Profile of ocular trauma in the Solomon Islands.

BACKGROUND: The objective of this study was to characterize the causes of ocular trauma and determine the risk factors for infection and vision loss following ocular trauma in the Solomon Islands. DESIGN: A prospective clinic-based study. PARTICIPANTS: A total of 507 patients with ocular trauma who were reviewed at the National Referral Hospital in Honiara or one of five provincial eye clinics were included. METHODS: An interview-based questionnaire to determine the circumstances of ocular trauma, and an ocular examination to elicit the trauma sustained,infectious sequelae and the visual outcome. MAIN OUTCOME MEASURE: Visual acuity. RESULTS: Males were significantly more likely to have ocular trauma than females (P = 0.01). The major cause of ocular trauma in young boys and girls was being poked by a stick, followed by lime burns in young boys. For both genders, physical violence resulted in most injuries across all adult age groups. Microbial keratitis complicated 4.4% of ocular trauma. Monocular vision impairment (<6/18) occurred in 5.5% of participants and was more likely to occur if female (P = 0.02). CONCLUSIONS: Ocular trauma is a significant cause of visual morbidity in the Solomon Islands. The results from this prospective study provide a basis for planning blindness prevention programmes in the Western Pacific.

Economic growth and obesity: an interesting relationship with world-wide implications.

The prosperity of a country, commonly measured in terms of its annual per capita Gross Domestic Product (GDP), has different relationships with population levels of body weight and happiness, as well as environmental impacts such as carbon emissions. The aim of this study was to examine these relationships and to try to find a level of GDP, which provides for sustainable economic activity, optimal happiness and healthy levels of mean body mass index (BMI). Spline regression analyses were conducted using national indices from 175 countries: GDP, adult BMI, mean happiness scores, and carbon footprint per capita for the year 2007. Results showed that GDP was positively related to BMI and happiness up to ∼$US3000 and ∼$5000 per capita respectively, with no significant relationships beyond these levels. GDP was also positively related to CO(2) emissions with a recognised sustainable carbon footprint of less than 5 tonnes per capita occurring at a GDP of <$US15,000. These findings show that a GDP between $US5 and $15,000 is associated with greater population happiness and environmental stability. A mean BMI of 21-23 kg/m(2), which minimises the prevalence of underweight and overweight in the population then helps to define an ideal position in relation to growth, which few countries appear to have obtained. Within a group of wealthy countries (GDP>$US30,000), those with lower income inequalities and more regulated (less liberal) market systems had lower mean BMIs.

Is diabetic retinopathy related to subclinical cardiovascular disease?

OBJECTIVE: Persons with diabetic retinopathy (DR) have an increased risk of clinical cardiovascular events. This study aimed to determine whether DR is associated with a range of measures of subclinical cardiovascular disease (CVD) in persons without clinical CVD. DESIGN: Population-based, cross-sectional epidemiologic study. PARTICIPANTS: Nine hundred twenty-seven persons with diabetes without clinical CVD in the Multi-Ethnic Study of Atherosclerosis. METHODS: Diabetic retinopathy was ascertained from retinal photographs according to modification of the Airlie House Classification system. Vision-threatening DR (VTDR) was defined as severe nonproliferative DR, proliferative DR, or clinically significant macular edema. Subclinical CVD measures were assessed and defined as follows: high coronary artery calcium (CAC) score, defined as CAC score of 400 or more; low ankle-brachial index (ABI), defined as ABI of less than 0.9; high ABI, defined as ABI of 1.4 or more; high carotid intima-media thickness (IMT), defined as highest 25% of IMT; and carotid stenosis, defined as more than 25% stenosis or presence of carotid plaque. MAIN OUTCOME MEASURES: Associations between DR and subclinical CVD measures. RESULTS: The prevalence of DR and VTDR in this sample was 30.0% and 7.2%, respectively, and VTDR was associated with a high CAC score (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.15-4.73), low ABI (OR, 2.54; 95% CI, 1.08-5.99), and high ABI (OR, 12.6; 95% CI, 1.14-140.6) after adjusting for risk factors including hemoglobin A1c level and duration of diabetes. The association between VTDR and high CAC score remained significant after further adjustment for hypoglycemic, antihypertensive, and cholesterol-lowering medications. Diabetic retinopathy was not significantly associated with measures of carotid artery disease. CONCLUSIONS: In persons with diabetes without a history of clinical CVD, the presence of advanced-stage DR is associated with subclinical coronary artery disease. These findings emphasize the need to be careful about the use of anti-vascular endothelial growth factor for the treatment of DR.

Retinopathy signs in people without diabetes: the multi-ethnic study of atherosclerosis.

OBJECTIVE: To describe the prevalence of retinopathy and associations with cardiovascular risk factors in persons without diabetes in 4 racial/ethnic groups (white, black, Hispanic, and Chinese). DESIGN: Population-based, cross-sectional study. PARTICIPANTS: We included 6176 subjects aged 45-84 years without diabetes, selected from 6 United States communities. METHODS: Fundus images were taken using 45° digital camera through dark-adapted pupils and were graded for retinopathy as defined by the Early Treatment Diabetic Retinopathy Study severity scale: microaneurysms, hemorrhages, cotton wool spots, intraretinal microvascular abnormalities, hard exudates, venous beading, and new vessels. MAIN OUTCOME MEASURES: Retinopathy and the association with cardiovascular risk factors. RESULTS: Prevalence rates of retinopathy in persons without diabetes were 12.5% overall, varying from 11.9% (white), 13.9% (black), 12.6% (Hispanic), to 17.2% (Chinese). Hypertension was strongly associated with retinopathy (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.23-1.75). After adjusting for age, gender, race, and other parameters, smoking (OR, 1.50; 95% CI, 1.09-2.06) and increased internal carotid intima media thickness (OR, 1.22; 95% CI, 1.05-1.41) were associated with retinopathy. A range of serum inflammatory factors were examined, but none were found to be significant. CONCLUSIONS: Retinopathy in persons without diabetes is common, varies with race/ethnicity, and associated with cardiovascular risk factors, including hypertension, smoking, and carotid artery intima media thickness.

Four novel Loci (19q13, 6q24, 12q24, and 5q14) influence the microcirculation in vivo.

There is increasing evidence that the microcirculation plays an important role in the pathogenesis of cardiovascular diseases. Changes in retinal vascular caliber reflect early microvascular disease and predict incident cardiovascular events. We performed a genome-wide association study to identify genetic variants associated with retinal vascular caliber. We analyzed data from four population-based discovery cohorts with 15,358 unrelated Caucasian individuals, who are members of the Cohort for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and replicated findings in four independent Caucasian cohorts (n  =  6,652). All participants had retinal photography and retinal arteriolar and venular caliber measured from computer software. In the discovery cohorts, 179 single nucleotide polymorphisms (SNP) spread across five loci were significantly associated (p<5.0×10(-8)) with retinal venular caliber, but none showed association with arteriolar caliber. Collectively, these five loci explain 1.0%-3.2% of the variation in retinal venular caliber. Four out of these five loci were confirmed in independent replication samples. In the combined analyses, the top SNPs at each locus were: rs2287921 (19q13; p  =  1.61×10(-25), within the RASIP1 locus), rs225717 (6q24; p = 1.25×10(-16), adjacent to the VTA1 and NMBR loci), rs10774625 (12q24; p  =  2.15×10(-13), in the region of ATXN2,SH2B3 and PTPN11 loci), and rs17421627 (5q14; p = 7.32×10(-16), adjacent to the MEF2C locus). In two independent samples, locus 12q24 was also associated with coronary heart disease and hypertension. Our population-based genome-wide association study demonstrates four novel loci associated with retinal venular caliber, an endophenotype of the microcirculation associated with clinical cardiovascular disease. These data provide further insights into the contribution and biological mechanisms of microcirculatory changes that underlie cardiovascular disease.

Long-term refractive outcomes and stability after excimer laser surgery for myopia.

PURPOSE: To evaluate the long-term refractive outcomes of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for myopia. SETTING: Centre for Eye Research Australia, Melbourne, Australia. DESIGN: Comparative case series. METHODS: Preoperative baseline refractions in eyes having PRK, LASIK, or both at 1 multisurgeon center were analyzed from patient databases. Two- to 13-year follow-up data were analyzed and compared with 1-month postoperative visual outcomes. RESULTS: The study evaluated 389 eyes (229 patients). In the PRK group, the mean preoperative spherical equivalent (SE) was -4.05 diopters (D) ± 1.17 (SD) in eyes with low to moderate myopia and -7.97 ± 2.00 D in eyes with high myopia (P = .009) and in the LASIK group, -3.98 ± 1.27 D and -7.64 ± 1.66 D, respectively (P = .008). At the last visit, the mean SE in the PRK group was -0.64 ± 0.83 D in eyes with low to moderate myopia and -1.06 ± 1.74 D in eyes with high myopia (P = .73) and in the LASIK group, -0.33 ± 0.59 D and -0.63 ± 0.90 D, respectively (P = .68). At the end of the study, 45.9% of eyes with low to moderate myopia and 25.0% with high myopia in the PRK group and 64.8% and 37.3%, respectively, in the LASIK group were within ± 0.50 D of the attempted correction. CONCLUSIONS: Laser refractive surgery effectively treated all levels of myopia. Refractive stability was achieved within 1 year postoperatively, with LASIK showing better stability than PRK for up to 6 to 9 years.

Analysis of glutathione S-transferase Pi isoform (GSTP1) single-nucleotide polymorphisms and macular telangiectasia type 2.

Recent imaging studies have suggested that macular pigment is decreased centrally in macular telangiectasia type 2 (MT2). The uptake of xanthophyll pigment into the macula is thought to be facilitated by a xanthophyll-binding protein (XBP). The Pi isoform of glutathione S-transferase (GSTP1) represents one such XBP with high binding affinity. This case-control study aimed to determine whether two common single-nucleotide polymorphisms (SNPs) of GSTP1 were associated with MT2. DNA samples from 39 cases and 21 controls were collected. Two polymorphic sites of Ile105Val and Ala114Val in exons 5 and 6 respectively, of the GSTP1 gene were analysed. Comparison of alleles and genotypes between cases and controls indicated that there were no statistically significant differences for either the Ile105Val SNP (P=0.43) or the Ala114Val SNP (P=0.85), or for any combinations; however, the homozygous at-risk genotype (GG) of the Ile105Val SNP was present in 8% of cases but absent in controls. This study found no statistically significant association between two common GSTP1 SNPs and MT2; however, a trend towards a greater frequency of the GG genotype of the Ile105Val SNP in cases is of great interest. The biological plausibility of disturbed macular pigment uptake in MT2 makes GSTP1 an excellent candidate gene. Further investigation is warranted in future studies of MT2.

Retinal vascular caliber and brachial flow-mediated dilation: the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND PURPOSE: Retinal vascular caliber changes have been shown to predict stroke, but the underlying mechanism of this association is unknown. We examined the relationship between retinal vascular caliber with brachial flow-mediated dilation (FMD), a measure of systemic endothelial function. METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based study of persons 45 to 84 years of age residing in 6 US communities free of clinical cardiovascular disease at baseline. Brachial FMD data were collected at baseline (July 2000 to June 2002), and retinal vascular caliber was measured from digital retinal photographs at the second examination, immediately after the first (August 2002 to January 2004). Data were available for 2851 participants for analysis. RESULTS: The mean brachial FMD was 4.39+/-2.79%. After adjusting for age and gender, brachial FMD was reduced in persons with wider retinal venular caliber (changes in FMD -0.25, 95% CI, -0.36, - 0.13; P<0.001, per SD increase in venular caliber). This relationship persists after adjusting for systolic blood pressure, serum total cholesterol, use of lipid-lowering and antihypertensive medication, body mass index, current smoking status, and hemoglobinA(1C) (-0.18; 95% CI -0.30, - 0.06; P=0.004, per SD increase in venular caliber). Brachial FMD was not associated with retinal arteriolar caliber. CONCLUSIONS: Persons with wider retinal venules have reduced brachial FMD, independent of other vascular risk factors. This suggests that retinal venular caliber, previously shown to predict stroke, may be a marker of underlying systemic endothelial dysfunction.

An intergenic region between the tagSNP rs3793917 and rs11200638 in the HTRA1 gene indicates association with age-related macular degeneration.

PURPOSE: There is still a debate as to whether the LOC387715 or HTRA1 genes represent the key significant association identified with age-related macular degeneration (AMD) on the long arm of chromosome 10, region 26. METHODS: An Australian patient cohort was genotyped by using tagged single nucleotide polymorphisms (tSNPs) to identify a causal SNP within this region. RESULTS: Multiple tSNPs across the region showed association with AMD with the tSNP rs3793917 (odds ratio [OR], 3.45; 95% confidence interval [CI], 2.36-5.05, P = 2.8 × 10(-13)) having the highest association with AMD. This tSNP occurred in the intergenic region between the LOC387715 and HTRA1 genes. A second tSNP rs2672587 (OR, 2.92; 95% CI, 2.04-4.17; P = 7.7 × 10(-11)) located in intron 1 of the HTRA1 gene had the second highest association with AMD. After logistic regression analysis, the only tSNP to survive covariate testing was rs3793917, which occurred in the same LD block as the HTRA1 promoter SNP rs11200638 (r(2) = 0.88, D' = 0.97). CONCLUSIONS: The findings indicate that the intergenic region between the tSNP rs3793917 and the SNP rs11200638 in the HTRA1 gene is the most likely site explaining the significant association with AMD.

Evidence of early retinal microvascular changes in patients with type 2 diabetes and depression.

OBJECTIVE: To examine retinal vascular caliber, an indicator of early microvascular disease and depression in patients with Type 2 diabetes. METHODS: We conducted a clinic-based study, comparing participants with Type 2 diabetes with major depression (n = 43), without depression (n = 49), and healthy controls without diabetes or depression (n = 54). Retinal vascular caliber was measured from digital photographs. Depression status was determined, using standardized clinical assessment. RESULTS: After adjusting for age and gender, participants with diabetes and depression had larger arteriolar and venular calibers (147.7 microm for arteriolar and 215.7 microm for venular calibers) than participants with diabetes but without depression (143.3 microm and 213.9 microm) and healthy controls (135.8 microm and 202.5 microm, p for trend = .002 for arteriolar and p = .02 for venular caliber). In multivariate models adjusting for duration of diabetes, systolic blood pressure, cigarette smoking, serum glucose, Cerebrovascular Risk Factor Scale, Cumulative Illness Rating Scale, and retinopathy levels, this relationship remained significant for retinal arterioles (p = .02) but not for retinal venules (p = .10). CONCLUSIONS: These data show that patients with Type 2 diabetes with major depression have wider retinal arterioles, supporting the concept that depression is associated with early microvascular changes in Type 2 diabetes.

Retinal vascular fractal dimension and risk of early diabetic retinopathy: A prospective study of children and adolescents with type 1 diabetes.

OBJECTIVE: To examine the prospective association of retinal vascular fractal dimension with diabetic retinopathy risk in young people with type 1 diabetes. RESEARCH DESIGN AND METHODS: This was a hospital-based prospective study of 590 patients aged 12-20 years with type 1 diabetes free of retinopathy at baseline. All patients had seven-field retinal photographs taken of both eyes. Incident retinopathy was ascertained from retinal photographs taken at follow-up visits. Fractal dimension was measured from baseline photographs using a computer-based program following a standardized protocol. RESULTS: Over a mean +/- SD follow-up period of 2.9 +/- 2.0 years, 262 participants developed mild nonproliferative diabetic retinopathy (15.0 per 100 person-years). After adjusting for age, sex, diabetes duration, A1C, and other risk factors, we found no association between retinal vascular fractal dimension and incident retinopathy. CONCLUSIONS: Retinal vascular fractal dimension was not associated with incident early diabetic retinopathy in this sample of children and adolescents with type 1 diabetes.

Inflammatory, hemostatic, and other novel biomarkers for diabetic retinopathy: the multi-ethnic study of atherosclerosis.

OBJECTIVE: There are conflicting data regarding relationships of systemic biomarkers of inflammation, hemostasis, and homocysteine with diabetic retinopathy. We examined these relationships in the Multi-Ethnic Study of Atherosclerosis. RESEARCH DESIGN AND METHODS: A total of 921 participants with diabetes were included. Diabetic retinopathy was graded from retinal photographs. We defined two outcomes: any diabetic retinopathy and vision-threatening diabetic retinopathy (severe nonproliferative diabetic retinopathy or worse). Systemic markers analyzed were C-reactive protein, homocysteine, fibrinogen, plasmin-alpha(2)-antiplasmin complex (PAP), interleukin-6, d-dimer, factor VIII, serum creatinine, and urinary albumin-to-creatinine (UAC) ratio. RESULTS: Prevalence of diabetic retinopathy was 33.2% and vision-threatening diabetic retinopathy 7.1%. After adjusting for established risk factors (diabetes duration, A1C, systolic blood pressure, waist-to-hip ratio, and use of diabetes medications), fibrinogen (odds ratio 1.14 [95% CI 1.01-1.32], P = 0.05) and PAP (1.25 [1.05-1.50], P = 0.01) were associated with any diabetic retinopathy, while PAP (1.54 [1.13-2.11], P = 0.007) and homocysteine (1.57 [1.16-2.11], P = 0.003) were associated with vision-threatening diabetic retinopathy. Only PAP remained significant after additional adjustment for serum creatinine and UAC ratio. Area under receiver-operator characteristic curve (AUROC) for diabetic retinopathy was constructed for established and novel risk factors. Established risk factors accounted for a 39.2% increase of the AUROC, whereas novel markers (fibrinogen, PAP, homocysteine, serum creatinine, and UAC ratio) only accounted for an additional 2.2%. CONCLUSIONS: There were few associations of novel markers of inflammation, hemostasis, and homocysteine with diabetic retinopathy after controlling for established risk factors. These data suggest that there is limited clinical use of these biomarkers for prediction of diabetic retinopathy.

Is nuclear magnetic resonance lipoprotein subclass related to diabetic retinopathy? The multi-ethnic study of atherosclerosis (MESA).

OBJECTIVE: To examine the associations between nuclear magnetic resonance (NMR) defined lipoproteins and diabetic retinopathy (DR) in a population-based sample of adults with type 2 diabetes. RESEARCH DESIGN AND METHODS: In all, 921 persons with diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA) were included. DR was assessed from retinal photographs. Lipoproteins were measured by NMR spectroscopy. RESULTS: After controlling for age, race/ethnicity, study centre and diabetes and vascular risk factors, no consistent patterns of associations between NMR-defined lipoprotein particle concentrations and subclass with DR were evident. CONCLUSION: The lack of association between NMR-defined lipoproteins and DR does not support clinical use of NMR spectroscopy for management of patients with DR.

Analysis of rare variants in the complement component 2 (C2) and factor B (BF) genes refine association for age-related macular degeneration (AMD).

PURPOSE: Several single-nucleotide polymorphisms (SNPs) in the C2 and BF genes have been associated with age-related macular degeneration (AMD) in Caucasian populations from the United States. The study was conducted to evaluate whether these SNPs are also associated with AMD in persons of Anglo-Celtic ethnicity in an Australian population. METHODS: Included in the study were 565 persons with AMD and 204 ethnically matched control subjects. All participants completed a standard health questionnaire, were given a fundus examination, and provided a blood sample for DNA extraction. Alleles were determined by a matrix-assisted desorption ionization-time of flight (MALDI-TOF)-based approach followed by statistical analysis. RESULTS: The C2 and BF genes indicated significant association with AMD of only two SNPs; rs547154 (IVS10) in the C2 gene (P=9.1 x 10(-5)) and rs641153 (R32Q) in the BF gene (P=7.0 x 10(-5)). No association with AMD was found for SNP rs9332739 (E318D) in the C2 gene or for rs4151667 (L9H), rs1048709 (R150R), rs4151659 (K565E), or rs2072633 (IVS17) in the BF gene. A protective haplotype of variants IVS10 and R32Q was associated with AMD (OR 0.29, 95% CI 0.20-0.42). CONCLUSIONS: In this study, the association of the IVS10 and R32Q variants in the C2 and BF genes in AMD was replicated. Haplotype analysis indicated association of these variants with AMD in an Australian population. Both IVS10 and R32Q variants were in strong linkage disequilibrium with each other (r(2)=0.96). Although the E318D and L9H variants have shown association with AMD in previous studies, the findings were not in agreement. This demonstrates a refined pattern of association of these rare variants with AMD.

Prevalence and risk factors of retinal arteriolar emboli: the Singapore Malay Eye Study.

PURPOSE: To examine the prevalence and risk factors of retinal arteriolar emboli, a risk predictor of stroke, in an Asian population. DESIGN: Population-based cross-sectional study. METHODS: Retinal emboli were ascertained from retinal photographs obtained from both eyes of 3,265 Asian Malays, aged 40 to 80 years, according to a standardized protocol. Risk factors were assessed from detailed standardized interviews, clinical examinations, and laboratory investigations. RESULTS: The overall prevalence of retinal emboli was 0.6% (95% confidence interval [CI], 0.58 to 0.62). A finding of retinal emboli was strongly associated with increasing age (P = .005, for trend), but age-stratified prevalence rates were still lower than those reported from previous population-based studies of White persons. After adjusting for age and gender, the presence of retinal emboli was associated with cigarette smoking (odds ratio [OR], 5.96; 95% CI, 1.75 to 20.32), elevated total cholesterol (OR, 5.21; 95% CI, 1.93 to 12.82), low-density lipoprotein cholesterol (OR, 2.98; 95% CI, 1.20 to 7.39), and self-reported history of angina (OR, 5.67; 95% CI, 1.62 to 19.91). These associations remained significant in multivariate analysis with additional adjustment for other risk factors. CONCLUSIONS: Retinal emboli are less common in Asians than in similarly aged White persons, but are associated with similar cardiovascular risk factors.

Retinal vessel caliber and the long-term incidence of age-related cataract: the Blue Mountains Eye Study.

OBJECTIVE: To determine whether local nutritional or ischemic factors are involved in cataract pathogenesis, we aimed to assess whether narrowed retinal vessel caliber predicted the long-term incidence of age-related cataract, as shown in 1 previous report. DESIGN: Population-based cohort study. PARTICIPANTS: The Blue Mountains Eye Study examined 3654 baseline participants (1992-1994), 2335 (75.1% of survivors) after 5 years, and 1952 (75.6% of survivors) after 10 years. METHODS: Retinal vessel caliber was measured from baseline retinal photographs using computer-assisted techniques. Mean arteriolar and venular diameters of each eye were summarized as central retinal arterial (CRAE) and venular (CRVE) equivalents. Cataract was assessed from lens photographs of both eyes using the Wisconsin grading system. MAIN OUTCOME MEASURES: Nuclear cataract was defined as opacity > Wisconsin standard photograph 3, cortical cataract defined as opacity >or=5% of the lens area, and posterior subcapsular (PSC) cataract as any present. Eye-specific data were analyzed using generalized estimating equations. Odds ratios (OR) and 95% confidence intervals (CI) are reported. RESULTS: After adjusting for age, gender, smoking, hypertension, diabetes, body mass index, and inhaled steroid use, reduced incidence of nuclear cataract was associated with the narrowest compared with the widest quintile of CRAE and CRVE (for CRAE: OR, 0.62; 95% CI 0.42-0.92; for CRVE: OR, 0.70; 95% CI, 0.47-1.05) but a higher incidence of PSC cataract (for CRAE: OR, 2.40; 95% CI, 1.34-4.29; for CRVE: OR, 3.17; 95% CI, 1.62-6.20) and cataract surgery (for CRAE: OR, 1.52; 95% CI, 1.06-2.17; for CRVE: OR, 1.58; 95% CI, 1.08-2.32). These associations were not maintained when both CRAE and CRVE were included simultaneously in the same models. Path analysis suggested that age was the most important contributor to nuclear cataract incidence, and CRAE and CRVE, as markers of a latent age-related variable, were only indirectly associated with its incidence (for CRAE: OR, 0.61; 95% CI, 0.41-0.91; for CRVE: OR, 0.62; 95% CI, 0.41-0.94). CONCLUSIONS: Retinal vessel narrowing predicted greater risk of long-term incidence of PSC cataract and cataract surgery, and was indirectly linked to a lower incidence of nuclear cataract. Retinal vessel narrowing could be a marker of age-related factors associated with risk of PSC and nuclear cataract.

Functional presbyopia in a rural Kenyan population: the unmet presbyopic need.

BACKGROUND: Presbyopia is the most common reason for requiring spectacles in low-income regions, although the unmet need for presbyopic spectacles in these regions is very high. The aim of this study was to estimate the prevalence of presbyopia, and the functional impairment and spectacle use among persons with presbyopia in a rural Kenyan population. METHODS: A cross-sectional study was carried out in the Rift Valley, Kenya. Clusters were selected through probability-proportionate to size sampling, and people aged >/=50 years within the clusters were identified through compact segment sampling. Within the context of this survey, 130 eligible participants were selected for interview and underwent near-vision testing. Functional presbyopia was defined as requiring at least +1.00 dioptre in order to read the N8 optotype at a distance of 40 cm in the participant's usual visual state. Participants were corrected to the nearest 0.25 dioptre in order to see N8. Unmet and met presbyopic need, and presbyopic correction coverage were calculated. RESULTS: Functional presbyopia was found in 111 participants (85.4%). Mean age was lower in those with presbyopia (64.1 years vs. 71.5 years, P = 0.004). Increasing degree of addition required to see N8 was significantly associated with increased difficulty with reading (P = 0.04), sewing (P = 0.03), recognizing small objects (P = 0.02) and harvesting grains (P = 0.05). Among participants with functional presbyopia, 5.4% wore reading glasses and 25.2% had prior contact with an eye care professional. The unmet presbyopic need was 80.0%, met presbyopic need was 5.4% and presbyopic correction coverage was 6.3%. Cost was cited as the main barrier to spectacle use in 62% of participants with presbyopia. CONCLUSION: In low-income regions, there is a high prevalence of uncorrected presbyopia, which is associated with near-vision functional impairment. Provision of spectacles for near vision remains a priority in low-income regions.

Relationships of retinal vessel diameters with optic disc, macular and retinal nerve fiber layer parameters in 6-year-old children.

PURPOSE: To describe the normal anatomic relationships of retinal vessel diameters with optic disc, macula, and retinal nerve fiber layer parameters in young children. METHODS: This was a population-based, cross-sectional study of 1204 healthy children 6 years of age who were participating in the Sydney Childhood Eye Study. Retinal arteriolar and venular diameters were measured from fundus photographs using standardized computer-based methods. Optical coherence tomography was performed to obtain measurements of the optic disc, macula, and retinal nerve fiber layer parameters. RESULTS: In multivariate analyses, each standard deviation (SD) decrease in optic disc area was associated with a 0.14-pixel decrease (P = 0.05) in arteriolar diameter and a 0.31-pixel decrease (P < 0.01) in venular diameter. Each SD decrease in optic cup area was associated with a 0.15-pixel decrease (P = 0.05) in arteriolar diameter and a 0.43-pixel decrease (P < 0.01) in venular diameter. Each SD decrease in macular (inner/outer) thickness or volume was associated with a 0.25- to 0.39-pixel decrease (P < 0.01) in arteriolar diameter and a 0.36- to 0.71-pixel decrease (P < 0.01) in venular diameter, and each SD decrease in retinal nerve fiber layer thickness was associated with a 0.62-pixel decrease (P < 0.01) in arteriolar diameter and a 0.99-pixel decrease (P < 0.01) in venular diameter. CONCLUSIONS: Children's eyes with a smaller optic disc, thinner macula, and thinner retinal nerve fiber layer have narrower retinal vessels. These anatomic relationships may provide new insights into the vascular etiology of various ocular diseases.

Assessment of TGIF as a candidate gene for myopia.

PURPOSE: Transforming growth beta-induced factor (TGIF) has been identified as a candidate gene for high myopia through genetic linkage studies and through its role in ocular growth in animal studies. However, the association of single nucleotide polymorphisms (SNPs), based solely on myopia refraction, has so far been inconclusive. This is the first study conducted to investigate the association of TGIF with refraction and ocular biometric measurements. METHODS: Twelve tag SNPs (tSNPs) encompassing the TGIF gene and 2 kb upstream of its promoter region were used to evaluate the association between TGIF variants with both ocular biometric measures and refraction. A total of 257 cases of myopia (spherical equivalent [SE] worse than -0.50 D) and 294 control subjects (no myopia) were genotyped. Genotype frequencies were analyzed by chi(2) test and one-way ANOVA. RESULTS: Two tSNPs showed significant association with biometric measures, with the SNP rs8082866 being associated with both axial length (P = 0.013) and corneal curvature (P = 0.007) and the SNP rs2020436 being associated with corneal curvature (P = 0.022). However, these associations became nonsignificant after multiple testing (Bonferroni correction). CONCLUSIONS: Findings of this study suggest that the TGIF gene is unlikely to play a major role in either ocular biometric measures or refraction in a Caucasian population. Future studies should focus on other genes in the MYP2 linkage region or other linked regions to identify myopia-causing genes.

Retinal arteriolar narrowing predicts incidence of diabetes: the Australian Diabetes, Obesity and Lifestyle (AusDiab) Study.

OBJECTIVE: To examine the relationship of retinal vascular caliber to incident diabetes in a population-based cohort. RESEARCH DESIGN AND METHODS: The Australian Diabetes, Obesity and Lifestyle (AusDiab) Study recruited adults aged 25+ years across Australia in 1999-2000, with a follow-up 5 years later in 2004-2005. Participants' glycemic status was classified using fasting plasma glucose (FPG) and 2-h oral glucose tolerance (2-h plasma glucose [2hPG]) tests. Diabetes was diagnosed if FPG was >or=7.0 mmol/l or 2hPG was >or=11.1 mmol/l. Retinal vascular caliber was measured from baseline retinal photographs using a computer-assisted program. RESULTS: Of the 803 participants without diabetes at baseline, 108 (13.4%) developed diabetes at follow-up: 7 (2.8%) of 246 participants with normal glucose tolerance, 9 (13.6%) of 66 participants with impaired fasting glucose, and 92 (18.7%) of 491 participants with impaired glucose tolerance. After multivariate analysis, participants with narrower retinal arteriolar caliber had a higher risk of diabetes (odds ratio 2.21 [95% CI 1.02-4.80], comparing smallest versus highest arteriolar caliber tertiles, P = 0.04 for trend). There was no association between retinal venular caliber and incident diabetes. CONCLUSIONS: Narrower retinal arteriolar caliber predicted risk of diabetes. These data provide further evidence that microvascular changes may contribute to the pathogenesis of diabetes.