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1.  Dual Sensory Impairment in Older Adults Increases the Risk of Mortality: A Population-Based Study 
PLoS ONE  2013;8(3):e55054.
Although concurrent vision and hearing loss are common in older adults, population-based data on their relationship with mortality is limited. This cohort study investigated the association between objectively measured dual sensory impairment (DSI) with mortality risk over 10 years. 2812 Blue Mountains Eye Study participants aged 55 years and older at baseline were included for analyses. Visual impairment was defined as visual acuity less than 20/40 (better eye), and hearing impairment as average pure-tone air conduction threshold greater than 25 dB HL (500–4000 Hz, better ear). Ten-year all-cause mortality was confirmed using the Australian National Death Index. After ten years, 64% and 11% of participants with DSI and no sensory loss, respectively, had died. After multivariable adjustment, participants with DSI (presenting visual impairment and hearing impairment) compared to those with no sensory impairment at baseline, had 62% increased risk of all-cause mortality, hazard ratio, HR, 1.62 (95% confidence intervals, CI, 1.16–2.26). This association was more marked in those with both moderate-severe hearing loss (>40 dB HL) and presenting visual impairment, HR 1.84 (95% CI 1.19–2.86). Participants with either presenting visual impairment only or hearing impairment only, did not have an increased risk of mortality, HR 1.05 (95% CI 0.61–1.80) and HR 1.24 (95% CI 0.99–1.54), respectively. Concurrent best-corrected visual impairment and moderate-severe hearing loss was more strongly associated with mortality 10 years later, HR 2.19 (95% CI 1.20–4.03). Objectively measured DSI was an independent predictor of total mortality in older adults. DSI was associated with a risk of death greater than that of either vision loss only or hearing loss alone.
doi:10.1371/journal.pone.0055054
PMCID: PMC3587637  PMID: 23469161
2.  Global Prevalence and Major Risk Factors of Diabetic Retinopathy 
Diabetes Care  2012;35(3):556-564.
OBJECTIVE
To examine the global prevalence and major risk factors for diabetic retinopathy (DR) and vision-threatening diabetic retinopathy (VTDR) among people with diabetes.
RESEARCH DESIGN AND METHODS
A pooled analysis using individual participant data from population-based studies around the world was performed. A systematic literature review was conducted to identify all population-based studies in general populations or individuals with diabetes who had ascertained DR from retinal photographs. Studies provided data for DR end points, including any DR, proliferative DR, diabetic macular edema, and VTDR, and also major systemic risk factors. Pooled prevalence estimates were directly age-standardized to the 2010 World Diabetes Population aged 20–79 years.
RESULTS
A total of 35 studies (1980–2008) provided data from 22,896 individuals with diabetes. The overall prevalence was 34.6% (95% CI 34.5–34.8) for any DR, 6.96% (6.87–7.04) for proliferative DR, 6.81% (6.74–6.89) for diabetic macular edema, and 10.2% (10.1–10.3) for VTDR. All DR prevalence end points increased with diabetes duration, hemoglobin A1c, and blood pressure levels and were higher in people with type 1 compared with type 2 diabetes.
CONCLUSIONS
There are approximately 93 million people with DR, 17 million with proliferative DR, 21 million with diabetic macular edema, and 28 million with VTDR worldwide. Longer diabetes duration and poorer glycemic and blood pressure control are strongly associated with DR. These data highlight the substantial worldwide public health burden of DR and the importance of modifiable risk factors in its occurrence. This study is limited by data pooled from studies at different time points, with different methodologies and population characteristics.
doi:10.2337/dc11-1909
PMCID: PMC3322721  PMID: 22301125
3.  Obesity and the Microvasculature: A Systematic Review and Meta-Analysis 
PLoS ONE  2013;8(2):e52708.
Background
Overweight and obesity are thought to significantly influence a person's risk of cardiovascular disease, possibly via its effect on the microvasculature. Retinal vascular caliber is a surrogate marker of microvascular disease and a predictor of cardiovascular events. The aim of this systematic review and meta-analysis was to determine the association between body mass index (BMI) and retinal vascular caliber.
Methods and Findings
Relevant studies were identified by searches of the MEDLINE and EMBASE databases from 1966 to August 2011. Standardized forms were used for data extraction. Among over 44,000 individuals, obese subjects had narrower arteriolar and wider venular calibers when compared with normal weight subjects, independent of conventional cardiovascular risk factors. In adults, a 1 kg/m2 increase in BMI was associated with a difference of 0.07 μm [95% CI: −0.08; −0.06] in arteriolar caliber and 0.22 μm [95% CI: 0.21; 0.23] in venular caliber. Similar results were found for children.
Conclusions
Higher BMI is associated with narrower retinal arteriolar and wider venular calibers. Further prospective studies are needed to examine whether a causative relationship between BMI and retinal microcirculation exists.
doi:10.1371/journal.pone.0052708
PMCID: PMC3566162  PMID: 23405065
4.  Genome-Wide Association Study of Retinopathy in Individuals without Diabetes 
PLoS ONE  2013;8(2):e54232.
Background
Mild retinopathy (microaneurysms or dot-blot hemorrhages) is observed in persons without diabetes or hypertension and may reflect microvascular disease in other organs. We conducted a genome-wide association study (GWAS) of mild retinopathy in persons without diabetes.
Methods
A working group agreed on phenotype harmonization, covariate selection and analytic plans for within-cohort GWAS. An inverse-variance weighted fixed effects meta-analysis was performed with GWAS results from six cohorts of 19,411 Caucasians. The primary analysis included individuals without diabetes and secondary analyses were stratified by hypertension status. We also singled out the results from single nucleotide polymorphisms (SNPs) previously shown to be associated with diabetes and hypertension, the two most common causes of retinopathy.
Results
No SNPs reached genome-wide significance in the primary analysis or the secondary analysis of participants with hypertension. SNP, rs12155400, in the histone deacetylase 9 gene (HDAC9) on chromosome 7, was associated with retinopathy in analysis of participants without hypertension, −1.3±0.23 (beta ± standard error), p = 6.6×10−9. Evidence suggests this was a false positive finding. The minor allele frequency was low (∼2%), the quality of the imputation was moderate (r2 ∼0.7), and no other common variants in the HDAC9 gene were associated with the outcome. SNPs found to be associated with diabetes and hypertension in other GWAS were not associated with retinopathy in persons without diabetes or in subgroups with or without hypertension.
Conclusions
This GWAS of retinopathy in individuals without diabetes showed little evidence of genetic associations. Further studies are needed to identify genes associated with these signs in order to help unravel novel pathways and determinants of microvascular diseases.
doi:10.1371/journal.pone.0054232
PMCID: PMC3564946  PMID: 23393555
5.  Insights into the Genetic Architecture of Early Stage Age-Related Macular Degeneration: A Genome-Wide Association Study Meta-Analysis 
PLoS ONE  2013;8(1):e53830.
Genetic factors explain a majority of risk variance for age-related macular degeneration (AMD). While genome-wide association studies (GWAS) for late AMD implicate genes in complement, inflammatory and lipid pathways, the genetic architecture of early AMD has been relatively under studied. We conducted a GWAS meta-analysis of early AMD, including 4,089 individuals with prevalent signs of early AMD (soft drusen and/or retinal pigment epithelial changes) and 20,453 individuals without these signs. For various published late AMD risk loci, we also compared effect sizes between early and late AMD using an additional 484 individuals with prevalent late AMD. GWAS meta-analysis confirmed previously reported association of variants at the complement factor H (CFH) (peak P = 1.5×10−31) and age-related maculopathy susceptibility 2 (ARMS2) (P = 4.3×10−24) loci, and suggested Apolipoprotein E (ApoE) polymorphisms (rs2075650; P = 1.1×10−6) associated with early AMD. Other possible loci that did not reach GWAS significance included variants in the zinc finger protein gene GLI3 (rs2049622; P = 8.9×10−6) and upstream of GLI2 (rs6721654; P = 6.5×10−6), encoding retinal Sonic hedgehog signalling regulators, and in the tyrosinase (TYR) gene (rs621313; P = 3.5×10−6), involved in melanin biosynthesis. For a range of published, late AMD risk loci, estimated effect sizes were significantly lower for early than late AMD. This study confirms the involvement of multiple established AMD risk variants in early AMD, but suggests weaker genetic effects on the risk of early AMD relative to late AMD. Several biological processes were suggested to be potentially specific for early AMD, including pathways regulating RPE cell melanin content and signalling pathways potentially involved in retinal regeneration, generating hypotheses for further investigation.
doi:10.1371/journal.pone.0053830
PMCID: PMC3543264  PMID: 23326517
6.  Risk Factors for Parenteral Nutrition–associated Liver Disease Following Surgical Therapy for Necrotizing Enterocolitis 
Objective
The aim of the study was to prospectively determine risk factors for the development of parenteral nutrition–associated liver disease (PNALD) in infants who underwent surgery for necrotizing enterocolitis (NEC), the most common cause of intestinal failure in children.
Patients and Methods
From February 2004 to February 2007, we diagnosed 464 infants with NEC, of whom 180 had surgery. One hundred twenty-seven patients were available for full analysis. PNALD was defined as serum direct bilirubin ≥2 mg/dL or ALT ≥2× the upper limit of normal in the absence of sepsis after ≥14 days of exposure to PN. Median
Results
Median gestational age was 26 weeks and 68% were boys. Seventy percent of the cohort developed PNALD and the incidence of PNALD varied significantly across the 6 study sites, ranging from 56% to 85% (P=0.05). Multivariable logistic regression analysis identified small-bowel resection or creation of jejunostomy (odds ratio [OR] 4.96, 95% confidence interval [CI] 1.97–12.51, P = 0.0007) and duration of PN in weeks (OR 2.37, 95% CI 1.56–3.60, P < 0.0001) as independent risk factors for PNALD. Preoperative exposure to PN was also associated with the development of PNALD; the risk of PNALD was 2.6 (95% CI 1.5–4.7; P = 0.001) times greater in patients with ≥4 weeks of preoperative PN compared with those with less preoperative PN use. Breast milk feedings, episodes of infection, and gestational age were not related to the development of PNALD.
Conclusions
The incidence of PNALD is high in infants with NEC undergoing surgical treatment. Risk factors for PNALD are related to signs of NEC severity, including the need for small-bowel resection or proximal jejunostomy, as well as longer exposure to PN. Identification of these and other risk factors can help in the design of clinical trials for the prevention and treatment of PNALD and for clinical assessment of patients with NEC and prolonged PN dependence.
doi:10.1097/MPG.0b013e31820e8396
PMCID: PMC3444282  PMID: 21464752
intestinal failure; jejunostomy; necrotizing enterocolitis; parenteral nutrition–associated liver disease; short-bowel syndrome
7.  Language barrier and its relationship to diabetes and diabetic retinopathy 
BMC Public Health  2012;12:781.
Background
Language barrier is an important determinant of health care access and health. We examined the associations of English proficiency with type-2 diabetes (T2DM) and diabetic retinopathy (DR) in Asian Indians living in Singapore, an urban city where English is the predominant language of communication.
Methods
This was a population-based, cross-sectional study. T2DM was defined as HbA1c ≥6.5%, use of diabetic medication or a physician diagnosis of diabetes. Retinal photographs were graded for the severity of DR including vision-threatening DR (VTDR). Presenting visual impairment (VI) was defined as LogMAR visual acuity > 0.30 in the better-seeing eye. English proficiency at the time of interview was assessed.
Results
The analyses included 2,289 (72.1%) English-speaking and 885 (27.9%) Tamil- speaking Indians. Tamil-speaking Indians had significantly higher prevalence of T2DM (46.2 vs. 34.7%, p < 0.001) and, among those with diabetes, higher prevalence of DR (36.0 vs. 30.6%, p < 0.001), VTDR (11.0 vs. 6.5%, p < 0.001), and VI (32.4 vs. 14.6%) than English speaking Indians. Oaxaca decomposition analyses showed that the language-related discrepancies (defined as the difference in prevalence between persons speaking different languages) in T2DM, DR, and VTDR could not be fully explained by socioeconomic measures.
Conclusions
In an English dominant society, Tamil-speaking Indians are more likely to have T2DM and diabetic retinopathy. Social policies and health interventions that address language-related health disparities may help reduce the public health impact of T2DM in societies with heterogeneous populations.
doi:10.1186/1471-2458-12-781
PMCID: PMC3462107  PMID: 22974298
English proficiency; Asian indians; Diabetes; Diabetic retinopathy; Visual impairment
8.  Pharmacodynamic analysis of tumour perfusion assessed by 15O-water-PET imaging during treatment with sunitinib malate in patients with advanced malignancies 
EJNMMI Research  2012;2:31.
Background
We evaluated pharmacodynamic changes in tumour perfusion using positron emission tomography (PET) imaging with 15O-water to assess biological response to sunitinib, a multitargeted tyrosine kinase inhibitor.
Methods
Patients with advanced malignancies received sunitinib 50 mg/day orally, once daily for 4 weeks on treatment, followed by 2 weeks off treatment, in repeated 6-week cycles. Quantitative measurement of tumour perfusion was assessed using 15O-water-PET at baseline and after 2 weeks of treatment. At least one reference tumour lesion was included in the fields of view and assessed at both time points. Patients also underwent 18 F-fluorodeoxyglucose (FDG)-PET imaging at baseline and after 2 and 4 weeks of treatment. Radiological response of the reference tumour lesion and overall radiological response were assessed at week 12. Serum pharmacokinetic and biomarker analyses were also performed.
Results
Data were available for seven patients. Compared with baseline, all patients experienced a decrease in reference tumour blood flow ranging from 20 % to 85 % and also a reduction in the FDG standard uptake value ranging from 29 % to 67 %. Six patients experienced a partial metabolic response based on FDG-PET criteria. Four patients had stable disease defined by radiological response (Response Evaluation Criteria in Solid Tumors) lasting between 4 and 12 cycles. An association between perfusion change and clinical benefit, and biomarker levels including vascular endothelial growth factor was observed.
Conclusion
Administering sunitinib to patients with advanced malignancies is associated with early biological responses, including decreased blood flow in secondary tumour deposits.
doi:10.1186/2191-219X-2-31
PMCID: PMC3468361  PMID: 22682364
sunitinib; tumour perfusion; FDG-PET.
9.  Common Genetic Determinants of Intraocular Pressure and Primary Open-Angle Glaucoma 
PLoS Genetics  2012;8(5):e1002611.
Intraocular pressure (IOP) is a highly heritable risk factor for primary open-angle glaucoma and is the only target for current glaucoma therapy. The genetic factors which determine IOP are largely unknown. We performed a genome-wide association study for IOP in 11,972 participants from 4 independent population-based studies in The Netherlands. We replicated our findings in 7,482 participants from 4 additional cohorts from the UK, Australia, Canada, and the Wellcome Trust Case-Control Consortium 2/Blue Mountains Eye Study. IOP was significantly associated with rs11656696, located in GAS7 at 17p13.1 (p = 1.4×10−8), and with rs7555523, located in TMCO1 at 1q24.1 (p = 1.6×10−8). In a meta-analysis of 4 case-control studies (total N = 1,432 glaucoma cases), both variants also showed evidence for association with glaucoma (p = 2.4×10−2 for rs11656696 and p = 9.1×10−4 for rs7555523). GAS7 and TMCO1 are highly expressed in the ciliary body and trabecular meshwork as well as in the lamina cribrosa, optic nerve, and retina. Both genes functionally interact with known glaucoma disease genes. These data suggest that we have identified two clinically relevant genes involved in IOP regulation.
Author Summary
Glaucoma is a major eye disease in the elderly and is the second leading cause of blindness worldwide. The numerous familial glaucoma cases, as well as evidence from epidemiological and twin studies, strongly support a genetic component in developing glaucoma. However, it has proven difficult to identify the specific genes involved. Intraocular pressure (IOP) is the major risk factor for glaucoma and the only target for the current glaucoma therapy. IOP has been shown to be highly heritable. We investigated the role of common genetic variants in IOP by performing a genome-wide association study. Discovery analyses in 11,972 participants and subsequent replication analyses in a further 7,482 participants yielded two common genetic variants that were associated with IOP. The first (rs11656696) is located in GAS7 at chromosome 17, the second (rs7555523) in TMCO1 at chromosome 1. Both variants were associated with glaucoma in a meta-analysis of 4 case-control studies. GAS7 and TMCO1 are expressed in the ocular tissues that are involved in glaucoma. Both genes functionally interact with the known glaucoma disease genes. These data suggest that we have identified two genes involved in IOP regulation and glaucomatous neuropathy.
doi:10.1371/journal.pgen.1002611
PMCID: PMC3342933  PMID: 22570627
10.  Impact of Migration and Acculturation on Prevalence of Type 2 Diabetes and Related Eye Complications in Indians Living in a Newly Urbanised Society 
PLoS ONE  2012;7(4):e34829.
Background
Health of migrants is a major public health challenge faced by governments and policy makers. Asian Indians are among the fastest growing migration groups across Asia and the world, but the impact of migration and acculturation on diabetes and diabetes-related eye complications among Indians living in urban Asia remains unclear.
Methodologies/Principal Findings
We evaluated the influence of migration and acculturation (i.e., migration status and length of residence) on the prevalence of type-2 diabetes mellitus (T2DM) and diabetes-related eye complications (diabetic retinopathy (DR) and cataract), among first-generation (defined as participant born in India with both parents born in India, n = 781) and second-generation (participants born in Singapore with both parents born in India, n = 1,112) Indian immigrants from a population-based study of Adult Indians in Singapore. Diabetes was defined as HbA1c≥6.5%, use of diabetic medication or a physician diagnosis of diabetes. Retinal and lens photographs were graded for the presence of DR and cataract. Compared to first generation immigrants, second generation immigrants had a higher age- and gender-standardized prevalence of T2DM (34.4% versus 29.0%, p<0.001), and, in those with T2DM, higher age- and gender-standardized prevalence of DR (31.7% versus 24.8%, p<0.001), nuclear cataract (13.6% versus 11.6%, p<0.001), and posterior sub-capsular cataract (6.4% versus 4.6%, p<0.001). Among first generation migrants, longer length of residence was associated with significantly younger age of diagnosis of diabetes and greater likelihood of having T2DM and diabetes-related eye complications.
Conclusion
Second generation immigrant Indians and longer length of residence are associated with higher prevalence of diabetes and diabetes-related complications (i.e., DR and cataract) among migrant Indians living in Singapore. These data highlight potential worldwide impacts of migration patterns on the risk and burden of diabetes.
doi:10.1371/journal.pone.0034829
PMCID: PMC3323593  PMID: 22506053
11.  Cost-effectiveness of ranibizumab in treatment of diabetic macular oedema (DME) causing visual impairment: evidence from the RESTORE trial 
Background/aims
To evaluate the cost-effectiveness of ranibizumab as either monotherapy or combined with laser therapy, compared with laser monotherapy, in the treatment of diabetic macular oedema (DME) causing visual impairment from a UK healthcare payer perspective.
Methods
A Markov model simulated long-term outcomes and costs of treating DME in one eye (BCVA ≤75 letters) based on data from the RESTORE Phase III trial. Outcomes measured in quality-adjusted life-years (QALYs) were simulated for a 15-year time horizon based on 12-month follow-up from RESTORE and published long-term data. Costs included treatment, disease monitoring, visual impairment and blindness (at 2010 price levels).
Results
Ranibizumab monotherapy resulted in a 0.17 QALY gain at an incremental cost of £4191 relative to laser monotherapy, yielding an incremental cost-effectiveness ratio (ICER) of £24 028. Probabilistic sensitivity analysis showed a 64% probability of being cost-effective at a threshold of £30 000 per QALY. Combined ranibizumab and laser therapy resulted in a 0.13 QALY gain at an incremental cost of £4695 relative to laser monotherapy (ICER £36 106; 42% probability of ICER <£30 000).
Conclusions
Based on RESTORE 1-year follow-up data, ranibizumab monotherapy appears to be cost-effective relative to laser monotherapy, the current standard of care. Cost-effectiveness of combination therapy is less certain. Ongoing studies will further inform on disease progression and the need for additional ranibizumab treatment.
doi:10.1136/bjophthalmol-2011-300726
PMCID: PMC3329632  PMID: 22399690
Ranibizumab; diabetic macular oedema; visual impairment; cost-effectiveness; macula; treatment medical; clinical trial; epidemiology; public health; vision; retina
12.  Candidate Gene Association Study for Diabetic Retinopathy in Persons with Type 2 Diabetes: The Candidate Gene Association Resource (CARe) 
Cardiovascular disease candidate genes, including genes previously associated with type 2 diabetes and diabetic nephropathy, were not associated with diabetic retinopathy, although a limited number of variants merit further investigation in larger cohorts.
Purpose.
To investigate whether variants in cardiovascular candidate genes, some of which have been previously associated with type 2 diabetes (T2D), diabetic retinopathy (DR), and diabetic nephropathy (DN), are associated with DR in the Candidate gene Association Resource (CARe).
Methods.
Persons with T2D who were enrolled in the study (n = 2691) had fundus photography and genotyping of single nucleotide polymorphisms (SNPs) in 2000 candidate genes. Two case definitions were investigated: Early Treatment Diabetic Retinopathy Study (ETDRS) grades ≥14 and ≥30. The χ2 analyses for each CARe cohort were combined by Cochran-Mantel-Haenszel (CMH) pooling of odds ratios (ORs) and corrected for multiple hypothesis testing. Logistic regression was performed with adjustment for other DR risk factors. Results from replication in independent cohorts were analyzed with CMH meta-analysis methods.
Results.
Among 39 genes previously associated with DR, DN, or T2D, three SNPs in P-selectin (SELP) were associated with DR. The strongest association was to rs6128 (OR = 0.43, P = 0.0001, after Bonferroni correction). These associations remained significant after adjustment for DR risk factors. Among other genes examined, several variants were associated with DR with significant P values, including rs6856425 tagging α-l-iduronidase (IDUA) (P = 2.1 × 10−5, after Bonferroni correction). However, replication in independent cohorts did not reveal study-wide significant effects. The P values after replication were 0.55 and 0.10 for rs6128 and rs6856425, respectively.
Conclusions.
Genes associated with DN, T2D, and vascular diseases do not appear to be consistently associated with DR. A few genetic variants associated with DR, particularly those in SELP and near IDUA, should be investigated in additional DR cohorts.
doi:10.1167/iovs.11-7510
PMCID: PMC3183981  PMID: 21873659
13.  Reflux Events Detected by pH-MII Do Not Determine Fundoplication Outcome 
Background
Because of complications and its invasive nature, fundoplication is often a treatment of last resort for children with gastroesophageal reflux. Gastroesophageal reflux testing does not always predict who will benefit from antireflux surgery. Furthermore, there are no studies to determine whether a higher preoperative reflux burden, including acid and nonacid reflux, is associated with an improved postfundoplication outcome. The aim of the study was to determine predictors of fundoplication outcome including acid and nonacid reflux burden.
Patients and Methods
We retrospectively reviewed preoperative pH-multichannel intraluminal impedance tracings and medical records of 34 patients who underwent fundoplication. Patients were categorized as improved or not improved, and the demographic and reflux characteristics were compared between groups. Multivariate analysis was performed to determine predictors of outcome.
Results
No single reflux marker, including the number of acid, nonacid, total events, or the percentage of time that reflux was in the esophagus, predicted fundoplication outcome (P >0.1). Neither a positive symptom index nor a positive symptom sensitivity index predicted postoperative improvement (P >0.4). Receiver operating characteristic curve analysis failed to reveal an ideal value to maximize sensitivity for either the symptom index or the symptom sensitivity index.
Conclusions
pH- multichannel intraluminal impedance testing may not be a useful tool in predicting fundoplication outcome.
doi:10.1097/MPG.0b013e3181b643db
PMCID: PMC3275907  PMID: 20118804
fundoplication; gastroesophageal reflux; impedance; pH probe; symptom index; symptom sensitivity index
14.  Age-Based Testing for Driver's License Renewal: Potential Implications for Older Australians 
OBJECTIVES
To investigate the effect of age-based testing (ABT) for driver’s license renewal policies among older Australians.
DESIGN
Secondary data analysis of a pooled dataset
SETTING
Community-based samples drawn from three Australian States.
PARTICIPANTS
5206 older adults aged 65 to 103 from the Dynamic Analyses to Optimise Ageing (DYNOPTA) project.
MEASUREMENTS
Included were: self-reported driving status, ABT for driver’s license renewal status, demographics, medical conditions, Mini Mental State Exam (MMSE), and visual acuity.
RESULTS
After accounting for significant demographic and health covariates, logistic regression analyses revealed that older adults required to undergo ABT were between 2.22 (95% CI= 1.35–3.57, P <.01) and 1.52 (95% CI=1.18–1.92, P<.01) times more likely to report not driving. Similar proportions of drivers with cognitive or visual impairments were found regardless of ABT status.
CONCLUSIONS
Required ABT for license renewal was associated with lower rates of driving. The proportion of drivers with probable cognitive or visual impairments was similar in those who had ABT and those who did not. Future investigation of the impact of current ABT policies on crash rates and the potential to use other scientifically designed ABT strategies, is therefore needed.
doi:10.1111/j.1532-5415.2010.03241.x
PMCID: PMC3065853  PMID: 21288232
Older drivers; Driver’s license testing; Age-based testing (ABT); DYNOPTA
15.  Common variants near CAV1 and CAV2 are associated with primary open-angle glaucoma 
Nature genetics  2010;42(10):906-909.
We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in 1,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q31 (rs4236601[A], odds ratio (OR) = 1.36, P = 5.0 × 10-10). We then replicated the association in sample sets of 2,175 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = 1.18, P = 0.0015) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.0021). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG.
doi:10.1038/ng.661
PMCID: PMC3222888  PMID: 20835238
16.  Safety and Efficacy of Ranibizumab in Diabetic Macular Edema (RESOLVE Study*) 
Diabetes Care  2010;33(11):2399-2405.
OBJECTIVE
The expression of vascular endothelial growth factor (VEGF) is elevated in diabetic macular edema (DME). Ranibizumab binds to and inhibits multiple VEGF variants. We investigated the safety and efficacy of ranibizumab in DME involving the foveal center.
RESEARCH DESIGN AND METHODS
This was a 12-month, multicenter, sham-controlled, double-masked study with eyes (age >18 years, type 1 or 2 diabetes, central retinal thickness [CRT] ≥300 μm, and best corrected visual acuity [BCVA] of 73–39 ETDRS letters [Early Treatment Diabetic Retinopathy Study]) randomly assigned to intravitreal ranibizumab (0.3 or 0.5 mg; n = 51 each) or sham (n = 49). The treatment schedule comprised three monthly injections, after which treatment could be stopped/reinitiated with an opportunity for rescue laser photocoagulation (protocol-defined criteria). After month 1, dose-doubling was permitted (protocol-defined criteria, injection volume increased from 0.05 to 0.1 ml and remained at 0.1 ml thereafter). Efficacy (BCVA and CRT) and safety were compared between pooled ranibizumab and sham arms using the full analysis set (n = 151, patients receiving ≥1 injection).
RESULTS
At month 12, mean ± SD BCVA improved from baseline by 10.3 ± 9.1 letters with ranibizumab and declined by 1.4 ± 14.2 letters with sham (P < 0.0001). Mean CRT reduction was 194.2 ± 135.1 μm with ranibizumab and 48.4 ± 153.4 μm with sham (P < 0.0001). Gain of ≥10 letters BCVA from baseline occurred in 60.8% of ranibizumab and 18.4% of sham eyes (P < 0.0001). Safety data were consistent with previous studies of intravitreal ranibizumab.
CONCLUSIONS
Ranibizumab is effective in improving BCVA and is well tolerated in DME. Future clinical trials are required to confirm its long-term efficacy and safety.
doi:10.2337/dc10-0493
PMCID: PMC2963502  PMID: 20980427
17.  A 32 kb Critical Region Excluding Y402H in CFH Mediates Risk for Age-Related Macular Degeneration 
PLoS ONE  2011;6(10):e25598.
Complement factor H shows very strong association with Age-related Macular Degeneration (AMD), and recent data suggest that multiple causal variants are associated with disease. To refine the location of the disease associated variants, we characterized in detail the structural variation at CFH and its paralogs, including two copy number polymorphisms (CNP), CNP147 and CNP148, and several rare deletions and duplications. Examination of 34 AMD-enriched extended families (N = 293) and AMD cases (White N = 4210 Indian = 134; Malay = 140) and controls (White N = 3229; Indian = 117; Malay = 2390) demonstrated that deletion CNP148 was protective against AMD, independent of SNPs at CFH. Regression analysis of seven common haplotypes showed three haplotypes, H1, H6 and H7, as conferring risk for AMD development. Being the most common haplotype H1 confers the greatest risk by increasing the odds of AMD by 2.75-fold (95% CI = [2.51, 3.01]; p = 8.31×10−109); Caucasian (H6) and Indian-specific (H7) recombinant haplotypes increase the odds of AMD by 1.85-fold (p = 3.52×10−9) and by 15.57-fold (P = 0.007), respectively. We identified a 32-kb region downstream of Y402H (rs1061170), shared by all three risk haplotypes, suggesting that this region may be critical for AMD development. Further analysis showed that two SNPs within the 32 kb block, rs1329428 and rs203687, optimally explain disease association. rs1329428 resides in 20 kb unique sequence block, but rs203687 resides in a 12 kb block that is 89% similar to a noncoding region contained in ΔCNP148. We conclude that causal variation in this region potentially encompasses both regulatory effects at single markers and copy number.
doi:10.1371/journal.pone.0025598
PMCID: PMC3192039  PMID: 22022419
18.  Ethnic and Mouse Strain Differences in Central Corneal Thickness and Association with Pigmentation Phenotype 
PLoS ONE  2011;6(8):e22103.
The cornea is a transparent structure that permits the refraction of light into the eye. Evidence from a range of studies indicates that central corneal thickness (CCT) is strongly genetically determined. Support for a genetic component comes from data showing significant variation in CCT between different human ethnic groups. Interestingly, these studies also appear to show that skin pigmentation may influence CCT. To validate these observations, we undertook the first analysis of CCT in an oculocutaneous albinism (OCA) and Ugandan cohort, populations with distinct skin pigmentation phenotypes. There was a significant difference in the mean CCT of the OCA, Ugandan and Australian-Caucasian cohorts (Ugandan: 517.3±37 µm; Caucasian: 539.7±32.8 µm, OCA: 563.3±37.2 µm; p<0.001). A meta-analysis of 53 studies investigating the CCT of different ethnic groups was then performed and demonstrated that darker skin pigmentation is associated with a thinner CCT (p<0.001). To further verify these observations, we measured CCT in 13 different inbred mouse strains and found a significant difference between the albino and pigmented strains (p = 0.008). Specific mutations within the melanin synthesis pathway were then investigated in mice for an association with CCT. Significant differences between mutant and wild type strains were seen with the nonagouti (p<0.001), myosin VA (p<0.001), tyrosinase (p = 0.025) and tyrosinase related protein (p = 0.001) genes. These findings provide support for our hypothesis that pigmentation is associated with CCT and identifies pigment-related genes as candidates for developmental determination of a non-pigmented structure.
doi:10.1371/journal.pone.0022103
PMCID: PMC3154201  PMID: 21853026
19.  The Relationship between Retinal Arteriolar and Venular Calibers Is Genetically Mediated, and Each Is Associated with Risk of Cardiovascular Disease 
Retinal arteriolar and venular calibers have a high phenotypic correlation caused by a shared genetic correlation. Identifying vessel pleiotropic genes will elucidate the nature of vessel association with specific cardiovascular disease risk factors.
Purpose.
Retinal arteriolar and venular calibers are highly heritable and associated with cardiovascular disease. This study was designed to investigate the relative influence of genetic and environmental factors on the high phenotypic correlation (r = 0.59) between these two traits and to assess the shared and specific influence of established and novel cardiovascular disease risk factors on them.
Methods.
A total of 1463 Caucasian female twins (706 monozygotic and 757 dizygotic), between 24 and 79 years of age, underwent retinal photography from which retinal arteriolar (mean, 153.75 ± 22.1 μm, SD) and venular (mean, 232.1 ± 36.6 μm) calibers were measured with semiautomated software. A bivariate heritability model was used to assess the genetic and environmental influences underlying both specific trait variance and the covariance between the vessel traits. The investigation was an assessment of phenotypic associations between retinal arteriolar and venular calibers and cardiovascular disease risk factors.
Results.
Additive genetic factors accounted for approximately three fourths of the covariance between retinal arteriolar and venular calibers within the cohort. This finding was replicated in a sample of 1981 twins from the Australian Twins Eye Study. The partial correlation showed that known risk factors accounted for only 5% of the covariance between arteriolar and venular calibers. Novel associations were found between venular caliber and β-cell function (P = 0.011) and insulin sensitivity (P = 0.002).
Conclusions.
These results suggest that future gene-mapping studies may identify pleiotropic genetic variants influencing both retinal arteriolar and venular calibers. Genetic variants associated with retinal caliber and (risk factors for) cardiovascular disease should provide new etiologic insights into this complex disease.
doi:10.1167/iovs.10-5927
PMCID: PMC3053116  PMID: 20926817
20.  A Pilot Study of Ketamine versus Midazolam/Fentanyl Sedation in Children Undergoing GI Endoscopy 
Background. Ketamine sedation has been found superior by physician report to traditional sedation regimens for pediatric endoscopy. Goal. To objectively compare sedation with ketamine versus midazolam/fentanyl for children undergoing gastrointestinal endoscopy. Study. Patients received one of two regimens and were independently monitored using a standardized rating scale. Results. There were 2 episodes of laryngospasm during ketamine sedation. Univariate analyses showed patients sedated with ketamine (n = 17) moved more (median 25% of procedure time versus 8%, P = .03) and required similar low levels of restraint (0.83% versus 0.25%, P = .4) as patients sedated with midazolam/fentanyl (n = 20). Age-adjusted analyses suggested that patients sedated with ketamine were comparably more quiet (P = .002). Conclusions. A pilot trial of ketamine at our institution was associated with episodes of laryngospasm. In addition, children sedated with ketamine moved and required restraint similarly to patients sedated with midazolam/fentanyl. Physician perceptions may be affected by the fact that children who received ketamine were less likely to vocalize distress.
doi:10.1155/2011/623710
PMCID: PMC3133434  PMID: 21760813
21.  The Prevalence of Retinal Vein Occlusion: Pooled Data from Population Studies from the United States, Europe, Asia, and Australia 
Ophthalmology  2010;117(2):313-9.e1.
Objective
To summarize the prevalence of retinal vein occlusion (RVO) from studies in the United States, Europe, Asia, and Australia.
Design
Pooled analysis using individual population-based data.
Participants
Individual participant data from population-based studies around the world that had ascertained RVO from fundus photographs.
Methods
Each study provided data on branch RVO and central RVO by age, sex, and ethnicity. Prevalence rates were directly age and sex standardized to the 2008 world population aged 30 years and older. Estimates were calculated by study and, after pooling, by ethnicity. Summary estimates included studies in which RVO was assessed from fundus photographs on ≥2 fields of both eyes.
Main Outcome Measures
Any RVO, CRVO, or BRVO.
Results
The combined pooled data contained 68,751 individuals from 15 studies, with participants’ ages ranging from 30 to 101 years. In analyses of 11 studies that assessed ≥2 fundus fields of both eyes (n=49,869), the age- and sex-standardized prevalence was 5.20 per 1000 (confidence interval [CI], 4.40–5.99) for any RVO, 4.42 per 1000 (CI, 3.65–5.19) for BRVO, and 0.80 per 1000 (CI, 0.61–0.99) for CRVO. Prevalence varied by race/ethnicity and increased with age, but did not differ by gender. The age- and sex-standardized prevalence of any RVO was 3.7 per 1000 (CI, 2.8–4.6) in whites (5 studies), 3.9 per 1000 (CI, 1.8–6.0) in blacks (1 study), 5.7 per 1000 (CI, 4.5–6.8) in Asians (6 studies), and 6.9 per 1000 (CI, 5.7–8.3) in Hispanics (3 studies). Prevalence for CRVO was lower than BRVO in all ethnic populations. On the basis of these data, an estimated 16.4 million (CI, 13.9–18.9) adults are affected by RVO, with 2.5 million (CI, 1.9–3.1) affected by CRVO and 13.9 million (CI, 11.5–16.4) affected by BRVO. Study limitations include non-uniform sampling frames in identifying study participants and in acquisition and grading of RVO data.
Conclusions
Our study provides summary data on the prevalence of RVO and suggests that approximately 16 million people may have this condition. Research on preventive and treatment strategies for this sight-threatening eye disease is needed.
doi:10.1016/j.ophtha.2009.07.017
PMCID: PMC2945292  PMID: 20022117
23.  Neurolymphomatosis: diagnosis, management, and outcomes in patients treated with rituximab 
Neuro-Oncology  2009;12(2):212-215.
Neurolymphomatosis (NL) is an uncommon syndrome of peripheral or cranial nerve root dysfunction secondary to infiltration by B-cell non-Hodgkin's lymphoma (NHL). A high index of suspicion is required as presenting symptoms are varied, conventional radiology has only modest sensitivity, and pathological diagnosis is often difficult. Treatment with chemotherapy alone has an objective response rate of 82%, although long-term outcomes are highly variable. This case series describes outcomes in four patients whose management incorporated PET scanning and the use of rituximab in combination with chemotherapy. PET scanning could often diagnose NL where other diagnostic modalities were non-diagnostic. Although combination therapy with rituximab and chemotherapy has been shown to be superior to chemotherapy alone in other forms of NHL, this does not appear to be the case in patients with NL. This may reflect the inability of rituximab to adequately penetrate into the central and peripheral nervous system. This is supported by the common finding that patients will relapse solely with NL despite on-going complete remission at sites outside the nervous system. The prognosis of these patients is poor, with the disease often following a progressive course despite treatment.
doi:10.1093/neuonc/nop021
PMCID: PMC2940573  PMID: 20150388
chemotherapy; incidence; neurolymphomatosis; PET; rituximab
24.  The role of toll-like receptor variants in acute anterior uveitis 
Molecular Vision  2011;17:2970-2977.
Purpose
Acute anterior uveitis (AAU) is the most common form of uveitis; however, while it is presumed to have an immunological basis, the precise underlying etiology remains elusive. Toll-like receptors (TLRs) have a key role in linking innate and adaptive immunity, thereby forming a molecular bridge between microbial triggers and the development of AAU. The purpose of this study was to investigate the role of TLR2 and TLR4 gene polymorphisms in the pathogenesis of AAU.
Methods
The study comprised 225 confirmed cases of idiopathic or human leukocyte antigen (HLA) B27 (subtypes B*2701-2759; HLA-B27)-related AAU and 2,534 population-based controls from the Blue Mountains Eye Study. All participants were of Anglo-Celtic descent. Blood samples were collected for DNA extraction and genotyping. A total of 16 single nucleotide polymorphisms (SNPs) were selected for analysis and either directly genotyped or imputed to cover the common variations within the TLR genes. Data were analyzed at the allelic, genotypic and haplotypic levels.
Results
Control subjects were significantly older than case subjects (p<0.0001). There was no significant difference in the gender composition between the case and control cohorts (p=0.18). One TLR2 SNP (rs11938228) was found to be associated with AAU at the allelic level (OR=1.28; p=0.017); however this association did not remain following adjustment for age and sex (p=0.067). None of the SNPs at the TLR4 locus were found to differ significantly between cases or controls, irrespective of adjustment for age and gender.
Conclusions
This study has confirmed that common TLR variants of moderate effect size do not predispose to AAU, undermining the implication of reported mutations in the selective perturbations of TLR expression and function evident in AAU.
PMCID: PMC3224833  PMID: 22128242
25.  Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis 
BMC Ophthalmology  2010;10:31.
Background
Age-related macular degeneration (AMD) is the leading cause of blindness in Western countries. Numerous risk factors have been reported but the evidence and strength of association is variable. We aimed to identify those risk factors with strong levels of evidence which could be easily assessed by physicians or ophthalmologists to implement preventive interventions or address current behaviours.
Methods
A systematic review identified 18 prospective and cross-sectional studies and 6 case control studies involving 113,780 persons with 17,236 cases of late AMD that included an estimate of the association between late AMD and at least one of 16 pre-selected risk factors. Fixed-effects meta-analyses were conducted for each factor to combine odds ratio (OR) and/or relative risk (RR) outcomes across studies by study design. Overall raw point estimates of each risk factor and associated 95% confidence intervals (CI) were calculated.
Results
Increasing age, current cigarette smoking, previous cataract surgery, and a family history of AMD showed strong and consistent associations with late AMD. Risk factors with moderate and consistent associations were higher body mass index, history of cardiovascular disease, hypertension, and higher plasma fibrinogen. Risk factors with weaker and inconsistent associations were gender, ethnicity, diabetes, iris colour, history of cerebrovascular disease, and serum total and HDL cholesterol and triglyceride levels.
Conclusions
Smoking, previous cataract surgery and a family history of AMD are consistent risk factors for AMD. Cardiovascular risk factors are also associated with AMD. Knowledge of these risk factors that may be easily assessed by physicians and general ophthalmologists may assist in identification and appropriate referral of persons at risk of AMD.
doi:10.1186/1471-2415-10-31
PMCID: PMC3009619  PMID: 21144031

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