishith Seth
- Bendigo Base Hospital, Bendigo, Victoria, Australia.,Faculty of Science, Medicine and Health, University of Melbourne, Melbourne, Victoria, Australia.,Department of Ophthalmology, Centre for Eye Research Australia, East Melbourne, Victoria, Australia
| | - Gabriella Bulloch
- Faculty of Science, Medicine and Health, University of Melbourne, Melbourne, Victoria, Australia.,Department of Ophthalmology, Centre for Eye Research Australia, East Melbourne, Victoria, Australia
| | - Michael Vine
- Bendigo Base Hospital, Bendigo, Victoria, Australia
| | | | - Nimish Seth
- Department of Surgery, Alfred Health, Melbourne, Victoria, Australia
| | - James Every
- Bendigo Base Hospital, Bendigo, Victoria, Australia
| | - Mark Daniell
- Department of Ophthalmology, Centre for Eye Research Australia, East Melbourne, Victoria, Australia
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Ting DSJ, Deshmukh R, Ting DSW, Ang M. Big data in corneal diseases and cataract: Current applications and future directions. Front Big Data 2023; 6:1017420. [PMID: 36818823 PMCID: PMC9929069 DOI: 10.3389/fdata.2023.1017420] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/16/2023] [Indexed: 02/04/2023] Open
Abstract
The accelerated growth in electronic health records (EHR), Internet-of-Things, mHealth, telemedicine, and artificial intelligence (AI) in the recent years have significantly fuelled the interest and development in big data research. Big data refer to complex datasets that are characterized by the attributes of "5 Vs"-variety, volume, velocity, veracity, and value. Big data analytics research has so far benefitted many fields of medicine, including ophthalmology. The availability of these big data not only allow for comprehensive and timely examinations of the epidemiology, trends, characteristics, outcomes, and prognostic factors of many diseases, but also enable the development of highly accurate AI algorithms in diagnosing a wide range of medical diseases as well as discovering new patterns or associations of diseases that are previously unknown to clinicians and researchers. Within the field of ophthalmology, there is a rapidly expanding pool of large clinical registries, epidemiological studies, omics studies, and biobanks through which big data can be accessed. National corneal transplant registries, genome-wide association studies, national cataract databases, and large ophthalmology-related EHR-based registries (e.g., AAO IRIS Registry) are some of the key resources. In this review, we aim to provide a succinct overview of the availability and clinical applicability of big data in ophthalmology, particularly from the perspective of corneal diseases and cataract, the synergistic potential of big data, AI technologies, internet of things, mHealth, and wearable smart devices, and the potential barriers for realizing the clinical and research potential of big data in this field.
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Affiliation(s)
- Darren S. J. Ting
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom,Birmingham and Midland Eye Centre, Birmingham, United Kingdom,Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom,*Correspondence: Darren S. J. Ting ✉
| | - Rashmi Deshmukh
- Department of Cornea and Refractive Surgery, LV Prasad Eye Institute, Hyderabad, India
| | - Daniel S. W. Ting
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore (NUS) Medical School, Singapore, Singapore
| | - Marcus Ang
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore (NUS) Medical School, Singapore, Singapore
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Xu L, Yang K, Zhu M, Yin S, Gu Y, Fan Q, Wang Y, Pang C, Ren S. Trio-based exome sequencing broaden the genetic spectrum in keratoconus. Exp Eye Res 2023; 226:109342. [PMID: 36502923 DOI: 10.1016/j.exer.2022.109342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 11/09/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
Keratoconus (KC) is a complex corneal disorder with genetic factors involving in its pathogenesis. The genetic etiology of KC has not been fully elucidated. In this study, we aimed to expand the genetic spectrum in KC by trio-based exome sequencing. Trio-based exome sequencing was conducted in 20 patients with KC and their unaffected parents to broaden the genetic spectrum of the disease. With a series of filtering criteria, de novo, recessive homozygous, and compound heterozygous variants in candidate genes were identified, and the candidate genes were classified for further analysis. Finally, we identified 60 variants in 32 candidate genes through trio-based exome sequencing. Among the candidate genes, 10 genes (ARHGEF10, ARHGEF17, ASPM, FLNA, NDRG1, NEB, PLS3, STARD8, SYNE1, TTN) were classified as cytoskeleton-related genes, 4 genes (COL28A1, SDK1, STAB1, TENM2) were classified as cell adhesion-related genes, and 18 genes (APLP2, BCORL1, CCNB3, FOXN1, FUT8, GALNT10, HEPH, HHIP, HMGB3, HS6ST2, JADE3, KIAA0040, MCF2L, MYOF, QRICH2, RPS6KA6, SMARCA1, TNRC6A) were classified into other genes group. Additionally, the candidate rare deleterious variants in TTN were highly repeated in 25% trios. In conclusion, the study provided new insights into the genetic spectrum of KC which might underlie the genetic etiology for the disease. The findings would improve our understanding of pathogenesis in KC and provide critical clues to future functional validation.
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Affiliation(s)
- Liyan Xu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, 450003, China
| | - Kaili Yang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, 450003, China
| | - Meng Zhu
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institution, Zhengzhou, 450003, China
| | - Shanshan Yin
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institution, Zhengzhou, 450003, China
| | - Yuwei Gu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, 450003, China
| | - Qi Fan
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, 450003, China
| | - Yawen Wang
- Henan University People's Hospital, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, Zhengzhou, 450003, China
| | - Chenjiu Pang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, 450003, China
| | - Shengwei Ren
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, 450003, China; Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institution, Zhengzhou, 450003, China.
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Ouyang S, Ma J, Sun Q, Li J, Chen Y, Luo L. Comprehensive Bioinformatics Analysis to Reveal Key RNA Targets and Hub Competitive Endogenous RNA Network of Keratoconus. Front Genet 2022; 13:896780. [PMID: 35747602 PMCID: PMC9209702 DOI: 10.3389/fgene.2022.896780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/19/2022] [Indexed: 11/15/2022] Open
Abstract
Keratoconus (KC) is the most common corneal ectatic disease, with its pathological mechanisms unclear. We mainly performed bioinformatics approaches to reveal core RNA targets and hub competitive endogenous RNA (ceRNA) network and explored the potential regulatory mechanisms of ceRNA in KC. The high-throughput sequencing datasets GSE77938 and GSE151631 were downloaded from the Gene Expression Omnibus (GEO) database. The differential expression of mRNAs and lncRNAs was identified using the DESeq2 package. Functional enrichment analyses and protein–protein interaction (PPI) were executed. Then, the hub genes were filtered and molecular docking analysis was performed. Moreover, we predicted miRNAs through a website database and validated them using quantitative PCR (qPCR). Eventually, the lncRNA–miRNA–mRNA regulatory network was constructed by Cytoscape. We revealed that 428 intersected differentially expressed mRNA (DEGs) and 68 intersected differentially expressed lncRNA (DELs) were shared between the two datasets. Functional enrichment results innovatively showed that the ubiquitin-dependent protein catabolic process was upregulated in KC. The pathway enrichment showed that DEGs were mainly involved in NF-kB signaling and neurodegenerative diseases. In addition, we uncovered the top 20 hub genes in which FBXW11, FBXO9, RCHY1, and CD36 were validated by qPCR. Particularly, a small-molecule drug triptolide was predicted by molecular docking to be a candidate drug for treating KC. Moreover, we innovatively predicted and validated four core miRNAs (miR-4257, miR-4494, miR-4263, and miR-4298) and constructed a ceRNA network that contained 165 mRNA, eight lncRNAs, and four core miRNAs. Finally, we proposed a potential regulatory mechanism for KC. Overall, we uncovered a hub ceRNA network that might underlie a critical posttranslational regulatory mechanism in KC, in which miR-4257, miR-4494, miR-4263, and miR-4298 could be valuable biomarkers and provided core RNAs therapeutic targets for KC.
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11
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He W, Han X, Ong JS, Hewitt AW, Mackey DA, Gharahkhani P, MacGregor S. Association of Novel Loci With Keratoconus Susceptibility in a Multitrait Genome-Wide Association Study of the UK Biobank Database and Canadian Longitudinal Study on Aging. JAMA Ophthalmol 2022; 140:568-576. [PMID: 35446358 PMCID: PMC9026225 DOI: 10.1001/jamaophthalmol.2022.0891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Keratoconus can be a debilitating corneal ectasia in which the cornea thins, bulges, and steepens into a conical shape. Early features of keratoconus include myopia and irregular astigmatism, which affect vision and can be treated with contact lenses, collagen cross-linking, or, in advanced cases, corneal transplant. Recent estimates of the prevalence of keratoconus based on results of Scheimpflug imaging in young adults are as high as 1.2%. However, obtaining very large keratoconus data sets for a genome-wide association study (GWAS) is problematic because few population studies include Scheimpflug imaging and because severe keratoconus is relatively rare. Objective To identify novel keratoconus loci using corneal resistance factor (CRF) and central corneal thickness (CCT). Design, Setting, and Participants This multitrait GWAS used European ancestry CRF data from UK Biobank (UKB) (n = 105 427) and the Canadian Longitudinal Study on Aging (CLSA) (n = 18 307) and European ancestry CCT data from the International Glaucoma Genetics Consortium (IGGC) (n = 17 803). The CRF and CCT variants in published keratoconus data sets (4669 cases and 116 547 controls) were compared. The data set from UKB was compiled March 24, 2020; data were released from the CLSA in July 2020; and IGGC data were available from May 1, 2018. Main Outcomes and Measures Association of CRF and CCT variants with keratoconus risk. Results The GWAS included 4 cohorts: 105 427 UKB European ancestry (56 134 women [53.2%] and 49 293 men [46.7%]; mean [SD] age, 57 [8] years), 5029 UKB South Asian ancestry (2368 women [47.1%] and 2661 men [52.9%]; mean [SD] age, 54 [8] years), 902 UKB East Asian ancestry (622 women [68.9%] and 280 men [31.0%]; mean [SD] age, 53 [8] years), and 18 307 CLSA European ancestry (9260 women [50.6%] and 9047 men [49.4%]; mean [SD] age, 63 [10] years) participants. A total of 369 CRF and 233 CCT loci were identified, including 36 novel CRF loci and 114 novel CCT loci. Twenty-nine CRF loci and 24 CCT loci were associated with keratoconus. Polygenic risk scores (PRS) were constructed using CRF- and CCT-associated variants and published keratoconus variants. The PRS result showed that adding a CRF- or CCT-based PRS to the keratoconus PRS from previously published variants improved the prediction area under the receiver operating characteristic curve (from 0.705 to 0.756 for CRF and from 0.715 to 0.755 for CCT). Conclusions and Relevance These findings support the use of multitrait modeling of corneal parameters in a relatively large data set to identify new keratoconus risk loci and enhance polygenic risk score models.
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Affiliation(s)
- Weixiong He
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia
| | - Xikun Han
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia
| | - Jue-Sheng Ong
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Alex W Hewitt
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,School of Medicine, Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - David A Mackey
- Lions Eye Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
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12
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de Barros MRM, Chakravarti S. Pathogenesis of keratoconus: NRF2-antioxidant, extracellular matrix and cellular dysfunctions. Exp Eye Res 2022; 219:109062. [PMID: 35385756 DOI: 10.1016/j.exer.2022.109062] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/19/2022] [Accepted: 03/30/2022] [Indexed: 11/04/2022]
Abstract
Keratoconus (KC) is a degenerative disease associated with cell and extracellular matrix (ECM) loss that causes gradual thinning and steepening of the cornea and loss of vision. Collagen cross linking with ultraviolet light treatment can strengthen the ECM and delay weakening of the cornea, but severe cases require corneal transplantation. KC is multifactorial and multigenic, but its pathophysiology is still an enigma. Multiple approaches are being pursued to elucidate the molecular changes that underlie the corneal phenotype to identify relevant genes for tailored candidate searches and to develop potential biomarkers and targets for therapeutic interventions. Recent proteomic and transcriptomic studies suggest dysregulations in oxidative stress, NRF2-regulated antioxidant programs, WNT-signaling, TGF-β, ECM and matrix metalloproteinases. This review aims to provide a broad update on the transcriptomic and proteomic studies of KC with a focus on findings that relate to oxidative stress, and dysregulations in cellular and extracellular matrix functions.
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Affiliation(s)
| | - Shukti Chakravarti
- Department of Ophthalmology, NYU Grossman School of Medicine, NY, 10016, USA; Department of Pathology, NYU Grossman School of Medicine, NY, 10016, USA.
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13
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Yıldız E, Aydemir D, Zibandeh N, Kuşan E, Gümüş K, Saraç Öİ, Karslıoğlu MZ, Çağıl N, Şahin A. Investigation of Mitophagy Biomarkers in Corneal Epithelium of Keratoconus Patients. Curr Eye Res 2022; 47:661-669. [DOI: 10.1080/02713683.2022.2025846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Erdost Yıldız
- Koç University Research Center for Translational Medicine, Koç University, 34450, Istanbul, Turkey
| | - Dilara Aydemir
- Koç University Research Center for Translational Medicine, Koç University, 34450, Istanbul, Turkey
| | - Noushin Zibandeh
- Koç University Research Center for Translational Medicine, Koç University, 34450, Istanbul, Turkey
| | - Eda Kuşan
- Koç University Research Center for Translational Medicine, Koç University, 34450, Istanbul, Turkey
| | - Koray Gümüş
- Department of Ophthalmology, Ankara Memorial Hospital, 06520, Ankara, Turkey
| | - Özge İlhan Saraç
- Department of Ophthalmology, Ankara Yıldırım Beyazıt University, 06010, Ankara, Turkey
| | | | - Nurullah Çağıl
- Department of Ophthalmology, Ankara Yıldırım Beyazıt University, 06010, Ankara, Turkey
| | - Afsun Şahin
- Koç University Research Center for Translational Medicine, Koç University, 34450, Istanbul, Turkey
- Department of Ophthalmology, Koç University Medical School, 34010, Istanbul, Turkey
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14
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Novel Mutations Identified in the Chinese Han Population with Keratoconus by Next-Generation Sequencing. J Ophthalmol 2022; 2022:9991910. [PMID: 35186329 PMCID: PMC8853779 DOI: 10.1155/2022/9991910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 08/29/2021] [Accepted: 12/10/2021] [Indexed: 11/17/2022] Open
Abstract
Aim. To identify novel mutations in keratoconus (KC) susceptibility genes in the Chinese Han population. Methods. A total of fifty-two patients with primary KC were recruited. Blood samples were collected, and genomic DNA was isolated from peripheral blood leukocytes. The entire coding region, intron-exon junctions, and promoter regions of sixteen known KC susceptibility genes were screened with next-generation sequencing technology. All identified variants were further confirmed using the Sanger sequencing technology. The Sorting Intolerant from Tolerant (SIFT), MutationTaster, and PolyPhen 2 programs were used to predict the effect of amino acid substitution on protein. Results. After removing twelve known SNPs (single nucleotide polymorphisms) and three variants predicted to be harmless, nine novel mutations were identified in eight of the fifty-two patients, including c.455C > T:p.P152L in FNDC3B; c.3636_3637del:p.R1212fs in COL4A4; c.5015G > T:p.R1672L, c.3798dupA:p.P1267fs, and c.28G > A:p.A10T in MPDZ; c.1940C > T:p.P647L in DOCK9; c.127_128insGGC:p.Q43delinsRQ in POLG; c.3019G > A:p.V1007I in IPO5; and c.624 + 7− > A in TGFBI. All nine mutations in the patients with KC were heterozygote. Conclusion. This study enlarged the gene profile of KC and should be further confirmed by well-powered, genome-wide association studies (GWAS) of Han Chinese patients.
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15
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Hao XD, Gao H, Xu WH, Shan C, Liu Y, Zhou ZX, Wang K, Li PF. Systematically Displaying the Pathogenesis of Keratoconus via Multi-Level Related Gene Enrichment-Based Review. Front Med (Lausanne) 2022; 8:770138. [PMID: 35141241 PMCID: PMC8818795 DOI: 10.3389/fmed.2021.770138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/31/2021] [Indexed: 01/20/2023] Open
Abstract
Keratoconus (KC) is an etiologically heterogeneous corneal ectatic disorder. To systematically display the pathogenesis of keratoconus (KC), this study reviewed all the reported genes involved in KC, and performed an enrichment analysis of genes identified at the genome, transcription, and protein levels respectively. Combined analysis of multi-level results revealed their shared genes, gene ontology (GO), and pathway terms, to explore the possible pathogenesis of KC. After an initial search, 80 candidate genes, 2,933 transcriptional differential genes, and 947 differential proteins were collected. The candidate genes were significantly enriched in extracellular matrix (ECM) related terms, Wnt signaling pathway and cytokine activities. The enriched GO/pathway terms of transcription and protein levels highlight the importance of ECM, cell adhesion, and inflammatory once again. Combined analysis of multi-levels identified 13 genes, 43 GOs, and 12 pathways. The pathogenic relationships among these overlapping factors maybe as follows. The gene mutations/variants caused insufficient protein dosage or abnormal function, together with environmental stimulation, leading to the related functions and pathways changes in the corneal cells. These included response to the glucocorticoid and reactive oxygen species; regulation of various signaling (P13K-AKT, MAPK and NF-kappaB), apoptosis and aging; upregulation of cytokines and collagen-related enzymes; and downregulation of collagen and other ECM-related proteins. These undoubtedly lead to a reduction of extracellular components and induction of cell apoptosis, resulting in the loosening and thinning of corneal tissue structure. This study, in addition to providing information about the genes involved, also provides an integrated insight into the gene-based etiology and pathogenesis of KC.
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Affiliation(s)
- Xiao-Dan Hao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- *Correspondence: Xiao-Dan Hao
| | - Hua Gao
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China
- Shandong Eye Hospital, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Wen-Hua Xu
- Department of Inspection, The Medical Faculty of Qingdao University, Qingdao, China
| | - Chan Shan
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Ying Liu
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Zhi-Xia Zhou
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Kun Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- Kun Wang
| | - Pei-Feng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- Pei-Feng Li
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16
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Karamichos D, Escandon P, Vasini B, Nicholas SE, Van L, Dang DH, Cunningham RL, Riaz KM. Anterior pituitary, sex hormones, and keratoconus: Beyond traditional targets. Prog Retin Eye Res 2021; 88:101016. [PMID: 34740824 PMCID: PMC9058044 DOI: 10.1016/j.preteyeres.2021.101016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 12/13/2022]
Abstract
"The Diseases of the Horny-coat of The Eye", known today as keratoconus, is a progressive, multifactorial, non-inflammatory ectatic corneal disorder that is characterized by steepening (bulging) and thinning of the cornea, irregular astigmatism, myopia, and scarring that can cause devastating vision loss. The significant socioeconomic impact of the disease is immeasurable, as patients with keratoconus can have difficulties securing certain jobs or even joining the military. Despite the introduction of corneal crosslinking and improvements in scleral contact lens designs, corneal transplants remain the main surgical intervention for treating keratoconus refractory to medical therapy and visual rehabilitation. To-date, the etiology and pathogenesis of keratoconus remains unclear. Research studies have increased exponentially over the years, highlighting the clinical significance and international interest in this disease. Hormonal imbalances have been linked to keratoconus, both clinically and experimentally, with both sexes affected. However, it is unclear how (molecular/cellular signaling) or when (age/disease stage(s)) those hormones affect the keratoconic cornea. Previous studies have categorized the human cornea as an extragonadal tissue, showing modulation of the gonadotropins, specifically luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Studies herein provide new data (both in vitro and in vivo) to further delineate the role of hormones/gonadotropins in the keratoconus pathobiology, and propose the existence of a new axis named the Hypothalamic-Pituitary-Adrenal-Corneal (HPAC) axis.
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Affiliation(s)
- Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA.
| | - Paulina Escandon
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Brenda Vasini
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Sarah E Nicholas
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Lyly Van
- University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA; Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Deanna H Dang
- College of Medicine, University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Kamran M Riaz
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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17
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Skorodumova LO, Belodedova AV, Sharova EI, Zakharova ES, Iulmetova LN, Bikbov MM, Usubov EL, Antonova OP, Selezneva OV, Levchenko A, Fedorenko OY, Ivanova SA, Gainetdinov RR, Malyugin BE. Rare single nucleotide variants in COL5A1 promoter do not play a major role in keratoconus susceptibility associated with rs1536482. BMC Ophthalmol 2021; 21:357. [PMID: 34625056 PMCID: PMC8501560 DOI: 10.1186/s12886-021-02128-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 09/24/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Keratoconus is a chronic degenerative disorder of the cornea characterized by thinning and cone-shaped protrusions. Although genetic factors play a key role in keratoconus development, the etiology is still under investigation. The occurrence of single-nucleotide polymorphisms (SNPs) associated with keratoconus in Russian patients is poorly studied. The purpose of this study was to validate whether three reported keratoconus-associated SNPs (rs1536482 near the COL5A1 gene, rs2721051 near the FOXO1 gene, rs1324183 near the MPDZ gene) are also actual for a Russian cohort of patients. Additionally, we investigated the COL5A1 promoter sequence for single-nucleotide variants (SNVs) in a subgroup of keratoconus patients with at least one rs1536482 minor allele (rs1536482+) to assess the role of these SNVs in keratoconus susceptibility associated with rs1536482. METHODS This case-control study included 150 keratoconus patients and two control groups (main and additional, 205 and 474 participants, respectively). We performed PCR targeting regions flanking SNVs and the COL5A1 promoter, followed by Sanger sequencing of amplicons. The additional control group was genotyped using an SNP array. RESULTS The minor allele frequency was significantly different between the keratoconus and control cohorts (main and combined) for rs1536482, rs2721051, and rs1324183 (p-value < 0.05). The rare variants rs1043208782 and rs569248712 were found in the COL5A1 promoter in two out of 94 rs1536482+ keratoconus patients. CONCLUSION rs1536482, rs2721051, and rs1324183 were associated with keratoconus in a Russian cohort. SNVs in the COL5A1 promoter do not play a major role in keratoconus susceptibility associated with rs1536482.
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Affiliation(s)
- Liubov O Skorodumova
- Laboratory of Human Molecular Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Ul, Moscow, Russian Federation, 119435.
| | - Alexandra V Belodedova
- Laboratory of Human Molecular Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Ul, Moscow, Russian Federation, 119435.,Department of Anterior Segment Transplant and Optical Reconstructive Surgery, S. Fyodorov Eye Microsurgery Complex Federal State Institution, 59a Beskudnikovskiy Blv, Moscow, Russian Federation, 127486
| | - Elena I Sharova
- Laboratory of Human Molecular Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Ul, Moscow, Russian Federation, 119435
| | - Elena S Zakharova
- Laboratory of Human Molecular Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Ul, Moscow, Russian Federation, 119435
| | - Liliia N Iulmetova
- Laboratory of Human Molecular Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Ul, Moscow, Russian Federation, 119435
| | - Mukharram M Bikbov
- Department of Surgery of the Cornea and Lens, Ufa Eye Research Institute, Academy of Sciences of the Republic of Bashkortostan, 90 Pushkina Ul, Ufa, Russian Federation, 450008
| | - Emin L Usubov
- Department of Surgery of the Cornea and Lens, Ufa Eye Research Institute, Academy of Sciences of the Republic of Bashkortostan, 90 Pushkina Ul, Ufa, Russian Federation, 450008
| | - Olga P Antonova
- Department of Anterior Segment Transplant and Optical Reconstructive Surgery, S. Fyodorov Eye Microsurgery Complex Federal State Institution, 59a Beskudnikovskiy Blv, Moscow, Russian Federation, 127486
| | - Oksana V Selezneva
- Laboratory for Genomic Research and Computational Biology, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Ul, Moscow, Russian Federation, 119435
| | - Anastasia Levchenko
- Theodosius Dobzhansky Center for Genome Bioinformatics, Saint Petersburg State University, 7/9 Universitetskaya Nab, Saint Petersburg, 199034, Russia
| | - Olga Yu Fedorenko
- Laboratory of Molecular Genetics and Biochemistry, Mental Health Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, 4 Aleutskaya Ul, Tomsk, 634014, Russia.,Division for Testing and Diagnostics, National Research Tomsk Polytechnic University, 30 Lenina Prosp, Tomsk, 634050, Russia
| | - Svetlana A Ivanova
- Laboratory of Molecular Genetics and Biochemistry, Mental Health Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, 4 Aleutskaya Ul, Tomsk, 634014, Russia.,Division for Testing and Diagnostics, National Research Tomsk Polytechnic University, 30 Lenina Prosp, Tomsk, 634050, Russia.,Addiction Psychiatry and Psychotherapy Department, Siberian State Medical University, 2 Moskovsky Trakt, Tomsk, 634055, Russia
| | - Raul R Gainetdinov
- Laboratory of Neuroscience and Molecular Pharmacology, Institute of Translational Biomedicine and Saint Petersburg State University Hospital, Saint Petersburg State University, 7/9 Universitetskaya Nab, Saint Petersburg, 199034, Russia
| | - Boris E Malyugin
- Department of Anterior Segment Transplant and Optical Reconstructive Surgery, S. Fyodorov Eye Microsurgery Complex Federal State Institution, 59a Beskudnikovskiy Blv, Moscow, Russian Federation, 127486
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Abstract
Purpose of Review To summarize the recent advances in transcriptomics and proteomics studies of keratoconus using advanced genome-wide gene and protein expression profiling techniques. Recent Findings Second-generation sequencing including RNA sequencing has been widely used to characterize the genome-wide gene expression in corneal tissues or cells affected by keratoconus. Due to different sample types, sequencing platforms, and analysis pipeline, different lists of genes have been identified to be differentially expressed in KC-affected samples. Gene ontology and pathway/network analyses have indicated the involvement of genes related with extracellular matrix, WNT-signaling, TGFβ pathway, and NRF2-regulated network. High throughput proteomics studies using mass spectrometry have uncovered many KC-related protein molecules in pathways related with cytoskeleton, cell matrix, TGFβ signaling, and extracellular matrix remodeling, consistent with gene expression profiling. Summary Both transcriptomics and proteomics studies using genome-wide gene/protein expression profiling techniques have identified significant genes/proteins that may contribute to the pathogenesis of keratoconus. These molecules may be involved in functional categories related with extracellular matrix and TGFβ signaling. It is necessary to perform comprehensive gene/protein expression studies using larger sample size, same type of samples, up-to-date platform and bioinformatics tools.
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Resequencing of candidate genes for Keratoconus reveals a role for Ehlers-Danlos Syndrome genes. Eur J Hum Genet 2021; 29:1745-1755. [PMID: 33737726 DOI: 10.1038/s41431-021-00849-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/22/2021] [Accepted: 02/26/2021] [Indexed: 02/06/2023] Open
Abstract
The involvement of genetic factors in the pathogenesis of KC has long been recognized but the identification of variants affecting the underlying protein functions has been challenging. In this study, we selected 34 candidate genes for KC based on previous whole-exome sequencing (WES) and the literature, and resequenced them in 745 KC patients and 810 ethnically matched controls from Belgium, France and Italy. Data analysis was performed using the single variant association test as well as gene-based mutation burden and variance components tests. In our study, we detected enrichment of genetic variation across multiple gene-based tests for the genes COL2A1, COL5A1, TNXB, and ZNF469. The top hit in the single variant association test was obtained for a common variant in the COL12A1 gene. These associations were consistently found across independent subpopulations. Interestingly, COL5A1, TNXB, ZNF469 and COL12A1 are all known Ehlers-Danlos Syndrome (EDS) genes. Though the co-occurrence of KC and EDS has been reported previously, this study is the first to demonstrate a consistent role of genetic variants in EDS genes in the etiology of KC. In conclusion, our data show a shared genetic etiology between KC and EDS, and clearly confirm the currently disputed role of ZNF469 in disease susceptibility for KC.
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20
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Hardcastle AJ, Liskova P, Bykhovskaya Y, McComish BJ, Davidson AE, Inglehearn CF, Li X, Choquet H, Habeeb M, Lucas SEM, Sahebjada S, Pontikos N, Lopez KER, Khawaja AP, Ali M, Dudakova L, Skalicka P, Van Dooren BTH, Geerards AJM, Haudum CW, Faro VL, Tenen A, Simcoe MJ, Patasova K, Yarrand D, Yin J, Siddiqui S, Rice A, Farraj LA, Chen YDI, Rahi JS, Krauss RM, Theusch E, Charlesworth JC, Szczotka-Flynn L, Toomes C, Meester-Smoor MA, Richardson AJ, Mitchell PA, Taylor KD, Melles RB, Aldave AJ, Mills RA, Cao K, Chan E, Daniell MD, Wang JJ, Rotter JI, Hewitt AW, MacGregor S, Klaver CCW, Ramdas WD, Craig JE, Iyengar SK, O'Brart D, Jorgenson E, Baird PN, Rabinowitz YS, Burdon KP, Hammond CJ, Tuft SJ, Hysi PG. A multi-ethnic genome-wide association study implicates collagen matrix integrity and cell differentiation pathways in keratoconus. Commun Biol 2021; 4:266. [PMID: 33649486 PMCID: PMC7921564 DOI: 10.1038/s42003-021-01784-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 02/02/2021] [Indexed: 12/14/2022] Open
Abstract
Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease.
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Affiliation(s)
- Alison J Hardcastle
- UCL Institute of Ophthalmology, London, UK.
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK.
| | - Petra Liskova
- UCL Institute of Ophthalmology, London, UK
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Yelena Bykhovskaya
- The Cornea Eye Institute, Beverly Hills, CA, USA
- Department of Surgery and Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Bennet J McComish
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | | | - Chris F Inglehearn
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Xiaohui Li
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Hélène Choquet
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Mahmoud Habeeb
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Sionne E M Lucas
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Srujana Sahebjada
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | | | | | - Anthony P Khawaja
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK
- NIHR Biomedical Research Centre, Moorfields Eye Hospital, London, UK
| | - Manir Ali
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Pavlina Skalicka
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Bart T H Van Dooren
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Amphia Hospital, Breda, The Netherlands
| | | | - Christoph W Haudum
- Division of Endocrinology and Diabetology, Endocrinology Lab Platform, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Valeria Lo Faro
- Department of Ophthalmology, University Medical Center Groningen (UMCG), Groningen, the Netherlands
- Department of Ophthalmology, Academic Medical Center, Amsterdam, The Netherlands
| | - Abi Tenen
- Vision Eye Institute, Melbourne, VIC, Australia
- School of Primary and Allied Health Care, Monash University, Melbourne, VIC, Australia
- Melbourne Stem Cell Centre, Melbourne, VIC, 3800, Australia
| | - Mark J Simcoe
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Karina Patasova
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Darioush Yarrand
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Jie Yin
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Salina Siddiqui
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
- Department of Ophthalmology, St James's University Hospital, Leeds, UK
| | - Aine Rice
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Layal Abi Farraj
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Yii-Der Ida Chen
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Jugnoo S Rahi
- UCL Great Ormond Street Hospital Institute of Child Health, London, UK
| | | | | | - Jac C Charlesworth
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | | | - Carmel Toomes
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Magda A Meester-Smoor
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Andrea J Richardson
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Paul A Mitchell
- Centre for Vision Research, Department of Ophthalmology, Westmead Institute for Medical Research, University of Sydney, Westmead, NSW, Australia
| | - Kent D Taylor
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Ronald B Melles
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Anthony J Aldave
- The Jules Stein Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Richard A Mills
- Department of Ophthalmology, Flinders University, Adelaide, SA, Australia
| | - Ke Cao
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Elsie Chan
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Mark D Daniell
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Jie Jin Wang
- Health Services and Systems Research, Duke-NUS Medical School, Singapore, Singapore
| | - Jerome I Rotter
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Vision Eye Institute, Melbourne, VIC, Australia
- School of Primary and Allied Health Care, Monash University, Melbourne, VIC, Australia
- Melbourne Stem Cell Centre, Melbourne, VIC, 3800, Australia
| | - Stuart MacGregor
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Caroline C W Klaver
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Wishal D Ramdas
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Jamie E Craig
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Department of Ophthalmology, Flinders University, Adelaide, SA, Australia
| | - Sudha K Iyengar
- Department of Ophthalmology, Case Western Reserve University, Cleveland, OH, USA
| | - David O'Brart
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- St Thomas Hospital, Guy's and St. Thomas NHS Trust, London, London, UK
| | - Eric Jorgenson
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Paul N Baird
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Yaron S Rabinowitz
- The Cornea Eye Institute, Beverly Hills, CA, USA
- Department of Surgery and Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Kathryn P Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Department of Ophthalmology, Flinders University, Adelaide, SA, Australia
| | - Chris J Hammond
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
- St Thomas Hospital, Guy's and St. Thomas NHS Trust, London, London, UK
| | - Stephen J Tuft
- UCL Institute of Ophthalmology, London, UK.
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK.
| | - Pirro G Hysi
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK.
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
- UCL Great Ormond Street Hospital Institute of Child Health, London, UK.
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21
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Veerappa AM. Cascade of interactions between candidate genes reveals convergent mechanisms in keratoconus disease pathogenesis. Ophthalmic Genet 2021; 42:114-131. [PMID: 33554698 DOI: 10.1080/13816810.2020.1868013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Keratoconus is a progressive thinning, steepening and distortion of the cornea which can lead to loss of vision if left untreated. Keratoconus has a complex multifactorial etiology, with genetic and environmental components contributing to the disease pathophysiology. Studies have observed high concordance between monozygotic twins, discordance between dizygotic twins, and high familial segregation indicating the presence of a very strong genetic component in the pathogenesis of keratoconus. The use of genome-wide linkage studies on families and twins, genome-wide association studies (GWAS) on case-controls, next-generation sequencing (NGS)-based genomic screens on both familial and non-familial cohorts have led to the identification of keratoconus candidate genes with much greater success and increased resproducibility of genetic findings. This review focuses on candidate genes identified till date and attempts to understand their role in biological processes underlying keratoconus pathogenesis. In addition, using these genes I propose molecular pathways that could contribute to keratoconus pathogenesis. The pathways identified the presence of direct cross-talk between known candidate genes of keratoconus and remarkably, 28 known candidate genes have a direct relationship among themselves that involves direct protein-protein binding, regulatory activities such as activation and inhibition, chaperone, transcriptional activation/co-activation, and enzyme catalysis. This review attempts to describe these relationships and cross-talks in the context of keratoconus pathogenesis.
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Affiliation(s)
- Avinash M Veerappa
- Department of Ophthalmology, NYU Langone Medical Center, New York, New York, USA
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22
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Sahebjada S, Al-Mahrouqi HH, Moshegov S, Panchatcharam SM, Chan E, Daniell M, Baird PN. Eye rubbing in the aetiology of keratoconus: a systematic review and meta-analysis. Graefes Arch Clin Exp Ophthalmol 2021; 259:2057-2067. [PMID: 33484296 DOI: 10.1007/s00417-021-05081-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/03/2021] [Accepted: 01/09/2021] [Indexed: 12/14/2022] Open
Abstract
PURPOSE Keratoconus is a potentially blinding condition that slowly deforms the cornea in young people. Despite the increasing prevalence of keratoconus, the exact aetiology of the condition is unknown. This first systematic review examines the evidence of eye rubbing and its association with keratoconus and presents the findings of the meta-analysis. METHODS Two independent reviewers searched the electronic databases for all potential articles published from 1st of January 1900 to 31st of July 2020 on eye rubbing and keratoconus. The researchers assessed the methodological quality of the studies using the Newcastle-Ottawa scale for observational studies. The assessment for statistical heterogeneity was estimated using chi-square and I-square (I2) tests. A p value of < 0.05 was considered as statistically significant and I2 < 30% as homogenous. Begg funnel plot was used to interpret the asymmetry or small study effects. RESULTS Eight case-control studies were included in this systematic review. Two studies assessed eye rubbing without odds ratios and thus were excluded. The pooled odds ratios for the six remaining studies included in the meta-analysis was 6.46 (95% CI 4.12-10.1). The study results were heterogenous (I2 = 71.69 [95% CI 35.14-87.88]). All the studies scored moderate quality methodology on the Newcastle-Ottawa scale. Begg funnel plot showed asymmetry supporting heterogeneity. CONCLUSION Eye rubbing showed consistent association with keratoconus. However, the current evidence is limited to only a small number of case-control studies which present as heterogeneous and of sub-optimal methodological quality. Additionally, the cause-effect temporal relationship cannot be determined. Further studies are needed to address this intricate relationship of eye rubbing and its induction, ongoing progression, and severity of keratoconus.
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Affiliation(s)
- Srujana Sahebjada
- Department of Surgery, Ophthalmology, The University of Melbourne, Level 7, 32 Gisborne St, East Melbourne, VIC, 3002, Australia.
- Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Level 7, 32 Gisborne St, East Melbourne, VIC, 3002, Australia.
- Centre for Eye Research Australia, Melbourne, Australia.
| | | | - Sophia Moshegov
- Department of Surgery, Ophthalmology, The University of Melbourne, Level 7, 32 Gisborne St, East Melbourne, VIC, 3002, Australia
- Centre for Eye Research Australia, Melbourne, Australia
| | | | - Elsie Chan
- Department of Surgery, Ophthalmology, The University of Melbourne, Level 7, 32 Gisborne St, East Melbourne, VIC, 3002, Australia
- Centre for Eye Research Australia, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Mark Daniell
- Department of Surgery, Ophthalmology, The University of Melbourne, Level 7, 32 Gisborne St, East Melbourne, VIC, 3002, Australia
- Centre for Eye Research Australia, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Paul N Baird
- Department of Surgery, Ophthalmology, The University of Melbourne, Level 7, 32 Gisborne St, East Melbourne, VIC, 3002, Australia
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23
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Bykhovskaya Y, Rabinowitz YS. Update on the genetics of keratoconus. Exp Eye Res 2020; 202:108398. [PMID: 33316263 DOI: 10.1016/j.exer.2020.108398] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 02/07/2023]
Abstract
In the past few years we have seen a great acceleration of discoveries in the field of keratoconus including new treatments, diagnostic tools, genomic and molecular determinants of disease risk. Recent genome-wide association studies (GWAS) of keratoconus cases and population wide studies of variation in central corneal thickness and in corneal biomechanical properties confirmed already identified genes and found many new susceptibility variants and biological pathways. Recent findings in genetic determinants of familial keratoconus revealed functionally important variants and established first mouse model of keratoconus. Latest transcriptomic and expression studies started assessing novel non-coding RNA targets in addition to identifying tissue specific effects of coding genes. First genomic insights into better prediction of treatment outcomes are bringing the advent of genomic medicine into keratoconus clinical practice.
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Affiliation(s)
- Yelena Bykhovskaya
- Cornea Genetic Eye Institute, Department of Surgery and Board of the Governors Regenerative Medicine Institute, Beverly Hills, Cedars-Sinai, Los Angeles, CA, United States.
| | - Yaron S Rabinowitz
- Cornea Genetic Eye Institute, Department of Surgery and Board of the Governors Regenerative Medicine Institute, Beverly Hills, Cedars-Sinai, Los Angeles, CA, United States
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24
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Crawford AZ, Zhang J, Gokul A, McGhee CNJ, Ormonde SE. The Enigma of Environmental Factors in Keratoconus. Asia Pac J Ophthalmol (Phila) 2020; 9:549-556. [PMID: 33284230 DOI: 10.1097/apo.0000000000000334] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Keratoconus is an ectatic disorder with highly complex and varied causes including genetic variations and environmental factors. Its prevalence varies widely between regions and countries. Many environmental factors have been proposed to be associated with keratoconus, but the interpretation of their individual contributions is difficult due to the presence of many confounding variables. The current literature was reviewed to evaluate the strength of the associations and the causative effects of environmental factors on keratoconus. Ethnicity and consanguinity have been revealed as important determinants for geographical variations in keratoconus prevalence. Eye rubbing, atopy, floppy eyelid syndrome, contact lens wear, pregnancy, and thyroid hormone disturbances are likely associated with keratoconus. The first 4 factors can induce ocular surface inflammation, matrix metalloproteinase release, and keratocyte apoptosis, consistent with the postulated etiology of keratoconus. The associations of keratoconus with UV exposure, cigarette smoking, personality, and sex were less convincing once confounding factors were considered. Future studies powered for multivariate analysis of factors discussed will hopefully shed light on what is truly important in the development and progression of keratoconus.
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Affiliation(s)
- Alexandra Z Crawford
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Department of Ophthalmology, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand
| | - Jie Zhang
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Akilesh Gokul
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Charles N J McGhee
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Department of Ophthalmology, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand
| | - Sue E Ormonde
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Department of Ophthalmology, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand
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25
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Abstract
Ectatic corneal disease (ECD) comprises a group of disorders characterized by progressive thinning and subsequent bulging of the corneal structure. Different phenotypes have been recognized, including keratoglobus, pellucid marginal degeneration (PMD), and keratoconus (KC). Keratoconus has been widely investigated throughout the years, but the advent of laser refractive surgery boosted an immediate need for more knowledge and research about ectatic diseases. This article discusses nomenclature of ectatic disease, etiology and pathogenesis, along with treatment options, with special focus ok KC and forme fruste keratoconus.
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26
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Genetics vs chronic corneal mechanical trauma in the etiology of keratoconus. Exp Eye Res 2020; 202:108328. [PMID: 33172608 DOI: 10.1016/j.exer.2020.108328] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/17/2020] [Accepted: 10/20/2020] [Indexed: 12/20/2022]
Abstract
Both genetic and environmental factors have been considered to play a role in the etiology keratoconus. Eye rubbing, and more recently eye compression due to sleeping position, have been identified to be highly related to the condition, and are present in a high percentage of patients. Today, the predominant model is that these factors can provide the "second hit" necessary to generate the condition in a genetically susceptible individual. In addition, the extremely high prevalence in Arab populations, where endogamy could play a role, the high concordance rate in monozygotic twins, and the presence of family history of the condition between 5 and 23% of cases, support a genetic influence. Segregation analysis studies suggest that keratoconus is a complex non-Mendelian disease. Results from linkage analysis, next generation sequencing studies and genome-wide association studies also have suggested that genetic factors are involved in the condition. Recently, it has been proposed that mechanical trauma (i.e. eye rubbing or eye compression at night), is a sine quanon condition for the onset of keratoconus, and quite possibly its only cause. There are various arguments for and against this hypothesis. Indeed, it is possible, as initially suggested around 55 years ago, that the term "keratoconus" include diverse phenotypically similar conditions, which are actually of different etiology.
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27
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Short-term bilateral keratoconus progression after deep anterior lamellar keratoplasty in one eye and intracorneal ring segments and corneal crosslinking in the other due to eye rubbing. J Cataract Refract Surg 2020; 46:e44-e47. [PMID: 32925655 DOI: 10.1097/j.jcrs.0000000000000422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A 15-year-old boy had deep anterior lamellar keratoplasty in the right eye and intracorneal ring segments/corneal crosslinking in the left eye for the treatment of progressive keratoconus due to eye rubbing. He achieved a good surgical results, and 6 months later, the uncorrected distance visual acuity (UDVA) was 0.30 logarithm of the minimum angle of resolution (logMAR) in each eye, the refraction in the right eye was plano -2.75 × 135 = 0.30 logMAR and in the left eye was -0.75 -2.50 × 45 = 0.18 logMAR. Twelve months postoperatively, there was recurrence of intense eye rubbing. UDVA dropped, and bilateral corneal steepening was noted. Bilateral corneal crosslinking was performed along with an allergist consultation for eye rubbing control. Ten years later, his UDVA was 1.3 logMAR and 0.40 logMAR and corrected distance visual acuity was 0.10 logMAR and 0.18 logMAR in the right and left eyes, respectively.
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28
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Zhang J, Li Y, Dai Y, Xu J. Replication of the Association Between Keratoconus and Polymorphisms in PNPLA2 and MAML2 in a Han Chinese Population. Front Genet 2020; 11:827. [PMID: 32793291 PMCID: PMC7387689 DOI: 10.3389/fgene.2020.00827] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/09/2020] [Indexed: 12/11/2022] Open
Abstract
Keratoconus (KC) is a complex ocular disease that is affected by both genetic and non-genetic triggers. A recent genome-wide association study (GWAS) identified a genome-wide significant locus for KC in the region of PNPLA2 (rs61876744), as well as a suggestive signal in the MAML2 (rs10831500) locus. In order to validate their findings, here we performed a replication study of the Han Chinese population, with 120 sporadic KC cases and 206 gender and age matched control subjects, utilizing the TaqMan SNP genotyping assays. SNP rs10831500, as well as two proxy SNPs for rs61876744, named rs7942159 and rs28633403, were subjected to genotyping. However, we did not find a significant difference (P > 0.05) in all the three genotyped SNPs between KC cases and the controls. A further meta-analysis on four previous cohorts of white patients and this Han Chinese cohort showed a significant genetic heterogeneity within the replicated loci. Thus, the current study suggests that SNP rs61876744 (or its proxy SNPs) and rs10831500 might not be associated with KC susceptibility in this Han Chinese cohort, and a large-scale association analysis focusing on the loci is therefore warranted in further investigations.
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Affiliation(s)
- Jing Zhang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Yue Li
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Yiqin Dai
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Jianjiang Xu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
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29
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Abstract
Keratoconus, a progressive corneal ectasia, is a complex disease with both genetic and environmental risk factors. The exact etiology is not known and is likely variable between individuals. Conditions such as hay fever and allergy are associated with increased risk, while diabetes may be protective. Behaviors such as eye rubbing are also implicated, but direct causality has not been proven. Genetics plays a major role in risk for some individuals, with many large pedigrees showing autosomal inheritance patterns. Several genes have been implicated using linkage and follow-up sequencing in these families. Genome-wide association studies for keratoconus and for quantitative traits such as central corneal thickness have identified several genetic loci that contribute to a cumulative risk for keratoconus, even in people without a family history of the disease. Identification of risk genes for keratoconus is improving our understanding of the biology of this complex disease.
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Affiliation(s)
- Sionne E M Lucas
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7001, Australia;
| | - Kathryn P Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7001, Australia;
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