90 research outputs found
Design of Smart Head-Mounted Display Technology: A convergent mixed methods study
The purpose of this study was to explore the factors impacting preference for head-mounted display (HMD) technology among individuals with visual impairment. HMD are commercially available assistive devices intended for those with low vision. Individuals with a range of visual impairment and diagnosis of either age-related macular degeneration, diabetic retinopathy, glaucoma or retinitis pigmentosa were recruited. Participants completed the Impact of Vision Impairment (IVI) questionnaire, were taught to use three different HMDs (eSight, Epson Moverio, and NuEyes) and were subsequently interviewed regarding their experience. Interviews were recorded, transcribed, and coded by two independent coders. Qualitative data was analyzed using a thematic approach and a joint display analysis was conducted. Twenty-one participants were interviewed (mean age 58.2 years, 57% male, median Snellen acuity 20/40 [range 20/20-hand movement]). An equal number of participants (n=9) expressed preference for eSight and NuEyes, while (n=3) preferred the Epson Moverio. Participants emphasized ease of use, especially of HMD controls and screen, as primary reasons for HMD preference. Participants with lower IVI Well-Being scores were more likely to express eSight preference due to clarity, ease of use, and vision improvement. Those with moderate IVI Well-Being scores were more likely to prefer the NuEyes due to appearance, wireless design, and magnification. Those with higher IVI Well-Being scores cited usability as the most important HMD feature. This study found that user preferences for HMD was associated with vision-related well-being, and that usability of devices was paramount in preference
Concordance of Aqueous Humor Flow in the Morning and at Night in Normal Humans
PURPOSE. To test the hypothesis that an individual shows concordance of aqueous humor flow in the morning and at night in a prospective inpatient fluorophotometry study in healthy subjects. METHODS. Flow was measured in each eye every hour between 8 AM and noon and every 2 hours between midnight and 6 AM. Morning and nighttime flows were analyzed for differences between eyes and for differences between these two time points. Concordance of individual morning and nighttime flows were studied by categorization into low, medium, or high tertiles, dot plot, and ordinary least-squares regression (OLS) scatter plot. RESULTS. In 28 subjects, the flow was similar between eyes within a subject with healthy eyes. In the one eye examined in each subject, the average flow was 3.12 Ϯ 1.09 L/min in the morning, which decreased significantly to 1.59 Ϯ 0.58 L/min at night. During each time period, the individual flow data were normally distributed. Concordance of an individual's morning and nighttime flows was 68%. A scatter plot of morning versus nighttime flows also supported concordance with an OLS regression fit of r 2 ϭ 0.45. CONCLUSIONS. The results provide evidence that aqueous humor flow is similar between eyes, that flow variation shows a normal distribution, and that individuals show a concordance of flow in the morning and at night. These observations support the posit that aqueous humor flow, which is a factor that contributes to the important clinical risk factor of IOP variation, is amenable to study as a quantitative trait. (Invest Ophthalmol Vis Sci. 2006;47: 4860 -4864
GALC Deletions Increase the Risk of Primary Open-Angle Glaucoma: The Role of Mendelian Variants in Complex Disease
DNA copy number variants (CNVs) have been reported in many human diseases including autism and schizophrenia. Primary Open Angle Glaucoma (POAG) is a complex adult-onset disorder characterized by progressive optic neuropathy and vision loss. Previous studies have identified rare CNVs in POAG; however, their low frequencies prevented formal association testing. We present here the association between POAG risk and a heterozygous deletion in the galactosylceramidase gene (GALC). This CNV was initially identified in a dataset containing 71 Caucasian POAG cases and 478 ethnically matched controls obtained from dbGAP (study accession phs000126.v1.p1.) (p = 0.017, fisher's exact test). It was validated with array comparative genomic hybridization (arrayCGH) and realtime PCR, and replicated in an independent POAG dataset containing 959 cases and 1852 controls (p = 0.021, OR (odds ratio) = 3.5, 95% CI −1.1–12.0). Evidence for association was strengthened when the discovery and replication datasets were combined (p = 0.002; OR = 5.0, 95% CI 1.6–16.4). Several deletions with different endpoints were identified by array CGH of POAG patients. Homozygous deletions that eliminate GALC enzymatic activity cause Krabbe disease, a recessive Mendelian disorder of childhood displaying bilateral optic neuropathy and vision loss. Our findings suggest that heterozygous deletions that reduce GALC activity are a novel mechanism increasing risk of POAG. This is the first report of a statistically-significant association of a CNV with POAG risk, contributing to a growing body of evidence that CNVs play an important role in complex, inherited disorders. Our findings suggest an attractive biomarker and potential therapeutic target for patients with this form of POAG
Variation in optineurin (OPTN) allele frequencies between and within populations
PURPOSE: To evaluate the extent to which mutations in the optineurin (OPTN) glaucoma gene play a role in glaucoma in
different populations.
METHODS: Case-controlled study of OPTN sequence variants in individuals with or without glaucoma in populations of
different ancestral origins and evaluate previous OPTN reports. We analyzed 314 subjects with African, Asian, Caucasian
and Hispanic ancestries included 229 cases of primary open-angle glaucoma, 51 cases of juvenile-onset open-angle glaucoma,
33 cases of normal tension glaucoma, and 371 controls. Polymerase chain reaction-amplified OPTN coding exons
were resequenced and case frequencies were compared to frequencies in controls matched for ancestry.
RESULTS: The E50K sequence variant was identified in one individual from Chile with normal tension glaucoma, and the
691_692insAG variant was found in one Ashkenazi Jewish individual from Russia. The R545Q variant was found in two
Asian individuals with primary open-angle glaucoma; one of Filipino ancestry and one of Korean ancestry. In addition to
presenting OPTN allele frequencies for Caucasian and Asian populations that have been the subject of previous reports,
we also present information for populations of Hispanic and black African ancestries.
CONCLUSIONS: Our study contributes additional evidence to support the previously reported association of the OPTN E50K
mutation with glaucoma. After finding an additional 691_692insAG OPTN variant, we can still only conclude that this
variant is rare. Combined analysis of our data with data from more than a dozen other studies indicates no association of
R545Q with glaucoma in most populations. Those same studies disagree in their conclusions regarding the role of M98K
in glaucoma. Our analysis of the combined data provides statistically significant evidence of association of M98K with
normal tension glaucoma in Asian populations, but not in Caucasian populations; however, the validity of this conclusion
is questionable because of large differences in allele frequencies between and within populations. It is currently not
possible to tell how much of the underlying cause of the allele frequency difference is attributable to demographic, technical, or ascertainment differences among the studies
Investigation of Known Genetic Risk Factors for Primary Open Angle Glaucoma in Two Populations of African Ancestry
Multiple genes have been associated with primary open angle glaucoma (POAG) in Caucasian populations. We now examine the association of these loci in populations of African ancestry, populations at particularly high risk for POAG
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Estrogen pathway polymorphisms in relation to primary open angle glaucoma: An analysis accounting for gender from the United States
Purpose Circulating estrogen levels are relevant in glaucoma phenotypic traits. We assessed the association between an estrogen metabolism single nucleotide polymorphism (SNP) panel in relation to primary open angle glaucoma (POAG), accounting for gender. Methods: We included 3,108 POAG cases and 3,430 controls of both genders from the Glaucoma Genes and Environment (GLAUGEN) study and the National Eye Institute Glaucoma Human Genetics Collaboration (NEIGHBOR) consortium genotyped on the Illumina 660W-Quad platform. We assessed the relation between the SNP panels representative of estrogen metabolism and POAG using pathway- and gene-based approaches with the Pathway Analysis by Randomization Incorporating Structure (PARIS) software. PARIS executes a permutation algorithm to assess statistical significance relative to the pathways and genes of comparable genetic architecture. These analyses were performed using the meta-analyzed results from the GLAUGEN and NEIGHBOR data sets. We evaluated POAG overall as well as two subtypes of POAG defined as intraocular pressure (IOP) ≥22 mmHg (high-pressure glaucoma [HPG]) or IOP 0.99). Among women, gene-based analyses revealed that the catechol-O-methyltransferase gene showed strong associations with HTG (permuted gene p≤0.001) and NPG (permuted gene p=0.01). Conclusions: The estrogen SNP pathway was associated with POAG among women
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Association of Genetic Variants With Primary Open-Angle Glaucoma Among Individuals With African Ancestry.
Importance:Primary open-angle glaucoma presents with increased prevalence and a higher degree of clinical severity in populations of African ancestry compared with European or Asian ancestry. Despite this, individuals of African ancestry remain understudied in genomic research for blinding disorders. Objectives:To perform a genome-wide association study (GWAS) of African ancestry populations and evaluate potential mechanisms of pathogenesis for loci associated with primary open-angle glaucoma. Design, Settings, and Participants:A 2-stage GWAS with a discovery data set of 2320 individuals with primary open-angle glaucoma and 2121 control individuals without primary open-angle glaucoma. The validation stage included an additional 6937 affected individuals and 14 917 unaffected individuals using multicenter clinic- and population-based participant recruitment approaches. Study participants were recruited from Ghana, Nigeria, South Africa, the United States, Tanzania, Britain, Cameroon, Saudi Arabia, Brazil, the Democratic Republic of the Congo, Morocco, Peru, and Mali from 2003 to 2018. Individuals with primary open-angle glaucoma had open iridocorneal angles and displayed glaucomatous optic neuropathy with visual field defects. Elevated intraocular pressure was not included in the case definition. Control individuals had no elevated intraocular pressure and no signs of glaucoma. Exposures:Genetic variants associated with primary open-angle glaucoma. Main Outcomes and Measures:Presence of primary open-angle glaucoma. Genome-wide significance was defined as P < 5 × 10-8 in the discovery stage and in the meta-analysis of combined discovery and validation data. Results:A total of 2320 individuals with primary open-angle glaucoma (mean [interquartile range] age, 64.6 [56-74] years; 1055 [45.5%] women) and 2121 individuals without primary open-angle glaucoma (mean [interquartile range] age, 63.4 [55-71] years; 1025 [48.3%] women) were included in the discovery GWAS. The GWAS discovery meta-analysis demonstrated association of variants at amyloid-β A4 precursor protein-binding family B member 2 (APBB2; chromosome 4, rs59892895T>C) with primary open-angle glaucoma (odds ratio [OR], 1.32 [95% CI, 1.20-1.46]; P = 2 × 10-8). The association was validated in an analysis of an additional 6937 affected individuals and 14 917 unaffected individuals (OR, 1.15 [95% CI, 1.09-1.21]; P < .001). Each copy of the rs59892895*C risk allele was associated with increased risk of primary open-angle glaucoma when all data were included in a meta-analysis (OR, 1.19 [95% CI, 1.14-1.25]; P = 4 × 10-13). The rs59892895*C risk allele was present at appreciable frequency only in African ancestry populations. In contrast, the rs59892895*C risk allele had a frequency of less than 0.1% in individuals of European or Asian ancestry. Conclusions and Relevance:In this genome-wide association study, variants at the APBB2 locus demonstrated differential association with primary open-angle glaucoma by ancestry. If validated in additional populations this finding may have implications for risk assessment and therapeutic strategies
A Common Variant in MIR182 Is Associated With Primary Open-Angle Glaucoma in the NEIGHBORHOOD Consortium
PURPOSE. Noncoding microRNAs (miRNAs) have been implicated in the pathogenesis of glaucoma. We aimed to identify common variants in miRNA coding genes (MIR) associated with primary open-angle glaucoma (POAG).
METHODS. Using the NEIGHBORHOOD data set (3853 cases/33,480 controls with European ancestry), we first assessed the relation between 85 variants in 76 MIR genes and overall POAG. Subtype-specific analyses were performed in high-tension glaucoma (HTG) and normal-tension glaucoma subsets. Second, we examined the expression of miR-182, which was associated with POAG, in postmortem human ocular tissues (ciliary body, cornea, retina, and trabecular meshwork [TM]), using miRNA sequencing (miRNA-Seq) and droplet digital PCR (ddPCR). Third, miR-182 expression was also examined in human aqueous humor (AH) by using miRNA-Seq. Fourth, exosomes secreted from primary human TM cells were examined for miR-182 expression by using miRNA-Seq. Fifth, using ddPCR we compared miR182 expression in AH between five HTG cases and five controls.
RESULTS. Only rs76481776 in MIR182 gene was associated with POAG after adjustment for multiple comparisons (odds ratio [OR] ¼ 1.23, 95% confidence interval [CI]: 1.11–1.42, P ¼ 0.0002). Subtype analysis indicated that the association was primarily in the HTG subset (OR ¼ 1.26, 95% CI: 1.08–1.47, P ¼ 0.004). The risk allele T has been associated with elevated miR-182 expression in vitro. Data from ddPCR and miRNA-Seq confirmed miR-182 expression in all examined ocular tissues and TM-derived exosomes. Interestingly, miR-182 expression in AH was 2-fold higher in HTG patients than nonglaucoma controls (P ¼ 0.03) without controlling for medication treatment.
CONCLUSIONS. Our integrative study is the first to associate rs76481776 with POAG via elevated miR-182 expression
A Common Variant in MIR182 Is Associated With Primary Open-Angle Glaucoma in the NEIGHBORHOOD Consortium
PURPOSE. Noncoding microRNAs (miRNAs) have been implicated in the pathogenesis of glaucoma. We aimed to identify common variants in miRNA coding genes (MIR) associated with primary open-angle glaucoma (POAG).
METHODS. Using the NEIGHBORHOOD data set (3853 cases/33,480 controls with European ancestry), we first assessed the relation between 85 variants in 76 MIR genes and overall POAG. Subtype-specific analyses were performed in high-tension glaucoma (HTG) and normal-tension glaucoma subsets. Second, we examined the expression of miR-182, which was associated with POAG, in postmortem human ocular tissues (ciliary body, cornea, retina, and trabecular meshwork [TM]), using miRNA sequencing (miRNA-Seq) and droplet digital PCR (ddPCR). Third, miR-182 expression was also examined in human aqueous humor (AH) by using miRNA-Seq. Fourth, exosomes secreted from primary human TM cells were examined for miR-182 expression by using miRNA-Seq. Fifth, using ddPCR we compared miR182 expression in AH between five HTG cases and five controls.
RESULTS. Only rs76481776 in MIR182 gene was associated with POAG after adjustment for multiple comparisons (odds ratio [OR] ¼ 1.23, 95% confidence interval [CI]: 1.11–1.42, P ¼ 0.0002). Subtype analysis indicated that the association was primarily in the HTG subset (OR ¼ 1.26, 95% CI: 1.08–1.47, P ¼ 0.004). The risk allele T has been associated with elevated miR-182 expression in vitro. Data from ddPCR and miRNA-Seq confirmed miR-182 expression in all examined ocular tissues and TM-derived exosomes. Interestingly, miR-182 expression in AH was 2-fold higher in HTG patients than nonglaucoma controls (P ¼ 0.03) without controlling for medication treatment.
CONCLUSIONS. Our integrative study is the first to associate rs76481776 with POAG via elevated miR-182 expression
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