Gregory S Hageman

University of Utah, Salt Lake City, Utah, United States

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Publications (122)617.49 Total impact

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    ABSTRACT: Purpose: To examine the fundus autofluorescence (FAF) characteristics of nascent geographic atrophy (nGA), pathological features preceding the development of drusen-associated atrophy in eyes with age-related macular degeneration (AMD) that can be visualized using high-resolution optical coherence tomography (OCT). Methods: Spectral-domain OCT (SD-OCT) and FAF imaging were performed longitudinally in 221 eyes with intermediate AMD (having at least drusen >125 μm), and 7 areas that developed drusen-associated atrophy in 5 eyes were examined and categorized with respect to FAF characteristics. These categories were then used to characterize 49 areas of nGA or drusen-associated atrophy on SD-OCT identified in a cross-sectional study with 230 participants with bilateral intermediate AMD. Results: Sequential imaging revealed that FAF characteristics in the atrophic areas could be grouped into three categories: predominantly hyperautofluorescent (hyperAF), both hyper- and hypoautofluorescence (mixed AF) or predominantly hypoautofluorescent (hypoAF). In the cross-sectional study, the FAF characteristics were significantly dependent on the type of atrophic area (P = 0.002), where areas of nGA appeared most commonly as being mixed AF (63%) while areas of drusen-associated atrophy most commonly as hypoAF (86%). Conclusions: FAF imaging revealed that areas of nGA were most commonly characterized by both hyper- and hypoautofluorescent changes, which differs from areas of drusen-associated atrophy that most often appeared hypoautofluorescent. These findings provide important insights into the FAF characteristics of areas undergoing atrophic changes in eyes still considered to be in the early stages of AMD by current methods, and thus assist in the characterization of disease severity in these early stages. Copyright © 2015 by Association for Research in Vision and Ophthalmology.
    Investigative ophthalmology & visual science. 02/2015;
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    ABSTRACT: Purpose To characterize the pathological changes preceding the development of drusen-associated atrophy in eyes with age-related macular degeneration (AMD) using spectral-domain optical coherence tomography (SD-OCT). Design Longitudinal and cross-sectional retrospective observational study. Participants A total of 181 participants with intermediate AMD in at least 1 eye (141 unilateral, 40 bilateral) were assessed longitudinally. A total of 230 participants with bilateral intermediate AMD (40 longitudinal participants with an additional 190 participants) were analyzed cross-sectionally. Methods Spectral-domain OCT, color fundus photography (CFP), near-infrared reflectance, and fundus autofluorescence imaging were performed in all participants at cross-section and every 3 months for up to 30 months in the longitudinal study. Spectral-domain OCT volume scans were examined for features that portend the development of drusen-associated atrophy, and the topography, prevalence, and risk factors of these features were determined through cross-sectional analysis. Main Outcome Measures The pathological features on SD-OCT preceding the development of drusen-associated atrophy and the characteristics of these features. Results Twenty areas from 16 eyes of 16 participants developed drusen-associated atrophy after an average of 20 months (range, 8–30 months). Spectral-domain OCT features unique in these areas included: subsidence of the outer plexiform layer (OPL) and inner nuclear layer (INL), and development of a hyporeflective wedge-shaped band within the limits of the OPL. These characteristics were termed “nascent geographic atrophy” (nGA), describing features that portend the development of drusen-associated atrophy. Cross-sectional examination of participants with bilateral intermediate AMD revealed that independent risk factors for the presence of nGA included the presence of pigmentary changes (odds ratio [OR], 16.84; 95% confidence interval [CI], 2.42–117.24) and nGA in the fellow eye (OR, 4.15; 95% CI, 1.12–15.34); nGA was present in 21.9% of participants with drusen >125 μm and pigmentary changes in both eyes. Conclusions This study identified pathological changes occurring before the development of drusen-associated atrophy using SD-OCT, which we defined as nGA. Although nGA is undetectable on CFP, it is important for determining the risk of future vision loss in AMD and could be used as an earlier surrogate end point in interventional trials targeting the early stages of AMD.
    Ophthalmology 12/2014; · 6.17 Impact Factor
  • Alan C Bird, Rachel L Phillips, Gregory S Hageman
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    ABSTRACT: IMPORTANCE Geographic atrophy (GA) is the major cause of blind registration in Western communities, although, with few exceptions, it is less common than choroidal neovascular disease. The variation of phenotype implies that age-related macular degeneration (AMD) does not follow the same course from one case to another and that phenotyping may be important before initiating a therapeutic trial. OBJECTIVE To document photoreceptor and retinal pigment epithelium (RPE) cell loss and other changes at the RPE-choroid interface in donated human eyes in which visual loss was deemed to be due to GA. DESIGN, SETTING, AND PARTICIPANTS Histological study of a consecutive series of eyes donated by individuals previously diagnosed clinically as having GA. Donors were chosen on the basis of available clinical records (from MidAmerica Transplant Services, St Louis, Missouri; the Iowa Lions Eye Bank, Iowa City; and the Utah Lions Eye Bank, Salt Lake City) and selected were those considered to have GA due to AMD. Tissues in the regions of atrophy were examined with light, electron, and autofluorescence microscopy. RESULTS In most of the 37 donors examined, there was marked loss of photoreceptor cells for variable distances distal from the edge of the GA. Rod loss was greater than cone loss. An inverse relationship existed between the quantity of autofluorescent inclusions in the RPE and the thickness of sub-RPE basal laminar deposit. Integrity of the choroid varied from one eye to another and was not related strictly to photoreceptor survival. In some eyes, photoreceptor loss existed in the absence of obvious morphological changes in the Bruch membrane or RPE. CONCLUSIONS AND RELEVANCE The findings support the view that photoreceptor loss occurs early in AMD in a proportion of cases and imply that photoreceptor-cell loss may contribute to the functional loss recorded in early stages of AMD at least in part. The variation of changes from one eye to another implies that patients selected for a specific prophylactic therapy for early AMD should be chosen on the basis of the characteristics of their disease.
    Jama Ophthalmology 03/2014; 132(3):338-45. · 3.83 Impact Factor
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    ABSTRACT: Purpose To determine whether reticular pseudodrusen (RPD) confer an increased risk of progression to late-stage age-related macular degeneration (AMD) in fellow eyes of those recently diagnosed with unilateral choroidal neovascularization (CNV). Design Retrospective study. Participants Two hundred consecutive participants with CNV secondary to AMD in 1 eye and no signs of late-stage AMD in the fellow eye. Methods Clinical examination and comprehensive retinal imaging, including spectral-domain optical coherence tomography, near-infrared reflectance (NIR), and color fundus photography, at baseline and every follow-up visit. Main Outcome Measures Incidence of geographic atrophy (GA) and CNV in the fellow eye. Results Mean age ± standard deviation was 77±7 years, and 61% of the cohort were female. Fifty-eight percent (n = 116) had RPD, 68% had drusen of 125 μm or more, 36% had pigmentary changes, 10% had both drusen of 125 μm or more and pigmentary changes, and 17% had only RPD in their fellow eyes. After a mean follow-up of 2.3 years, CNV developed in 36% of patients and GA developed in 14% of patients. Those with RPD demonstrated late-stage AMD (61% vs. 33.4%; P < 0.001) and GA (22.4% with RPD vs. 2.4% without RPD; P < 0.001) more often. The presence of reticular pseudodrusen was an independent risk factor for the development of GA (hazard ratio [HR], 4.93; P = 0.042), but not for CNV (HR, 1.19; P = 0.500), at least within the follow-up of this study. Both drusen of 125 μm or more and pigmentary changes at baseline were significant risk factors for the development of CNV and GA (HR, 1.96–11.73; P ≤ 0.020). Conclusions Reticular pseudodrusen seem to confer an increased risk of progression to GA, in addition to drusen and pigmentary changes. The presence of RPD needs to be taken into account when discussing a patient's prognosis and planning management.
    Ophthalmology 01/2014; · 5.56 Impact Factor
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    ABSTRACT: IMPORTANCE The CX3CR1 gene is implicated as a candidate gene for age-related macular degeneration (AMD) through several lines of evidence. There is uncertainty, however, as to whether common genetic variants in CX3CR1 alter risk of AMD, since prior studies have been inconsistent and mostly limited to evaluation of 2 nonsynonymous variants, T280M (rs3732378) and V249I (rs3732379). OBJECTIVE To determine if common variants in CX3CR1 predict future risk of AMD. DESIGN, SETTING, AND PARTICIPANTS Prospective nested case-control study within 5 large study populations with long-term follow-up. We measured genotypes for T280M, V249I, and 13 other common single-nucleotide polymorphisms (SNPs) of the CX3CR1 gene among people who developed AMD (n = 1110, including 369 with neovascular AMD) and 2532 age- and sex-matched controls. MAIN OUTCOMES AND MEASURES We determined the incidence rate ratios (RR) and 95% CIs for incidence of AMD for each variant and examined interactions with other AMD-associated variants and modifiable risk factors. RESULTS In additive genetic models, we identified nonsignificant associations with AMD for T280M (RR, 0.87; P = .07) and 3 other SNPs, rs2853707 (RR, 0.88; P = .07), rs12636547 (RR, 0.85; P = .10), and rs1877563 (RR, 0.84; P = .06), 1 of which, rs2853707, is positioned in the CX3CR1 promoter region and was associated with neovascular AMD (RR, 0.75; P = .03). We observed that a recessive model was a better fit to the data for some SNPs, with associations between rs11715522 and AMD (RR, 1.27; P = .03) and between rs2669845 (RR, 3.10; P = .04), rs2853707 (RR, 0.48; P = .050), and rs9868689 (RR, 0.31; P = .02) and neovascular AMD. Moreover, in exploratory analyses, we identified a number of possible interactions including between V249I and rs2669845 and dietary intake of ω-3 fatty acids (P = .004 and P = .009, respectively) for AMD; between rs2669845 and obesity (P = .03) for neovascular AMD; between T280M and complement component 3 (C3) R102G for AMD (P = .03); between rs2669845 and Y402H in complement factor H for AMD (P = .04); and between rs2669845, rs2853707, and V249I and C3 R102G for neovascular AMD (P = .008; .04; and .002, respectively). CONCLUSIONS AND RELEVANCE This study failed to identify significant associations between common CX3CR1 variants and AMD after considering the number of SNPs analyzed and multiple comparisons. However, we observed evidence consistent with recessive modes of association and that an effect of CX3CR1 variants may depend on other factors including dietary intake of ω-3 fatty acids, obesity, and genotypes at CFH Y402H and C3 R102G. If replicated in other populations, these findings would support a role for CX3CR1 in AMD but also suggest that its role may involve mechanisms that are independent of the T280M/V249I variations.
    Jama Ophthalmology 11/2013; · 3.83 Impact Factor
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    ABSTRACT: PURPOSE:: To investigate the incidence of reticular macular disease (RMD), a subphenotype of age-related macular degeneration, in multilobular geographic atrophy (GA) and its relation to GA progression. METHODS:: One hundred and fifty-seven eyes of 99 subjects with age-related macular degeneration, primary GA, and good quality autofluorescence, and/or infrared images were classified into unilobular GA (1 lesion) or multilobular GA (≥2 distinct and/or coalescent lesions). Thirty-four subjects (50 eyes) had serial imaging. The authors determined the spatiotemporal relationships of RMD to GA and GA progression rates in five macular fields. RESULTS:: 91.7% eyes (144 of 157) had multilobular GA, 95.8% of which exhibited RMD. In subjects with serial imaging, the mean GA growth rate significantly differed between the unilobular and multilobular groups (0.40 vs. 1.30 mm/year, P < 0.001). Of the macular fields in these eyes, 77.1% of fields with RMD at baseline showed subsequent GA progression, while 53.4% of fields without RMD showed progression (P < 0.001). Percentage of fields with RMD significantly correlated with GA progression rate (P = 0.01). CONCLUSION:: Autofluorescence and infrared imaging demonstrates that RMD is nearly always present with multilobular GA in age-related macular degeneration. Furthermore, GA lobules frequently develop in areas of RMD, suggesting progression of a single underlying disease process.
    Retina (Philadelphia, Pa.) 04/2013; · 2.93 Impact Factor
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    ABSTRACT: IMPORTANCE Optical coherence tomography (OCT) findings of temporal macular thinning are important in the diagnosis and prognosis of X-linked Alport syndrome (XLAS). OBJECTIVES To report OCT findings and severity of temporal macular thinning in a cohort with XLAS and to correlate these and other ocular findings with mutation genotype. DESIGN Patients with XLAS underwent genotyping for COL4A5 mutations and complete eye examinations with retinal imaging using spectral domain OCT and fundus photography. Temporal macular thinning was calculated from OCT measurements by comparing the ratio of the retinal thickness of the temporal to the nasal subfields with a published normative database. SETTING University departments of ophthalmology and nephrology. PARTICIPANTS Thirty-two patients from 24 families. MAIN OUTCOME AND MEASURES Temporal thinning index calculated from spectral domain OCT scans. RESULTS All study patients had a mutation associated with the X-linked COL4A5 gene. Eleven different mutations were identified. Eleven of 32 patients (34%) expressed the L1649R mutation. Of a total of 63 eyes with available OCT scans, 44 (70%) had severe pathological temporal macular thinning. The L1649R mutation was associated with the least amount of severe temporal macular thinning and later onset of renal failure. CONCLUSIONS AND RELEVANCE Temporal macular thinning is a prominent sign associated with XLAS, suggesting that OCT measurements are essential in the diagnosis and prognosis of the disease. The L1649R mutation in the COL4A5 gene causes a relatively mild form of XLAS characterized by late-onset renal failure and less frequent, severe temporal macular thinning relative to other COL4A5 mutations. The pathological basis for the retinal abnormalities of XLAS remains to be established.
    Jama Ophthalmology 04/2013; · 3.83 Impact Factor
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    ABSTRACT: PURPOSE: The accuracy of predicting conversion from early-stage age-related macular degeneration (AMD) to the advanced stages of choroidal neovascularization (CNV) or geographic atrophy (GA) was evaluated to determine whether inclusion of clinically relevant genetic markers improved accuracy beyond prediction using phenotypic risk factors alone. DESIGN: Cohort study. PARTICIPANTS: White, non-Hispanic subjects participating in the Age-Related Eye Disease Study (AREDS) sponsored by the National Eye Institute consented to provide a genetic specimen. Of 2415 DNA specimens available, 940 were from disease-free subjects and 1475 were from subjects with early or intermediate AMD. METHODS: DNA specimens from study subjects were genotyped for 14 single nucleotide polymorphisms (SNPs) in genes shown previously to associate with CNV: ARMS2, CFH, C3, C2, FB, CFHR4, CFHR5, and F13B. Clinical demographics and established disease associations, including age, sex, smoking status, body mass index (BMI), AREDS treatment category, and educational level, were evaluated. Four multivariate logistic models (phenotype; genotype; phenotype + genotype; and phenotype + genotype + demographic + environmental factors) were tested using 2 end points (CNV, GA). Models were fitted using Cox proportional hazards regression to use time-to-disease onset data. MAIN OUTCOME MEASURES: Brier score (measure of accuracy) was used to identify the model with the lowest prediction error in the training set. The most accurate model was subjected to independent statistical validation, and final model performance was described using area under the receiver operator curve (AUC) or C-statistic. RESULTS: The CNV prediction models that combined genotype with phenotype with or without age and smoking revealed superior performance (C-statistic = 0.96) compared with the phenotype model based on the simplified severity scale and the presence of CNV in the nonstudy eye (C-statistic = 0.89; P<0.01). For GA, the model that combined genotype with phenotype demonstrated the highest performance (AUC = 0.94). Smoking status and ARMS2 genotype had less of an impact on the prediction of GA compared with CNV. CONCLUSIONS: Inclusion of genotype assessment improves CNV prediction beyond that achievable with phenotype alone and may improve patient management. Separate assessments should be used to predict progression to CNV and GA because genetic markers and smoking status do not equally predict both end points. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.
    Ophthalmology 03/2013; · 5.56 Impact Factor
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    ABSTRACT: Age-related macular degeneration (AMD) is a common cause of blindness in older individuals. To accelerate the understanding of AMD biology and help design new therapies, we executed a collaborative genome-wide association study, including >17,100 advanced AMD cases and >60,000 controls of European and Asian ancestry. We identified 19 loci associated at P < 5 × 10-8. These loci show enrichment for genes involved in the regulation of complement activity, lipid metabolism, extracellular matrix remodeling and angiogenesis. Our results include seven loci with associations reaching P < 5 × 10-8 for the first time, near the genes COL8A1-FILIP1L, IER3-DDR1, SLC16A8, TGFBR1, RAD51B, ADAMTS9 and B3GALTL. A genetic risk score combining SNP genotypes from all loci showed similar ability to distinguish cases and controls in all samples examined. Our findings provide new directions for biological, genetic and therapeutic studies of AMD.
    Nature Genetics 03/2013; · 29.65 Impact Factor
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    ABSTRACT: PURPOSE: To investigate genetic determinants of macular pigment optical density in women from the Carotenoids in Age-Related Eye Disease Study (CAREDS), an ancillary study of the Women's Health Initiative Observational Study. METHODS: 1,585 of 2,005 CAREDS participants had macular pigment optical density (MPOD) measured noninvasively using customized heterochromatic flicker photometry and blood samples genotyped for 440 single nucleotide polymorphisms (SNPs) in 26 candidate genes related to absorption, transport, binding, and cleavage of carotenoids directly, or via lipid transport. SNPs were individually tested for associations with MPOD using least-squares linear regression. RESULTS: Twenty-one SNPs from 11 genes were associated with MPOD (P≤0.05) after adjusting for dietary intake of lutein and zeaxanthin. This includes variants in or near genes related to: zeaxanthin binding in the macula (GSTP1), carotenoid cleavage (BCMO1), cholesterol transport or uptake (SCARB1, ABCA1, ABCG5 and LIPC), long-chain omega-3 fatty acid status (ELOVL2, FADS1 and FADS2), and various maculopathies (ALDH3A2 and RPE65). The strongest association was for rs11645428 near BCMO1 (βA=0.029, P=2.2x10-4). Conditional modeling within genes and further adjustment for other predictors of MPOD, including waist circumference, diabetes, and dietary intake of fiber, resulted in 13 SNPs from 10 genes maintaining independent association with MPOD. Variation in these single gene polymorphisms accounted for 5% of the variability in MPOD (P=3.5x10-11). CONCLUSION: Our results support that MPOD is a multi-factorial phenotype associated with variation in genes related to carotenoid transport, uptake, and metabolism, independent of known dietary and health influences on MPOD.
    Investigative ophthalmology & visual science 02/2013; · 3.43 Impact Factor
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    ABSTRACT: To describe subretinal debris found on ultrastructural examination in an eye with macular telangiectasia (MacTel) type 2 and on optical coherence tomography (OCT) in a subset of patients with MacTel type 2. Blocks from the mid-periphery and temporal perifovea of an eye with clinically documented MacTel type 2 were examined with electron microscopy (EM). Cases came from the Sydney centre of the MacTel project and the practices of the authors. On EM examination, subretinal debris was found in the perifovea with accumulation of degenerate photoreceptor elements in the subretinal space. Despite the substantial subretinal debris, there was minimal retinal pigment epithelial (RPE) reaction. Focal defects were seen in the inner limiting membrane in the perifovea. Of the 65 Sydney MacTel project participants, three (5%) had prominent yellow material at the fovea. OCT revealed smooth mounds between the RPE and the ellipsoid region. The material was hyperautofluorescent. This study suggests that subretinal accumulation of photoreceptor debris may be a feature of MacTel type 2. Ultrastructural and OCT evidence of disease beyond the vasculature, involving photoreceptors and Muller cells, is presented.
    The British journal of ophthalmology 09/2012; 96(11):1404-9. · 2.92 Impact Factor
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    ABSTRACT: Age-related macular degeneration (AMD) is a major cause of blindness in older adults and has a genetically complex background. This study examines the potential association between single nucleotide polymorphisms (SNPs) in the glucose transporter 1 (SLC2A1) gene and AMD. SLC2A1 regulates the bioavailability of glucose in the retinal pigment epithelium (RPE), which might influence oxidative stress-mediated AMD pathology. Twenty-two SNPs spanning the SLC2A1 gene were genotyped in 375 cases and 199 controls from an initial discovery cohort (the Amsterdam-Rotterdam-Netherlands study). Replication testing was performed in The Rotterdam Study (the Netherlands) and study populations from Würzburg (Germany), the Age Related Eye Disease Study (AREDS; United States), Columbia University (United States), and Iowa University (United States). Subsequently, a meta-analysis of SNP association was performed. In the discovery cohort, significant genotypic association between three SNPs (rs3754219, rs4660687, and rs841853) and AMD was found. Replication in five large independent (Caucasian) cohorts (4,860 cases and 4,004 controls) did not yield consistent association results. The genotype frequencies for these SNPs were significantly different for the controls and/or cases among the six individual populations. Meta-analysis revealed significant heterogeneity of effect between the studies. No overall association between SLC2A1 SNPs and AMD was demonstrated. Since the genotype frequencies for the three SLC2A1 SNPs were significantly different for the controls and/or cases between the six cohorts, this study corroborates previous evidence that population dependent genetic risk heterogeneity in AMD exists.
    Molecular vision 03/2012; 18:657-74. · 2.25 Impact Factor
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    ABSTRACT: Please see related commentary: Age-related macular degeneration (AMD) is a leading cause of blindness that affects the central region of the retinal pigmented epithelium (RPE), choroid, and neural retina. Initially characterized by an accumulation of sub-RPE deposits, AMD leads to progressive retinal degeneration, and in advanced cases, irreversible vision loss. Although genetic analysis, animal models, and cell culture systems have yielded important insights into AMD, the molecular pathways underlying AMD's onset and progression remain poorly delineated. We sought to better understand the molecular underpinnings of this devastating disease by performing the first comparative transcriptome analysis of AMD and normal human donor eyes. RPE-choroid and retina tissue samples were obtained from a common cohort of 31 normal, 26 AMD, and 11 potential pre-AMD human donor eyes. Transcriptome profiles were generated for macular and extramacular regions, and statistical and bioinformatic methods were employed to identify disease-associated gene signatures and functionally enriched protein association networks. Selected genes of high significance were validated using an independent donor cohort. We identified over 50 annotated genes enriched in cell-mediated immune responses that are globally over-expressed in RPE-choroid AMD phenotypes. Using a machine learning model and a second donor cohort, we show that the top 20 global genes are predictive of AMD clinical diagnosis. We also discovered functionally enriched gene sets in the RPE-choroid that delineate the advanced AMD phenotypes, neovascular AMD and geographic atrophy. Moreover, we identified a graded increase of transcript levels in the retina related to wound response, complement cascade, and neurogenesis that strongly correlates with decreased levels of phototransduction transcripts and increased AMD severity. Based on our findings, we assembled protein-protein interactomes that highlight functional networks likely to be involved in AMD pathogenesis. We discovered new global biomarkers and gene expression signatures of AMD. These results are consistent with a model whereby cell-based inflammatory responses represent a central feature of AMD etiology, and depending on genetics, environment, or stochastic factors, may give rise to the advanced AMD phenotypes characterized by angiogenesis and/or cell death. Genes regulating these immunological activities, along with numerous other genes identified here, represent promising new targets for AMD-directed therapeutics and diagnostics.
    Genome Medicine 02/2012; 4(2):16. · 4.94 Impact Factor
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    ABSTRACT: To investigate the potential influences that affect visual acuity (VA) outcome in a clinic-based cohort of age-related macular degeneration (AMD) patients undergoing anti-vascular endothelial growth factor (anti-VEGF) treatment for choroidal neovascularization. Prospective interventional case series. Patients with subfoveal choroidal neovascularization (CNV) secondary to AMD were prospectively recruited. A detailed questionnaire was given to patients at time of enrollment, to collect information relating to demographics, history of visual symptoms, visual acuity (VA), and treatment scheduling. Delay from symptoms to treatment ("Treatment delay") was measured in terms of weeks and analyzed in tertiles. Information pertaining to treatment outcomes was collected over a 6-month period. One hundred eighty-five eyes of 185 patients were recruited into the study. Longer delay from first symptoms suggestive of CNV to first injection was a significant predictor (P=.015) of poorer treatment outcome, when controlling for age, sex, and baseline VA. Patients with a delay in treatment of 21 weeks or more compared to a delay of 7 weeks or less had an odds ratio of 2.62 (1.20, 5.68) for worsening vision after treatment. Patients experiencing a longer delay between their first symptoms of CNV and their first anti-VEGF treatment have a significantly lower chance of improving vision at 6 months following anti-VEGF therapy. It is critical that this information reach those at potential vision loss from AMD, in order that prompt treatment may be instituted, to maximize the benefits of anti-VEGF treatment.
    American Journal of Ophthalmology 01/2012; 153(4):678-86, 686.e1-2. · 4.02 Impact Factor
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    ABSTRACT: We used the comparative proteomic technique iTRAQ coupled with offline 2DLC-MS/MS to analyze a rare specimen of the poorly understood, potentially blinding ophthalmic condition Macular Telangiectasia type 2 (MacTel type 2). We refined the technique using an internal standard consisting of pooled samples for each iTRAQ experiment to allow for multiple comparisons between different regions of the retina and different tissue donors. A total of 594 nonredundant proteins were identified in the retina and 168 in the vitreous, of which approximately half were found in significantly different abundance in the various comparisons made. The most prominent differences were found within the glycolytic pathway, where 8 proteins were reduced in the diseased macula compared with peripheral retina of the same eye, and 10 were also reduced in comparison with the macula of a control eye. Furthermore, Müller cell-associated proteins, including GFAP, VIME, and GLNA, were also reduced in the diseased macula, consistent with a link between the glycolytic pathway and Müller cells. These changes were validated by Western blotting and immunohistochemical studies. Proteomic analysis of the vitreous revealed an increase of proteins that were reduced in the retina. This supports proteomic analysis of the more easily available vitreous, which may reveal retina-specific protein changes associated with disease. Furthermore, our study has highlighted changes in the glycolytic pathway as a possible component of MacTel type 2 pathobiology.
    Journal of Proteome Research 11/2011; 11(2):537-53. · 5.06 Impact Factor
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    ABSTRACT: ROBO1 is a strong candidate gene for age-related macular degeneration (AMD) based upon its location under a linkage peak on chromosome 3p12, its expression pattern, and its purported function in a pathway that includes RORA, a gene previously associated with risk for neovascular AMD. Previously, we observed that expression of ROBO1 and RORA is down-regulated among wet AMD cases, as compared to their unaffected siblings. Thus, we hypothesized that contribution of association signals in ROBO1, and interaction between these two genes may be important for both wet and dry AMD. We evaluated association of 19 single nucleotide polymorphisms (SNPs) in ROBO1 with wet and dry stages of AMD in a sibling cohort and a Greek case-control cohort containing 491 wet AMD cases, 174 dry AMD cases and 411 controls. Association signals and interaction results were replicated in an independent prospective cohort (1070 controls, 164 wet AMD cases, 293 dry AMD cases). The most significantly associated ROBO1 SNPs were rs1387665 under an additive model (meta P = 0.028) for wet AMD and rs9309833 under a recessive model (meta P = 6 × 10(-4)) for dry AMD. Further analyses revealed interaction between ROBO1 rs9309833 and RORA rs8034864 for both wet and dry AMD (interaction P<0.05). These studies were further supported by whole transcriptome expression profile studies from 66 human donor eyes and chromatin immunoprecipitation assays from mouse retinas. These findings suggest that distinct ROBO1 variants may influence the risk of wet and dry AMD, and the effects of ROBO1 on AMD risk may be modulated by RORA variants.
    PLoS ONE 10/2011; 6(10):e25775. · 3.53 Impact Factor
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    ABSTRACT: Vitamin D has been shown to have anti-angiogenic properties and to play a protective role in several types of cancer, including breast, prostate and cutaneous melanoma. Similarly, vitamin D levels have been shown to be protective for risk of a number of conditions, including cardiovascular disease and chronic kidney disease, as well as numerous autoimmune disorders such as multiple sclerosis, inflammatory bowel diseases and type 1 diabetes mellitus. A study performed by Parekh et al. was the first to suggest a role for vitamin D in age-related macular degeneration (AMD) and showed a correlation between reduced serum vitamin D levels and risk for early AMD. Based on this study and the protective role of vitamin D in diseases with similar pathophysiology to AMD, we examined the role of vitamin D in a family-based cohort of 481 sibling pairs. Using extremely phenotypically discordant sibling pairs, initially we evaluated the association of neovascular AMD and vitamin D/sunlight-related epidemiological factors. After controlling for established AMD risk factors, including polymorphisms of the genes encoding complement factor H (CFH) and age-related maculopathy susceptibility 2/HtrA serine peptidase (ARMS2/HTRA1), and smoking history, we found that ultraviolet irradiance was protective for the development of neovascular AMD (p = 0.001). Although evaluation of serum vitamin D levels (25-hydroxyvitamin D [25(OH)D]) was higher in unaffected individuals than in their affected siblings, this finding did not reach statistical significance. Based on the relationship between ultraviolet irradiance and vitamin D production, we employed a candidate gene approach for evaluating common variation in key vitamin D pathway genes (the genes encoding the vitamin D receptor [VDR]; cytochrome P450, family 27, subfamily B, polypeptide 1 [CYP27B1]; cytochrome P450, family 24, subfamily A, polypeptide 1 [CYP24A1]; and CYP27A1) in this same family-based cohort. Initial findings were then validated and replicated in the extended family cohort, an unrelated case-control cohort from central Greece and a prospective nested case-control population from the Nurse's Health Study and Health Professionals Follow-Up Studies, which included patients with all subtypes of AMD for a total of 2,528 individuals. Single point variants in CYP24A1 (the gene encoding the catabolising enzyme of the vitamin D pathway) were demonstrated to influence AMD risk after controlling for smoking history, sex and age in all populations, both separately and, more importantly, in a meta-analysis. This is the first report demonstrating a genetic association between vitamin D metabolism and AMD risk. These findings were also supplemented with expression data from human donor eyes and human retinal cell lines. These data not only extend previous biological studies in the AMD field, but further emphasise common antecedents between several disorders with an inflammatory/immunogenic component such as cardiovascular disease, cancer and AMD.
    Human genomics 10/2011; 5(6):538-68.
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    ABSTRACT: Predictive tests for estimating the risk of developing late-stage neovascular age-related macular degeneration (AMD) are subject to unique challenges. AMD prevalence increases with age, clinical phenotypes are heterogeneous and control collections are prone to high false-negative rates, as many control subjects are likely to develop disease with advancing age. Risk prediction tests have been presented previously, using up to ten genetic markers and a range of self-reported non-genetic variables such as body mass index (BMI) and smoking history. In order to maximise the accuracy of prediction for mainstream genetic testing, we sought to derive a test comparable in performance to earlier testing models but based purely on genetic markers, which are static through life and not subject to misreporting. We report a multicentre assessment of a larger panel of single nucleotide polymorphisms (SNPs) than previously analysed, to improve further the classification performance of a predictive test to estimate the risk of developing choroidal neovascular (CNV) disease. We developed a predictive model based solely on genetic markers and avoided inclusion of self-reported variables (eg smoking history) or non-static factors (BMI, education status) that might otherwise introduce inaccuracies in calculating individual risk estimates. We describe the performance of a test panel comprising 13 SNPs genotyped across a consolidated collection of four patient cohorts obtained from academic centres deemed appropriate for pooling. We report on predictive effect sizes and their classification performance. By incorporating multiple cohorts of homogeneous ethnic origin, we obtained >80 per cent power to detect differences in genetic variants observed between cases and controls. We focused our study on CNV, a subtype of advanced AMD associated with a severe and potentially treatable form of the disease. Lastly, we followed a two-stage strategy involving both test model development and test model validation to present estimates of classification performance anticipated in the larger clinical setting. The model contained nine SNPs tagging variants in the regulators of complement activation (RCA) locus spanning the complement factor H (CFH), complement factor H-related 4 (CFHR4), complement factor H-related 5 (CFHR5) and coagulation factor XIII B subunit (F13B) genes; the four remaining SNPs targeted polymorphisms in the complement component 2 (C2), complement factor B (CFB), complement component 3 (C3) and age-related maculopathy susceptibility protein 2 (ARMS2) genes. The pooled sample size (1,132 CNV cases, 822 controls) allowed for both model development and model validation to confirm the accuracy of risk prediction. At the validation stage, our test model yielded 82 per cent sensitivity and 63 per cent specificity, comparable with metrics reported with earlier testing models that included environmental risk factors. Our test had an area under the curve of 0.80, reflecting a modest improvement compared with tests reported with fewer SNPs.
    Human genomics 07/2011; 5(5):420-40.
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    ABSTRACT: Anti-vascular endothelial growth factor (anti-VEGF) drugs have dramatically improved the treatment of neovascular AMD. In pivotal studies, almost 90% of patients maintain vision, with approximately 30% showing significant improvement. Despite these successes, 10% to 15% of patients continue to lose vision, even with treatment. It has been reported that variants in some AMD-associated genes influence treatment outcome. This study showed an association of treatment outcome with variants in the apolipoprotein E (APOE) gene. One hundred ninety-two patients receiving anti-VEGF treatment for subfoveal choroidal neovascularization secondary to AMD were enrolled. Information on demographics, lesion characteristics, delay until treatment, visual acuity (VA), and number of treatments was collected, and variants of APOE were assessed in all patients at baseline. Best corrected logarithm of the minimum angle of resolution (logMAR) VA was recorded in all patients. The presence of the APOE ε4 allele was associated with improved treatment outcome at 3 (P = 0.02) and 12 (P = 0.06) months, compared with the presence of the ε2 allele, after adjustment for baseline acuity, treatment delay after first symptoms, age, and sex. Patients with an APOE ε4 allele had an odds ratio (OR) of 4.04 (95% confidence interval [CI], 1.11-14.70) for a 2-line gain in vision from baseline at 3 months (P = 0.03) and an OR of 2.54 (95% CI, 0.61-10.52; P = 0.20) at 12 months after treatment, based on multivariate analysis. In patients with neovascular AMD, the presence of the APOE ε4 allele conferred significantly better visual outcomes after anti-VEGF treatment than did the ε2 allele. These findings suggest a possible role for a personalized approach to treatment with anti-VEGF.
    Investigative ophthalmology & visual science 06/2011; 52(7):4072-9. · 3.43 Impact Factor
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    ABSTRACT: The ultrastructural appearance of retinal capillaries can yield important information about disease mechanisms, but is not well characterised in human post mortem samples. We therefore aimed to create a baseline for the appearance of capillaries and establish how this is influenced by post mortem fixation delays and donor age. Electron microscopy was used to characterise retinal capillaries in 20 anonymous donors (with no known eye diseases) of various ages and with various post mortem fixation delays. In addition, samples from six patients with conditions that are known to affect the retinal vasculature (four cases of type 2 diabetes without diabetic retinopathy, one case of diabetic retinopathy and one case of macular telangiectasia type 2) were analysed. Vacuoles were found in capillary basement membranes at the vessel-glia interface in all samples, from both the normal and disease cases. Vacuole frequency increased with donor age but was not influenced by post mortem fixation delays. Vacuoles in the basement membrane are a normal feature of adult human retinal capillaries and do not indicate disease. Their incidence increases with age and might be a contributing factor to late-onset pathologies of the retinal vasculature.
    The British journal of ophthalmology 05/2011; 95(9):1316-22. · 2.92 Impact Factor

Publication Stats

7k Citations
617.49 Total Impact Points


  • 2009–2015
    • University of Utah
      • • John Moran Eye Center
      • • Department of Ophthalmology and Visual Sciences
      Salt Lake City, Utah, United States
  • 2013
    • Sequenom, Inc.
      San Diego, California, United States
  • 2012
    • Sydney Hospital & Sydney Eye Hospital
      Sydney, New South Wales, Australia
    • Royal Victorian Eye and Ear Hospital
      Melbourne, Victoria, Australia
  • 1999–2012
    • University of Iowa
      • Department of Ophthalmology and Visual Sciences
      Iowa City, IA, United States
  • 2011
    • Harvard Medical School
      Boston, Massachusetts, United States
  • 2006
    • Wills Eye Institute
      Philadelphia, Pennsylvania, United States
  • 2000–2006
    • University of California, Santa Barbara
      • Neuroscience Research Institute
      Santa Barbara, CA, United States
  • 2004
    • University of Melbourne
      • Centre for Eye Research Australia
      Melbourne, Victoria, Australia
  • 1988–2000
    • Keck School of Medicine USC
      Los Angeles, California, United States
  • 1991–1997
    • Washington University in St. Louis
      • Department of Ophthalmology and Visual Sciences
      Saint Louis, MO, United States
    • Saint Louis University
      • School of Medicine
      Saint Louis, MI, United States
  • 1995
    • Salt Lake City Community College
      Salt Lake City, Utah, United States
  • 1994
    • Johns Hopkins Medicine
      Baltimore, Maryland, United States
  • 1990–1994
    • Stanford University
      • Department of Ophthalmology
      Stanford, CA, United States
  • 1993
    • Doheny Eye Institute
      Los Angeles, California, United States
  • 1986–1991
    • University of Southern California
      • • Department of Medicine
      • • Department of Ophthalmology
      • • Department of Cell Biology and Anatomy
      Los Angeles, CA, United States
  • 1989
    • University of Missouri - St. Louis
      Saint Louis, Michigan, United States