Genome-wide association studies (GWAS) have dissected numerous genetic factors underlying refractive errors (RE) such as myopia. Despite significant insights into understanding the genetic ...architecture of RE, few studies have validated and explored the functional role of candidate genes within these loci. To functionally follow-up on GWAS and characterize the potential role of candidate genes on the development of RE, we prioritized nine genes (TJP2, PDE11A, SHISA6, LAMA2, LRRC4C, KCNQ5, GNB3, RBFOX1, and GRIA4) based on biological and statistical evidence; and used CRISPR/cas9 to generate knock-out zebrafish mutants. These mutant fish were screened for abnormalities in axial length by spectral-domain optical coherence tomography and refractive status by eccentric photorefraction at the juvenile (2 months) and adult (4 months) developmental stage. We found a significantly increased axial length and myopic shift in refractive status in three of our studied mutants, indicating a potential involvement of the human orthologs (LAMA2, LRRC4C, and KCNQ5) in myopia development. Further, in-situ hybridization studies showed that all three genes are expressed throughout the zebrafish retina. Our zebrafish models provide evidence of a functional role of these three genes in refractive error development and offer opportunities to elucidate pathways driving the retina-to-sclera signaling cascade that leads to myopia.
To report long-term treatment outcomes of intravitreal bevacizumab in myopic macular neovascularization (MNV).
Retrospective analysis of longitudinal, clinical data of patients with high myopic MNV ...treated with intravitreal bevacizumab. One-hundred and seventeen eyes of 106 patients were followed from first injection up to 12 years. Outcome measures were best-corrected visual acuity change during follow-up and myopic MNV recurrence.
Mean (±SD) baseline best-corrected visual acuity (0.56 ± 0.46 logMAR, 20/80) significantly improved after first treatment (0.33 ± 0.33, 20/50, P < 0.001). At 4 years (n = 86), best-corrected visual acuity was no longer significantly better than at baseline (0.55 ± 0.57, P = 0.30) and continued to deteriorate to 0.84 ± 0.76 (20/125) at 10 years (n = 27). Of the 27 eyes (23%) who reached 10 years of follow-up, 53% developed MNV-related chorioretinal atrophy. The cumulative incidence of recurrent myopic MNV was 34% at 2 years and 59% at 5 years. Best-corrected visual acuity decrease in eyes with or without recurrent MNV was similar ( P = 0.58). Patchy chorioretinal atrophy (hazard ratio 3.0, P = 0.02) and subfoveal MNVs (hazard ratio 2.5, P = 0.048) were significantly associated with recurrent MNV.
This retrospective myopic MNV study revealed that visual improvement after intravitreal bevacizumab injections was not maintained over time. Macular neovascularization recurrences occurred frequently but did not alter the already poor visual prognosis.
Refractive errors, in particular myopia, are a leading cause of morbidity and disability worldwide. Genetic investigation can improve understanding of the molecular mechanisms that underlie abnormal ...eye development and impaired vision. We conducted a meta-analysis of genome-wide association studies (GWAS) that involved 542,934 European participants and identified 336 novel genetic loci associated with refractive error. Collectively, all associated genetic variants explain 18.4% of heritability and improve the accuracy of myopia prediction (area under the curve (AUC) = 0.75). Our results suggest that refractive error is genetically heterogeneous, driven by genes that participate in the development of every anatomical component of the eye. In addition, our analyses suggest that genetic factors controlling circadian rhythm and pigmentation are also involved in the development of myopia and refractive error. These results may enable the prediction of refractive error and the development of personalized myopia prevention strategies in the future.
Education influences the role of genetics in myopia VERHOEVEN, Virginie J. M; BUITENDIJK, Gabriëlle H. S; RIVADENEIRA, Fernando ...
European journal of epidemiology,
12/2013, Letnik:
28, Številka:
12
Journal Article
IMI - Myopia Control Reports Overview and Introduction Wolffsohn, James S; Flitcroft, Daniel Ian; Gifford, Kate L ...
Investigative ophthalmology & visual science,
2019-Feb-28, Letnik:
60, Številka:
3
Journal Article
Recenzirano
Odprti dostop
With the growing prevalence of myopia, already at epidemic levels in some countries, there is an urgent need for new management approaches. However, with the increasing number of research ...publications on the topic of myopia control, there is also a clear necessity for agreement and guidance on key issues, including on how myopia should be defined and how interventions, validated by well-conducted clinical trials, should be appropriately and ethically applied. The International Myopia Institute (IMI) reports the critical review and synthesis of the research evidence to date, from animal models, genetics, clinical studies, and randomized controlled trials, by more than 85 multidisciplinary experts in the field, as the basis for the recommendations contained therein. As background to the need for myopia control, the risk factors for myopia onset and progression are reviewed. The seven generated reports are summarized: (1) Defining and Classifying Myopia, (2) Experimental Models of Emmetropization and Myopia, (3) Myopia Genetics, (4) Interventions for Myopia Onset and Progression, (5) Clinical Myopia Control Trials and Instrumentation, (6) Industry Guidelines and Ethical Considerations for Myopia Control, and (7) Clinical Myopia Management Guidelines.
Primary open angle glaucoma (POAG) is a complex progressive optic nerve neuropathy triggered by both environmental and genetic risk factors. Several ocular tissues, including the ciliary body, ...trabecular meshwork and optic nerve head, and perhaps even brain tissues, are involved in a chain of pathological events leading to POAG.
Genetic risk evidence for POAG came from family linkage-studies implicating a small number of disease genes (MYOC, OPTN, WDR36). Recent Genome Wide Association Studies (GWAS) identified a large number of new POAG loci and disease genes, such as CAV1, CDKN2B and GAS7. In the current study, we reviewed over 120 family and GWA studies. We selected in total 65 (candidate) POAG disease genes and proceeded to assess their function, mRNA expression in POAG relevant eye tissues and possible changes in disease state. We found that the proteins corresponding to these 65 (candidate) POAG disease genes take part in as few as four common functional molecular networks. Functions attributed to these 4 networks were developmental (dys)function, lipid metabolism, and inflammatory processes. For the 65 POAG disease genes, we reviewed the available (transgenic) mouse models of POAG, which may be useful for future functional studies. Finally, we showed that the 65 (candidate) POAG genes substantially increased the specificity and sensitivity of a discriminative POAG risk test. This suggests that personal risk assessment and personalized medicine for POAG are on the horizon. Taken together, the data presented are essential to comprehend the role of genetic variation in POAG, and may provide leads to understand the pathophysiology of POAG as well as other neurodegenerative disorders, such as Alzheimer's disease.
•We reviewed the pathobiology of POAG.•We reviewed 70 genetic POAG loci and selected 65 candidate POAG disease genes.•Candidate POAG genes are often highly expressed in several POAG-involved tissue.•The 65 candidate POAG genes were functionally annotated in 4 molecular networks.•The 65 candidate POAG genes yield a very high discriminative risk testing ability.
Myopia is a refractive error of the eye caused by a complex interplay between nature and nurture. The aim of this study was to investigate whether environmental risk factors can influence the genetic ...effect in children developing myopia. A total of 3422 children participating in the birth-cohort study Generation R underwent an extensive eye examination at 9 years with measurements of refractive error and axial length corneal radius ratio (AL/CR). Environmental risk factors were evaluated using a questionnaire, and environmental risk scores (ERS) were calculated using backward regression analyses. Genetic risk scores (GRS) were calculated based on all currently known risk variants for myopia. Gene-environment interaction (G×E) was investigated using linear and logistic regression analyses. The predictive value of G×E and parental myopia was estimated using receiver operating characteristic curves. Myopia prevalence was 12%. Both GRS (P < 0.01) and ERS (P < 0.01) were significantly associated with myopia and AL/CR, as was G×E interaction (P < 0.01 for myopia; P = 0.07 for AL/CR). The predictive value of parental myopia was 0.67 (95% CI 0.65–0.70), similar to the values of GRS (0.67; 95% CI 0.64–0.70; P = 0.98) and ERS (0.69; 95% CI 0.66–0.72; P = 0.98). Adding G×E interaction significantly improved the predictive value to 0.73 (95% CI 0.70–0.75; P < 0.01). This study provides evidence that nature and nurture are equally important for myopia and AL/CR; however, the combination has the strongest influence. Since myopia genes are common in the population, adjustment of lifestyle should be a major focus in the prevention of myopia.
Cone photoreceptor disorders form a clinical spectrum of diseases that include progressive cone dystrophy (CD) and complete and incomplete achromatopsia (ACHM). The underlying disease mechanisms of ...autosomal recessive (ar)CD are largely unknown. Our aim was to identify causative genes for these disorders by genome-wide homozygosity mapping. We investigated 75 ACHM, 97 arCD, and 20 early-onset arCD probands and excluded the involvement of known genes for ACHM and arCD. Subsequently, we performed high-resolution SNP analysis and identified large homozygous regions spanning the PDE6C gene in one sibling pair with early-onset arCD and one sibling pair with incomplete ACHM. The PDE6C gene encodes the cone α subunit of cyclic guanosine monophosphate (cGMP) phosphodiesterase, which converts cGMP to 5′-GMP, and thereby plays an essential role in cone phototransduction. Sequence analysis of the coding region of PDE6C revealed homozygous missense mutations (p.R29W, p.Y323N) in both sibling pairs. Sequence analysis of 104 probands with arCD and 10 probands with ACHM revealed compound heterozygous PDE6C mutations in three complete ACHM patients from two families. One patient had a frameshift mutation and a splice defect; the other two had a splice defect and a missense variant (p.M455V). Cross-sectional retinal imaging via optical coherence tomography revealed a more pronounced absence of cone photoreceptors in patients with ACHM compared to patients with early-onset arCD. Our findings identify PDE6C as a gene for cone photoreceptor disorders and show that arCD and ACHM constitute genetically and clinically overlapping phenotypes.
The optic nerve head is involved in many ophthalmic disorders, including common diseases such as myopia and open-angle glaucoma. Two of the most important parameters are the size of the optic disc ...area and the vertical cup-disc ratio (VCDR). Both are highly heritable but genetically largely undetermined. We performed a meta-analysis of genome-wide association (GWA) data to identify genetic variants associated with optic disc area and VCDR. The gene discovery included 7,360 unrelated individuals from the population-based Rotterdam Study I and Rotterdam Study II cohorts. These cohorts revealed two genome-wide significant loci for optic disc area, rs1192415 on chromosome 1p22 (p = 6.72x10(-19)) within 117 kb of the CDC7 gene and rs1900004 on chromosome 10q21.3-q22.1 (p = 2.67x10(-33)) within 10 kb of the ATOH7 gene. They revealed two genome-wide significant loci for VCDR, rs1063192 on chromosome 9p21 (p = 6.15x10(-11)) in the CDKN2B gene and rs10483727 on chromosome 14q22.3-q23 (p = 2.93x10(-10)) within 40 kbp of the SIX1 gene. Findings were replicated in two independent Dutch cohorts (Rotterdam Study III and Erasmus Rucphen Family study; N = 3,612), and the TwinsUK cohort (N = 843). Meta-analysis with the replication cohorts confirmed the four loci and revealed a third locus at 16q12.1 associated with optic disc area, and four other loci at 11q13, 13q13, 17q23 (borderline significant), and 22q12.1 for VCDR. ATOH7 was also associated with VCDR independent of optic disc area. Three of the loci were marginally associated with open-angle glaucoma. The protein pathways in which the loci of optic disc area are involved overlap with those identified for VCDR, suggesting a common genetic origin.
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