Prediction of incident stroke events based on retinal vessel caliber: a systematic review and individual-participant meta-analysis

The caliber of the retinal vessels has been shown to be associated with stroke events. However, the consistency and magnitude of association, and the changes in predicted risk independent of traditional risk factors, are unclear. To determine the association between retinal vessel caliber and the risk of stroke events, the investigators combined individual data from 20,798 people, who were free of stroke at baseline, in 6 cohort studies identified from a search of the Medline (National Library of Medicine, Bethesda, Maryland) and EMBASE (Elsevier B.V., Amsterdam, the Netherlands) databases. During follow-up of 5-12 years, 945 (4.5%) incident stroke events were recorded. Wider retinal venular caliber predicted stroke (pooled hazard ratio = 1.15, 95% confidence interval: 1.05, 1.25 per 20-micron increase in caliber), but the caliber of retinal arterioles was not associated with stroke (pooled hazard ratio = 1.00, 95% confidence interval: 0.92, 1.08). There was weak evidence of heterogeneity in the hazard ratio for retinal venular caliber, which may be attributable to differences in follow-up strategies across studies. Inclusion of retinal venular caliber in prediction models containing traditional stroke risk factors reassigned 10.1% of people at intermediate risk into different, mostly lower, risk categories.

Heterozygous NTF4 mutations impairing neurotrophin-4 signaling in patients with primary open-angle glaucoma

Glaucoma, a main cause of blindness in the developed world, is characterized by progressive degeneration of retinal ganglion cells (RGCs), resulting in irreversible loss of vision. Although members of the neurotrophin gene family in various species are known to support the survival of numerous neuronal populations, including RGCs, it is less clear whether they are also required for survival and maintenance of adult neurons in humans. Here, we report seven different heterozygous mutations in the Neurotrophin-4 (NTF4) gene accounting for about 1.7% of primary open-angle glaucoma patients of European origin. Molecular modeling predicted a decreased affinity of neurotrophin 4 protein (NT-4) mutants with its specific tyrosine kinase receptor B (TrkB). Expression of recombinant NT-4 carrying the most frequent mutation was demonstrated to lead to decreased activation of TrkB. These findings suggest a pathway in the pathophysiology of glaucoma through loss of neurotrophic function and may eventually open the possibility of using ligands activating TrkB to prevent the progression of the disease.

Effects of blood pressure lowering and intensive glucose control on the incidence and progression of retinopathy in patients with type 2 diabetes mellitus: a randomised controlled trial

AIMS/HYPOTHESIS

The aim of the present study was to investigate the effect of blood pressure lowering and intensive glucose control on the incidence and progression of retinopathy in type 2 diabetic patients.

METHODS

The Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) Retinal Measurements study, a substudy of ADVANCE, is a randomised (using a central, computer-based procedure) controlled 2 x 2 factorial trial comprising a double-blind comparison of blood pressure lowering with perindopril-indapamide vs placebo, and an open comparison of standard vs intensive glucose control targeting a HbA(1c) of < or = 6.5% in 1,602 diabetic patients from ADVANCE centres with access to retinal cameras conducted from 2001 to 2008. At baseline and the final visit, seven-field stereoscopic retinal photographs were taken and graded by blinded readers (gradeable baseline and final photographs from 1,241 patients). Progression of > or =2 steps in the Early Treatment of Diabetic Retinopathy Study classification (using the eye with worst grading) was the primary outcome.

RESULTS

Retinopathy progressed in 59 (4.8%) patients and developed in 128 (10.3%) patients over 4.1 years. Fewer patients on blood pressure-lowering treatment (n = 623) experienced incidence or progression of retinopathy compared with patients on placebo (n = 618), but the difference was not significant (OR 0.78; 95% CI 0.57-1.06; p = 0.12). Blood pressure-lowering treatment reduced the occurrence of macular oedema (OR 0.50; 95% CI 0.29-0.88; p = 0.016) and arteriovenous nicking compared with placebo (OR 0.60; 95% CI 0.38-0.94; p = 0.025). Compared with standard glucose control (n = 611), intensive glucose control (n = 630) did not reduce (p = 0.27) the incidence and progression of retinopathy (OR 0.84; 95% CI 0.61-1.15). Lower, borderline significant risks of microaneurysms, hard exudates and macular oedema were observed with intensive glucose control, adjusted for baseline retinal haemorrhages. These effects of the two treatments were independent and additive. Adverse events in the ADVANCE study are reported elsewhere.

CONCLUSIONS/INTERPRETATION

Blood pressure lowering or intensive glucose control did not significantly reduce the incidence and progression of retinopathy, although consistent trends towards a benefit were observed, with significant reductions in some lesions observed with both interventions.

TRIAL REGISTRATION

ClinicalTrials.gov ID no. NCT00145925.

FUNDING

Grants from Servier and the National Health and Medical Research Council of Australia.

Meta-analysis: retinal vessel caliber and risk for coronary heart disease

BACKGROUND

Retinal vessel caliber may be a novel marker of coronary heart disease (CHD) risk. However, the sex-specific effect, magnitude of association, and effect independent of traditional CHD disease risk factors remain unclear.

PURPOSE

To determine the association between retinal vessel caliber and risk for CHD.

DATA SOURCES

Relevant studies in any language identified through MEDLINE (1950 to June 2009) and EMBASE (1950 to June 2009) databases.

STUDY SELECTION

Studies were included if they examined a general population, measured retinal vessel caliber from retinal photographs, and documented CHD risk factors and incident CHD events.

DATA EXTRACTION

6 population-based prospective cohort studies provided data for individual participant meta-analysis.

DATA SYNTHESIS

Proportional hazards models, adjusted for traditional CHD risk factors, were constructed for retinal vessel caliber and incident CHD in women and men. Among 22,159 participants who were free of CHD and followed for 5 to 14 years, 2219 (10.0%) incident CHD events occurred. Retinal vessel caliber changes (wider venules and narrower arterioles) were each associated with an increased risk for CHD in women (pooled multivariable-adjusted hazard ratios, 1.16 [95% CI, 1.06 to 1.26] per 20-microm increase in venular caliber and 1.17 [CI, 1.07 to 1.28] per 20-microm decrease in arteriolar caliber) but not in men (1.02 [CI, 0.94 to 1.10] per 20-microm increase in venular caliber and 1.02 [CI, 0.95 to 1.10] per 20-microm decrease in arteriolar caliber). Women without hypertension or diabetes had higher hazard ratios.

LIMITATION

Error in the measurement of retinal vessel caliber and Framingham variables was not taken into account.

CONCLUSION

Retinal vessel caliber changes were independently associated with an increased risk for CHD events in women.

Association of diabetes with age-related macular degeneration in the EUREYE study

OBJECTIVE

To examine the association between self-reported diabetes history and early or late age-related macular degeneration (AMD) in the European population.

METHODS

Participants aged 65 years and over in the cross-sectional population-based EUREYE study underwent an eye examination including digital retinal photography. The images were graded at a single centre. A structured questionnaire was administered by trained field workers for putative risk factors for AMD including history of diabetes mellitus. Logistic regression models were used to examine the association between diabetes and stages of AMD, taking account of potential demographic, behavioural, dietary and medical (history of cardiovascular disease) confounders.

MAIN OUTCOME MEASURES

Photographic images were graded according to the modified International Classification System for AMD and stratified into five exclusive stages from no signs of AMD (AMD stage 0), early AMD (Stages 1-3) and late AMD (Stage 4). Late AMD was subdivided in neovascular AMD (NV-AMD) or geographic atrophy (GA).

RESULTS

Data on diabetes history and potential confounders were available in 2117 control subjects without AMD, 2182 with early AMD, 49 with GA and 101 with NV-AMD. Of all participants, 13.1% reported a history of diabetes. After adjusting for potential confounders, subjects with neovascular AMD compared with controls had increased odds for diabetes (odds ratio 1.81; 95% confidence interval, 1.10 to 2.98, p = 0.02). Subjects with AMD grades 1 to 3 or GA had no increased odds for diabetes compared with those without AMD.

CONCLUSIONS

In the EUREYE study, after multiple adjustments, positive association of diabetes mellitus with neovascular AMD was found. The hypothesis that diabetes is associated with neovascular AMD but not with geographic atrophy may suggest a different pathogenesis of the two advanced forms of the disease and needs to be further evaluated.

The Rotterdam Study: 2010 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in close to a 1,000 research articles and reports (see www.epib.nl/rotterdamstudy). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Sunlight exposure, antioxidants, and age-related macular degeneration

OBJECTIVE

To examine the association of sunlight exposure and antioxidant level with age-related macular degeneration (AMD).

METHODS

Four thousand seven hundred fifty-three participants aged 65 years or older in the European Eye Study underwent fundus photography, were interviewed for adult lifetime sunlight exposure, and gave blood for antioxidant analysis. Blue light exposure was estimated by combining meteorologic and questionnaire data.

RESULTS

Data on sunlight exposure and antioxidants were available in 101 individuals with neovascular AMD, 2182 with early AMD, and 2117 controls. No association was found between blue light exposure and neovascular or early AMD. Significant associations were found between blue light exposure and neovascular AMD in individuals in the quartile of lowest antioxidant level-vitamin C, zeaxanthin, vitamin E, and dietary zinc-with an odds ratio of about 1.4 for 1 standard deviation unit increase in blue light exposure. Higher odds ratios for blue light were observed with combined low antioxidant levels, especially vitamin C, zeaxanthin, and vitamin E (odds ratio, 3.7; 95% confidence interval, 1.6-8.9), which were also associated with early stages of AMD.

CONCLUSIONS

Although it is not possible to establish causality between sunlight exposure and neovascular AMD, our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients.

Oily fish consumption, dietary docosahexaenoic acid and eicosapentaenoic acid intakes, and associations with neovascular age-related macular degeneration

BACKGROUND

Fish intake, the major source of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may reduce the risk of age-related macular degeneration (AMD).

OBJECTIVE

We investigated the association of oily fish and dietary DHA and EPA with neovascular AMD (NV-AMD).

DESIGN

Participants aged >/=65 y in the cross-sectional population-based EUREYE study underwent fundus photography and were interviewed by using a food-frequency questionnaire. Fundus images were graded by the International Classification System for Age Related Maculopathy. Questionnaire data were converted to nutrient intakes with the use of food-composition tables. Survey logistic regression was used to calculate odds ratios (ORs) and 95% CIs of energy-adjusted quartiles of EPA or DHA with NV-AMD, taking into account potential confounders.

RESULTS

Dietary intake data and fundus images were available for 105 cases with NV-AMD and for 2170 controls without any features of early or late AMD. Eating oily fish at least once per week compared with less than once per week was associated with a halving of the odds of NV-AMD (OR = 0.47; 95% CI: 0.33, 0.68; P = 0.002). Compared with the lowest quartile, there was a significant trend for decreased odds with increasing quartiles of either DHA or EPA. ORs in the highest quartiles were 0.32 (95% CI: 0.12, 0.87; P = 0.03) for DHA and 0.29 (95% CI: 0.11, 0.73; P = 0.02) for EPA.

CONCLUSIONS

Eating oily fish at least once per week compared with less than once per week was associated with a halving of the OR for NV-AMD.

Alcohol consumption and risk of aging macula disorder in a general population: the Rotterdam Study

OBJECTIVE

To investigate the possible relationship between overall or specific alcohol consumption and risk of aging macula disorder (AMD), a synonym for age-related macular degeneration, in a general population.

METHODS

Alcohol consumption and risk of early or late incident AMD (iAMD) were examined among all participants in the prospective population-based Rotterdam Study, with complete data on alcohol consumption among 4229 subjects at risk of AMD. Aging macula disorder was graded according to the International Classification and Grading System for AMD by 2 trained professionals who were masked for all other determinants. We used Cox proportional hazards regression models to estimate hazard ratios and corresponding 95% confidence intervals.

RESULTS

During a mean follow-up period of 8.0 years, 600 cases of iAMD were identified, of which 519 were early iAMD and 81 were late iAMD. After correction for age, sex, smoking, complement factor H genotype status, and other potential confounders, we did not find an association between overall or specific alcohol consumption and development of early iAMD or dry or wet late iAMD.

CONCLUSION

Our findings suggest that overall or specific alcohol consumption is not a risk factor for AMD.

Cataract surgery and the risk of aging macula disorder: the rotterdam study

PURPOSE

To investigate still-controversial associations between prior cataract surgery and aging macula disorder (AMD) in a general population.

METHODS

Baseline lens status and risk of incident AMD (iAMD) were examined in participants of the prospective population-based Rotterdam Study at risk for AMD (n = 6032). Slit lamp examination was used to determine lens status and stereoscopic color fundus photography to determine the presence of AMD. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated with generalized estimating equation (GEE) models. Stratified analyses were also performed for CFH Y402H genotype.

RESULTS

After adjusting for age, sex, follow-up time, and the correlation between eyes, a history of cataract surgery was associated with incident dry late AMD (OR, 3.43; 95% CI, 1.82-6.49). This association remained significant after additional adjustment for smoking status and AMD stage at baseline (OR, 3.44; 95% CI, 1.68-7.08). No statistically significant association was found between prior cataract surgery and the incidence of wet late AMD or early AMD. Homozygous CFH Y402H carriers had higher risks for all types of AMD compared to heterozygotes and noncarriers after cataract surgery, particularly for dry AMD.

CONCLUSIONS

The findings imply that cataract surgery increases the risk of dry AMD, particularly in homozygous CFH Y402H carriers. The risk of AMD progression should be considered before recommending cataract surgery to patients with cataract and early AMD.

Retinal vascular lesions in patients of Caucasian and Asian origin with type 2 diabetes: baseline results from the ADVANCE Retinal Measurements (AdRem) study

OBJECTIVE

The objective of this study was to describe prevalent vascular retinal lesions among patients with type 2 diabetes enrolled in the ADVANCE Retinal Measurements (AdRem) study, a substudy of the Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) trial.

RESEARCH DESIGN AND METHODS

Seven-field stereoscopic photographs of both eyes were obtained at the baseline assessment of the ADVANCE trial. All photographs were graded in a central reading center. Gradable retinal images were received from 1,605 patients.

RESULTS

The number of patients with any retinopathy (Early Treatment of Diabetic Retinopathy Study [ETDRS] score > or = 20) was 645 (40.2% [95% CI 37.8-42.6]); of these, 35 (2.2% [1.6-3.0]) had severe diabetic retinopathy (ETDRS score > or = 50). Focal arterial narrowing, venous beading, and arteriovenous nicking were present in 3.8, 5.1, and 9.8% of participants, respectively. Among participants included in this study, Chinese and South-Asian patients had more retinopathy than Caucasians, as defined both by ETDRS score (49.4, 46.0, and 31.3%, respectively; P < 0.001, adjusted for age, sex, A1C, systolic blood pressure, and duration of diabetes) and specific vascular lesions (e.g., arteriovenous nicking 12.3, 8.5, and 7.5%, respectively; adjusted P < 0.005). A1C, duration of diabetes, and systolic blood pressure were similarly associated with increased retinal lesions in Chinese, South-Asian, and Caucasian patients.

CONCLUSIONS

Using a sensitive diagnostic procedure, more than one-third of patients with type 2 diabetes enrolled in the AdRem study had retinal lesions at baseline. Despite differences in prevalence and severity of retinopathy among Chinese, South-Asian, and Caucasian patients included in this study, the cross-sectional associations among established risk factors for retinopathy and retinal lesions were similar across ethnic groups.

Three genome-wide association studies and a linkage analysis identify HERC2 as a human iris color gene

Human iris color was one of the first traits for which Mendelian segregation was established. To date, the genetics of iris color is still not fully understood and is of interest, particularly in view of forensic applications. In three independent genome-wide association (GWA) studies of a total of 1406 persons and a genome-wide linkage study of 1292 relatives, all from the Netherlands, we found that the 15q13.1 region is the predominant region involved in human iris color. There were no other regions showing consistent genome-wide evidence for association and linkage to iris color. Single nucleotide polymorphisms (SNPs) in the HERC2 gene and, to a lesser extent, in the neighboring OCA2 gene were independently associated to iris color variation. OCA2 has been implicated in iris color previously. A replication study within two populations confirmed that the HERC2 gene is a new and significant determinant of human iris color variation, in addition to OCA2. Furthermore, HERC2 rs916977 showed a clinal allele distribution across 23 European populations, which was significantly correlated to iris color variation. We suggest that genetic variants regulating expression of the OCA2 gene exist in the HERC2 gene or, alternatively, within the 11.7 kb of sequence between OCA2 and HERC2, and that most iris color variation in Europeans is explained by those two genes. Testing markers in the HERC2-OCA2 region may be useful in forensic applications to predict eye color phenotypes of unknown persons of European genetic origin.

Risk of bilateral visual impairment in individuals with amblyopia: the Rotterdam study

BACKGROUND

The excess risk of bilateral visual impairment (BVI; bilateral visual acuity <0.5) among individuals with amblyopia is an argument for screening for amblyopia, but data are scarce.

METHODS

The risk was estimated by determining the incidence of BVI in the Rotterdam Study, a population-based cohort of subjects aged 55 years or over (n = 5220), including 192 individuals with amblyopia (3.7%). Using a multistate lifetable, the lifetime risk and excess period spent with BVI were determined.

RESULTS

The relative risk of BVI for amblyopes was 2.6 (95% confidence interval 1.4-4.5). For individuals with amblyopia, the lifetime risk of BVI was 18%, whereas they lived on average 7.2 years with BVI. For non-amblyopic individuals, these figures were 10% and 6.7 years, respectively.

CONCLUSION

Amblyopia nearly doubles the lifetime risk of BVI and affected individuals spent an extra six months with BVI. This study provides data for future cost-effectiveness analyses.

C-reactive protein level and risk of aging macula disorder: The Rotterdam Study

OBJECTIVE

To examine whether C-reactive protein (CRP) level is a risk factor for aging macula disorder (AMD) in a general population.

METHODS

We examined serum high-sensitivity CRP (HsCRP) levels in 4914 participants of the population-based Rotterdam Study at risk for AMD. After a mean follow-up of 7.7 years, 561 cases of early and 97 cases of late incident AMD (iAMD) were identified. We used Cox proportional hazards regression models to estimate hazard ratios and corresponding 95% confidence intervals (CIs).

RESULTS

After adjustment for age and sex, hazard ratios were 1.11 (95% CI, 1.02-1.21) per standard deviation increase in HsCRP level for early iAMD and 1.28 (95% CI, 1.02-1.60) for late iAMD. Hazard ratios for early iAMD increased per quartile increase in HsCRP level as follows: second quartile, 1.19 (95% CI, 0.94-1.52); third quartile, 1.29 (95% CI, 1.01-1.64); and fourth quartile, 1.33 (95% CI, 1.05-1.70). The risk of late iAMD was higher in all upper quartiles of HsCRP.

CONCLUSION

Elevated baseline levels of HsCRP were associated with the development of early and late AMD in this large population-based cohort.

The Rotterdam Study: objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in the Netherlands. The study targets cardiovascular, neurological, ophthalmological and endocrine diseases. As of 2008 about 15,000 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in some 600 research articles and reports (see http://www.epib.nl/rotterdamstudy). This article gives the reasons for the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Genetic Contributions to Glaucoma: Heritability of Intraocular Pressure, Retinal Nerve Fiber Layer Thickness, and Optic Disc Morphology

PURPOSE

The genetic etiology of primary open-angle glaucoma (POAG) is still largely unknown, because of its complexity and disparities in its classification. This study was undertaken to determine the genetic contribution to various early, continuous markers of POAG by assessing the heritability of intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, and neuroretinal rim and optic disc parameters in a genetically isolated population.

METHODS

A total of 2620 subjects (mean age, 48 years; range 18-86) from extended pedigrees living in a small town in The Netherlands underwent an extensive ophthalmic examination. Their IOP was measured by Goldmann applanation tonometry, their RNFL thickness by scanning laser polarimetry (GDx VCC), and their optic disc parameters by confocal scanning laser ophthalmoscopy (HRT II). Risk associations were explored by linear regression analyses and heritability estimates by variance component methods.

RESULTS

Inbreeding was present in 2042 (81%) participants, and was significantly associated with a higher IOP (P < 0.001). The heritability estimate for IOP was 0.35 (95% confidence interval [CI], 0.27-0.43); for RNFL thickness, 0.48 (95% CI, 0.35-0.60); and for neuroretinal rim area, 0.39 (95% CI, 0.20-0.58). Nongenetic factors accounted for only a small proportion (<or=0.13) of the variance in all three traits.

CONCLUSIONS

Early, continuous markers of POAG are strongly determined by additive genetic effects. The results support a quantitative trait linkage strategy to discover new genes for POAG.

Blood pressure, arterial stiffness, and open-angle glaucoma: the Rotterdam study

OBJECTIVE

To investigate cross-sectional associations among blood pressures (BPs), arterial stiffness, and open-angle glaucoma (OAG).

METHODS

Study participants came from the population-based Rotterdam Study. The baseline examination phase took place after an extensive home interview from March 20, 1990, to June 17, 1993, and the third phase between March 19, 1997, and December 16, 1999. Cases were classified into high-tension OAG (htOAG) and normal-tension OAG (ntOAG), according to an intraocular pressure greater than 21 mm Hg or 21 mm Hg or less. Pulse pressure was the difference between systolic and diastolic BP. Diastolic perfusion pressure was the difference between diastolic BP and the intraocular pressure; indicators of arterial stiffness were carotid-femoral pulse wave velocity and carotid distensibility. Associations were evaluated with logistic regression analysis, adjusted for age, sex, body mass index, smoking, diabetes mellitus, serum cholesterol level, and BP-lowering treatment.

RESULTS

A total of 5317 participants were included in this study. In participants with a higher pulse pressure, the prevalence of htOAG was elevated (odds ratio [OR] per standard deviation, 1.32; 95% confidence interval [CI], 1.03-1.69). In persons treated for systemic hypertension, low diastolic perfusion pressure (<50 mm Hg) was inversely associated with ntOAG (OR, 0.25; 95% CI, 0.10-0.63) and positively associated with htOAG (OR, 4.68; 95% CI, 1.29-17.01). The lowest tertile of carotid distensibility compared with the highest had an OR for htOAG of 2.84 (95% CI, 0.99-8.10; P=.05).

CONCLUSIONS

We found that htOAG was associated with high pulse pressure, possibly with increased carotid arterial stiffness, and, only in persons treated for systemic hypertension, with low diastolic perfusion pressure. In these persons, ntOAG was associated with high diastolic BP, whereas the association between ntOAG and low diastolic perfusion pressure was inverted.

Estrogen receptor alpha gene polymorphisms associated with incident aging macula disorder

PURPOSE

It has been suggested that early menopause increases the risk of aging-macula disorder (AMD), the major cause of incurable blindness with a dry and wet late subtype, and that exposure to endogenous or postmenopausal exogenous estrogens reduces this risk. This study was undertaken to investigate whether genetic variations in the estrogen receptor alpha (ESR1) gene are associated with incident AMD.

METHODS

In the Rotterdam Study, a prospective population-based cohort study of participants aged 55 years and older, associations between ESR1 PvuII-XbaI haplotypes and incident early or late AMD were studied in 4571 participants after a mean follow-up time of 7.7 years. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs), with adjustment for the most common confounders.

RESULTS

ESR1 PvuII-XbaI haplotype 1 was a risk factor for late AMD. Persons with two copies of haplotype 1 were at 3.20 (95% CI, 1.47-6.99) times higher risk for late AMD than noncarriers of haplotype 1, after adjustment for age and sex. This increase was more pronounced for wet AMD (hazard ratio [HR] 4.29; 95% CI, 1.47-12.49) after adjustment for age, sex, smoking, and complement factor H genotype. Correction for additional confounders, including age at menopause, use of hormone replacement therapy, blood pressure, and body mass index did not essentially alter the findings.

CONCLUSIONS

Persons with one or two copies of ESR1 PvuII-XbaI haplotype 1 have an increased risk of late AMD, especially of the wet form.

Cigarette smoking and age-related macular degeneration in the EUREYE Study

OBJECTIVE

To examine the association between cigarette smoking and age-related maculopathy (ARM) including age-related macular degeneration (AMD) in the European population.

DESIGN

Cross-sectional study.

PARTICIPANTS

Four thousand seven hundred fifty randomly sampled > or =65-year-olds from 7 study centers across Europe (Norway, Estonia, United Kingdom, France, Italy, Greece, and Spain).

METHODS

Participants underwent an eye examination and digital retinal photography. The images were graded at a single center. Smoking history was ascertained by a structured questionnaire administered by trained fieldworkers. Multinomial and binary logistic regressions were used to examine the association between smoking history and ARM grade and type of AMD, taking account of potential confounders and the multicenter study design.

MAIN OUTCOME MEASURES

Photographic images were graded according to the International Classification System for ARM and stratified using the Rotterdam staging system into 5 exclusive stages (ARM 0-3 and ARM 4, also known as AMD). Age-related macular degeneration also was classified as neovascular AMD or geographic atrophy (GA).

RESULTS

One hundred fifty-eight cases were categorized as AMD (109 neovascular AMD and 49 GA); 2260 had no signs of ARM (ARM 0). Current smokers had increased odds of neovascular AMD (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.4-4.8) or GA (OR, 4.8; 95% CI, 2.1-11.1), whereas for ex-smokers the odds were around 1.7. Compared with people with unilateral AMD, those with bilateral AMD were more likely to have a history of heavy smoking in the previous 25 years (OR, 5.1; 95% CI, 1.3-20.0). The attributable fraction for AMD due to smoking was 27% (95% CI, 19%-33%). There was no consistent association with ARM grades 1 to 3 and smoking.

CONCLUSIONS

These findings highlight the need for increasing public awareness of the risks associated with smoking and the benefit of quitting smoking. Patients with unilateral disease who are current smokers should be advised of the risk of second-eye disease.

Rationale and design of the AdRem study: Evaluating the effects of blood pressure lowering and intensive glucose control on vascular retinal disorders in patients with type 2 diabetes mellitus

The ADVANCE Retinal Measurements (AdRem) Study is a large intervention study evaluating the effects of target driven intensive glucose control and placebo controlled blood pressure lowering on retinal vascular changes. AdRem is a sub-study of the ADVANCE Study (Action in Diabetes and Vascular disease), a 2x2 factorial randomized controlled trial with an ACE inhibitor-diuretic combination (perindopril-indapamide) and a gliclazide MR-based regimen in patients with type 2 diabetes mellitus. The AdRem study is based on seven-field stereoscopic retinal photographs of both eyes. These are taken within 3 months after randomization in ADVANCE (baseline), at the biennial and at the final visit. The primary outcome is progression of two or more steps in ETDRS classification. Secondary outcomes include progression of retinal vascular lesions and distortion of retinal vascular geometry. Retinal photographs are made on film and digitized at a central laboratory. The AdRem study uses fully digitized quality control and grading. Between August 2002 and January 2004 1978 patients were included in the AdRem study, from 39 centers in 14 countries. Approximately 85% comply with the strict AdRem quality requirements. Publication of the results is expected in early 2008. The AdRem study is designed to provide reliable evidence on the effects of intensive glucose control and blood pressure lowering on both diabetic retinopathy and abnormalities of retinal vasculature in patients with type 2 diabetes mellitus.

An igf-I gene polymorphism modifies the risk of diabetic retinopathy

The role of IGF-I in the pathogenesis of diabetic retinopathy is unclear. We studied, prospectively, the relationship between an IGF-I gene polymorphism, retinal vessel diameters, and incident diabetic retinopathy in subjects with impaired glucose tolerance (IGT) or type 2 diabetes. In all 5,505 participants of the population-based Rotterdam Study (775 with IGT, 394 with type 2 diabetes, and 4,336 control subjects), fundus color transparencies were taken at baseline (between 1990 and 1993) and at follow-up (from 1997 to 1999). The wild-type genotype (i.e., carriers of the 192- or 194-bp alleles) was present in 72.7% of the participants, while 27.3% were variant carriers. Variant carriers with IGT or type 2 diabetes appeared to have larger retinal arteriolar and venular diameters at baseline than individuals with the wild-type genotype, but these differences did not reach statistical significance. This trend was especially observed in subjects who developed retinopathy at follow-up. In variant carriers with IGT/diabetes, an increase (odds ratio 1.8 [95% CI 1.0-3.2]; P = 0.04) in the risk of retinopathy was observed compared with participants with the wild-type genotype. In conclusion, our findings suggest that this IGF-I gene polymorphism is associated with an increased risk of diabetic retinopathy.

Complement factor H polymorphism, complement activators, and risk of age-related macular degeneration

CONTEXT

The evidence that inflammation is an important pathway in age-related macular degeneration (AMD) is growing. Recent case-control studies demonstrated an association between the complement factor H (CFH) gene, a regulator of complement, and AMD.

OBJECTIVES

To assess the associations between the CFH gene and AMD in the general population and to investigate the modifying effect of smoking, serum inflammatory markers, and genetic variation of C-reactive protein (CRP).

DESIGN, SETTING, AND PARTICIPANTS

Population-based, prospective cohort study of individuals aged 55 years or older (enrollment between March 20, 1990, and July 31, 1993, and 3 follow-up examinations that were performed between September 1, 1993, and December 31, 2004) in Rotterdam, the Netherlands. The CFH Y402H polymorphism was determined in a total of 5681 individuals. Information on smoking, erythrocyte sedimentation rate, CRP serum levels, and haplotypes of the CRP gene were assessed at baseline.

MAIN OUTCOME MEASURES

All severity stages of prevalent and incident AMD, graded according to the international classification and grading system for AMD.

RESULTS

The frequency of CFH Y402H was 36.2% (4116/11,362 alleles). At baseline, there were 2062 persons (36.3%) with any type of AMD (prevalent cases), including 78 (1.4%) with late AMD (stage 4). During follow-up (mean, 8 years; median, 10 years), 1649 (35.5%) of 4642 participants progressed to a higher stage of AMD (incident cases), including 93 (5.6%) who developed late AMD. The odds ratio (OR) of AMD increased in an allele-dose manner with 2.00 (95% confidence interval [CI], 1.56-2.55) for stage 2 AMD, 4.58 (95% CI, 2.82-7.44) for stage 3 AMD, and 11.02 (95% CI, 6.82-11.81) for stage 4 (late, vision threatening) AMD for homozygous persons. Cumulative risks calculated by Kaplan-Meier analysis of late AMD by age 95 years were 48.3% for homozygotes, 42.6% for heterozygotes, and 21.9% for noncarriers. The population-attributable risk for CFH Y402H was 54.0%. Elevated erythrocyte sedimentation rates further increased the OR to 20.2 (95% CI, 9.5-43.0), elevated serum CRP levels to 27.7 (95% CI, 10.7-72.0), and smoking to 34.0 (95% CI, 13.0-88.6) for homozygotes compared with noncarriers without these determinants. The CRP haplotypes conferring high levels of CRP significantly increased the effect of CFH Y402H (P<.01).

CONCLUSIONS

The CFH Y402H polymorphism may account for a substantial proportion of AMD in individuals similar to those in the Rotterdam Study and may confer particular risk in the presence of environmental and genetic stimulators of the complement cascade.

Retinal vessel diameters and risk of stroke: The Rotterdam Study

BACKGROUND

Retinal vessels may provide information on cerebral vascular pathology, because they share many features with cerebral vessels. A smaller ratio of the retinal arteriolar-to-venular diameters reportedly predicts the risk of stroke. It is unclear if this is due to arteriolar narrowing or venular dilation.

OBJECTIVE

To investigate whether smaller arteriolar or larger venular diameters are related to the risk of stroke and cerebral infarction.

METHODS

This study was based on the prospective population-based Rotterdam Study and included 5,540 participants of 55 years or over, who had gradable fundus transparencies and were free of stroke at baseline (1990 to 1993). For each participant, retinal arteriolar and venular diameters were measured on digitized images of one eye. Follow-up for first-ever stroke was complete until January 1, 2002.

RESULTS

After a mean follow-up of 8.5 years, 411 participants had a stroke, of whom 259 had cerebral infarction. Larger venular diameters were associated with an increased risk of stroke (hazard ratio [HR] adjusted for age and sex per SD increase: 1.12 [95% CI: 1.02 to 1.24]) and cerebral infarction (HR: 1.15 [95% CI: 1.02 to 1.29]). Smaller arteriolar diameters were neither related to the risk of stroke (HR per SD decrease: 1.02 [95% CI: 0.93 to 1.13]) nor to the risk of cerebral infarction (HR: 1.02 [95% CI: 0.90 to 1.15]). After additional adjustment for other cardiovascular risk factors, the results did not change.

CONCLUSIONS

Larger retinal venular diameters are associated with an increased risk of stroke and cerebral infarction. The role of venules in cerebrovascular disease warrants further exploration.

Prevalence of age-related maculopathy in older Europeans: the European Eye Study (EUREYE)

OBJECTIVE

To estimate the prevalence of age-related maculopathy in an older population from 7 European countries.

METHODS

Randomly sampled people 65 years and older were invited to an eye examination in centers across 7 European countries (Norway, Estonia, United Kingdom, France, Italy, Greece, and Spain). Fundus images of each eye were graded at a single reading center. Prevalence rates were calculated for stage of age-related maculopathy with 95% confidence intervals (CIs) estimated for clustered data.

RESULTS

Of 5040 participants (45% response rate), 4753 (2128 men and 2625 women) had gradable fundus images. The prevalences were grade 0, 47.59% (95% CI, 43.53%-51.65%); grade 1, 36.48% (95% CI, 32.66%-40.30%); grade 2, 10.14% (95% CI, 8.92% to 11.37%); grade 3, 2.46% (95% CI, 1.79%-3.13%); and grade 4 (age-related macular degeneration [AMD]), 3.32% (95% CI, 2.52%-4.13%) and large drusen only (> or = 125 microm), 15.41% (95% CI, 13.61%-17.21%). The prevalence of geographic atrophic AMD was 1.2% (95% CI, 0.8%-1.7%) and of neovascular AMD, 2.3% (95% CI, 1.7%-2.9%). The prevalence of bilateral AMD was 1.4% (95% CI, 1.0%-1.8%).

CONCLUSION

Age-specific prevalences of age-related maculopathy in the European Eye Study (EUREYE) are similar to other population-based studies in Western populations.

Retinal Vessel Diameters and Risk of Hypertension

Generalized retinal arteriolar narrowing is an important sign of systemic hypertension, and a lower arteriolar:venular diameter ratio predicts the risk of hypertension. We investigated whether this association was based on arteriolar or venular diameters or both. This study was based on the prospective population-based Rotterdam Study (1990-1993) and included 1900 participants (> or =55 years of age) of whom 739 persons had normal blood pressure (systolic <120 mm Hg and diastolic <80 mm Hg) and 1161 prehypertension (systolic 120 to 139 mm Hg or diastolic 80 to 89 mm Hg). For each participant, retinal arteriolar and venular diameters were measured on digitized images of 1 eye. After a mean follow-up of 6.6 years, 808 persons developed hypertension, defined as either systolic blood pressure > or =140 mm Hg or diastolic blood pressure > or =90 mm Hg or use of antihypertensive medication. Adjusted for age, gender, follow-up time, body mass index, smoking, diabetes mellitus, total and high-density lipoprotein cholesterol, C-reactive protein, and intima-media thickness, arteriolar narrowing was associated with an increased risk of hypertension (odds ratio per SD: 1.38; 95% CI, 1.23 to 1.55); for venular narrowing this was less striking (OR: 1.17; 95% CI, 1.04 to 1.32). Each SD decrease in the arteriolar:venular diameter ratio significantly increased the risk of hypertension by 24%. To examine the effect of baseline blood pressure, we stratified persons into those with "normal blood pressure" or "prehypertension." Within these strata, arteriolar narrowing was still related to incident hypertension. These data show that both retinal arteriolar and venular narrowing may precede the development of systemic hypertension.

Dietary intake of antioxidants and risk of age-related macular degeneration

CONTEXT

Age-related macular degeneration (AMD) is the most prevalent cause of irreversible blindness in developed countries. Recently, high-dose supplementation with beta carotene, vitamins C and E, and zinc was shown to slow the progression of AMD.

OBJECTIVE

To investigate whether regular dietary intake of antioxidants is associated with a lower risk of incident AMD.

DESIGN

Dietary intake was assessed at baseline in the Rotterdam Study (1990-1993) using a semiquantitative food frequency questionnaire. Incident AMD until final follow-up in 2004 was determined by grading fundus color transparencies in a masked way according to the International Classification and Grading System.

SETTING

Population-based cohort of all inhabitants aged 55 years or older in a middle-class suburb of Rotterdam, the Netherlands.

PARTICIPANTS

Of 5836 persons at risk of AMD at baseline, 4765 had reliable dietary data and 4170 participated in the follow-up.

MAIN OUTCOME MEASURE

Incident AMD, defined as soft distinct drusen with pigment alterations, indistinct or reticular drusen, geographic atrophy, or choroidal neovascularization.

RESULTS

Incident AMD occurred in 560 participants after a mean follow-up of 8.0 years (range, 0.3-13.9 years). Dietary intake of both vitamin E and zinc was inversely associated with incident AMD. The hazard ratio (HR) per standard deviation increase of intake for vitamin E was 0.92 (95% confidence interval [CI], 0.84-1.00) and for zinc was 0.91 (95% CI, 0.83-0.98). An above-median intake of all 4 nutrients, beta carotene, vitamin C, vitamin E, and zinc, was associated with a 35% reduced risk (HR, 0.65; 95% CI, 0.46-0.92) of AMD. Exclusion of supplement users did not affect the results.

CONCLUSION

In this study, a high dietary intake of beta carotene, vitamins C and E, and zinc was associated with a substantially reduced risk of AMD in elderly persons.

Retinal vessel diameters and the risk of incident age-related macular disease: the Rotterdam Study

PURPOSE

To study the relationship between retinal vessel diameters and incident age-related macular disease (iAMD).

DESIGN

Prospective population-based cohort study.

PARTICIPANTS

Persons (55 years and older) from the Rotterdam Study, who participated at the baseline (1990-1993) and 1 of 2 follow-up examinations (1993-1994 and 1997-1999).

METHODS

In the current analysis, 4345 participants who were free of AMD at baseline and had gradable macular transparencies at both baseline and follow-up examination were included. Also, arteriolar and venular diameters were measured on digitized baseline images. Stereoscopic transparencies of the macular region were graded according to the International Classification and Grading System for AMD. Incidence of AMD was defined as the development of soft distinct drusen with pigmentary changes or indistinct or reticular drusen with or without pigmentary changes (early iAMD) or atrophic or neovascular AMD (late iAMD). Logistic regression models were used to assess these associations, adjusting for age, gender, and follow-up time and, additionally, for smoking, body mass index, intima-media thickness, systolic blood pressure, and total and high-density lipoprotein cholesterol levels.

MAIN OUTCOME MEASURE

Incidence of AMD.

RESULTS

After a mean follow-up time of 5.2 years, a total of 374 persons developed early and late iAMD. Neither arteriolar nor venular diameters were related to the risk of iAMD. The odds ratio (OR) per standard deviation (SD) decrease in arteriolar diameter was 1.03 (95% confidence interval [CI], 0.93-1.15), and the OR per SD increase in venular diameter was 1.04 (95% CI, 0.93-1.16). After categorizing the retinal vessel diameters into quintiles, there was no trend. After stratifying on age, only persons 75 years and older with smaller arteriolar diameters were at a borderline significant increased risk of iAMD: OR/SD decrease in arteriolar diameters adjusted for age, gender, follow-up time, and other cardiovascular risk factors, 1.24 (95% CI, 0.94-1.63).

CONCLUSION

Overall retinal vessel diameters were not related to the risk of iAMD in this general elderly population.

Associations between the deletion polymorphism of the angiotensin 1-converting enzyme gene and ocular signs of primary open-angle glaucoma

BACKGROUND

Primary open-angle glaucoma (POAG) is a leading cause of blindness. High intraocular pressure (IOP) has been shown to be a key risk factor for POAG. Topical application of angiotensin 1-converting enzyme (ACE) inhibitors has been shown to lower IOP, and angiotensin-induced increase in vascular tone has been implicated as a pathogenetic mechanism in glaucomatous cupping and damage to the optic nerve. The objective of this study was to investigate the association between the deletion polymorphism in the ACE gene and ocular signs of POAG.

METHODS

Baseline data from the Rotterdam Study was used. The ACE genotype was determined in 6,462 subjects. We used univariate and multiple variable statistical techniques to examine associations between ACE genotype and each of ocular hypertension, glaucomatous optic neuropathy, glaucomatous visual field defects and POAG diagnosis.

RESULTS

We found no consistent evidence between ACE genotype and ocular signs of POAG. We did, however, find evidence of an association between ACE genotype and optic disc area, subjects homozygous for the deletion allele tending to have fractionally smaller optic disc areas than those with a single deletion allele subjects, who in turn tended to have fractionally smaller optic discs than those with no deletion alleles (P=0.01).

CONCLUSIONS

The data provided little evidence of any association between ocular signs of POAG and the deletion polymorphism of ACE. There was, however, evidence that ACE may be associated with optic disc size-this was an unexpected finding.

Are retinal arteriolar or venular diameters associated with markers for cardiovascular disorders? The Rotterdam Study

PURPOSE

A lower retinal arteriolar-to-venular ratio (AVR) has been suggested to reflect generalized arteriolar narrowing and to predict the risk of cardiovascular diseases. The contribution of the separate arteriolar and venular diameters to this AVR is unknown. Thus, associations between retinal arteriolar and venular diameters, and the AVR on the one hand and blood pressure, atherosclerosis, inflammation markers, and cholesterol levels on the other were examined in the Rotterdam Study.

METHODS

In this cross-sectional population-based study, for one eye of each subject (> or =55 years; n = 5674), retinal arteriolar and venular diameters (in micrometers) of the blood columns were summed on digitized images. At baseline blood pressures, cholesterol levels, and markers of atherosclerosis and inflammation were also measured.

RESULTS

With increasing blood and pulse pressures, retinal arteriolar and venular diameters and the AVR decreased significantly and linearly. Lower arteriolar diameters were associated with increased carotid intima-media thickness. Larger venular diameters were associated with higher carotid plaque score, more aortic calcifications, lower ankle-arm index, higher leukocyte count, higher erythrocyte sedimentation rate, higher total serum cholesterol, lower HDL, higher waist-to-hip ratio, and smoking. A lower AVR was related to increased carotid intima-media thickness, higher carotid plaque score, higher leukocyte count, lower HDL, higher body mass index, higher waist-to-hip ratio, and smoking.

CONCLUSIONS

Because larger venular diameters are associated with atherosclerosis, inflammation, and cholesterol levels, the AVR does not depend only on generalized arteriolar narrowing due to the association between smaller arteriolar diameters and higher blood pressures. These data indicate that retinal venular diameters are variable and may play their own independent role in predicting cardiovascular disorders.

Risk factors for incident age-related macular degeneration

OBJECTIVE

To examine risk factors for incident age-related macular degeneration (AMD) after combining data from 3 population-based cohort studies.

DESIGN

Population-based cohort study.

POPULATION

A population of 9523 adults (age range, 43-95 years at baseline) living in Australia, The Netherlands, and the United States who participated in a baseline examination and a follow-up examination on average 5 or 6 years later.

METHODS

Similar procedures were used at all study sites. Examinations included a standardized questionnaire, pupillary dilation, and stereoscopic color fundus photography. Fundus photographs were graded for lesions associated with AMD using the Wisconsin and International Age-Related Maculopathy Grading Systems. Senior investigators from each site adjudicated all photos graded as late AMD.

MAIN OUTCOMES MEASURE

Incidence of late AMD.

RESULTS

Among studies, distributions for most risk factors differed, and overall incidence rates were similar. In the Beaver Dam Eye Study, total serum cholesterol was inversely associated with incident neovascular AMD. In the Blue Mountains Eye Study, current smoking (defined as smoking at the time of the baseline examination) was associated with an increased risk of incident geographic atrophy and late AMD; increased total serum cholesterol, having diabetes, and older age at menopause were positively associated with incident geographic atrophy; and an increase in high-density lipoprotein serum cholesterol was inversely related to incident geographic atrophy. In the Rotterdam Study, current smoking was associated with an increased risk of incident geographic atrophy, neovascular AMD, and late AMD; past smoking was associated with an increased risk of incident neovascular AMD and late AMD; and an increased number of years between menarche and menopause was directly related to incident geographic atrophy. After pooling data, the only statistically significant relationships found were between smoking and total serum cholesterol and incident AMD. Current smoking was associated with an increased incidence of geographic atrophy and late AMD (odds ratios [ORs] relative to nonsmokers: 2.83 and 2.35, respectively; ORs relative to past smokers: 2.80 and 1.82, respectively), and total serum cholesterol was associated directly with incident geographic atrophy (OR: 1.08 per 10 mg/dl) and inversely with incident neovascular AMD (OR: 0.94 per 10 mg/dl).

CONCLUSIONS

Pooled data support a growing body of evidence indicating that smoking is related to an increased risk of incident AMD. Current smokers were at higher risk of incident AMD than both past smokers and those who never smoked. The relationships found in this study between total serum cholesterol and incident geographic atrophy and neovascular AMD are not readily explained.

Is medication use associated with the incidence of early age-related maculopathy? Pooled findings from 3 continents

OBJECTIVE

To investigate whether there is an association between the use of medication and the incidence of early age-related maculopathy (ARM).

DESIGN

Pooled data from 3 prospective, population-based cohort studies.

PARTICIPANTS

Subjects without early and late ARM at baseline who participated in the follow-up of the Beaver Dam Eye Study (n = 3012), the Rotterdam Study (n = 3434), and the Blue Mountains Eye Study (n = 2203).

METHODS

Stereoscopic color fundus photographs of all participants were graded according to a standardized protocol. At baseline, current use of prescription and over-the-counter medication was assessed by interview, and the drug name was confirmed at the research centers. Procedures and definitions were similar at both baseline and follow-up across the 3 study sites.

MAIN OUTCOME MEASURES

Incidence of early ARM, defined as the presence at follow-up of either soft distinct drusen with pigmentary changes or soft indistinct or reticular drusen.

RESULTS

In the pooled cohort, 53.3% of participants used at least one of the medications selected for this study. Within a mean period of 5.6 years, a total of 683 subjects developed early ARM. Users of antihypertensive medication in general, and beta-blockers in particular, had a borderline statistically significant increased risk of early ARM (odds ratio [OR] for beta-blockers, 1.3; 95% confidence interval [CI], 1.0-1.6) when adjusted for systolic (or diastolic) blood pressure and other confounders. A protective effect of borderline significance was found among women using hormone replacement therapy (OR, 0.6; 95% CI, 0.4-1.0) and in persons using tricyclic antidepressants (OR, 0.4; 95% CI, 0.2-1.0). In contrast with beta-blockers, the direction and magnitude of the association with hormone replacement therapy and tricyclic antidepressants were inconsistent among the 3 study populations.

CONCLUSIONS

Pooled data from 3 population-based studies showed no strong associations between medication use and the incidence of early ARM. Of borderline significance were a slightly increased risk among users of beta-blockers and a reduced risk among users of hormone replacement therapy and users of tricyclic antidepressants. Although beta-blocker use could be a proxy for systemic hypertension, these findings warrant further investigations, preferably including information on the dosage and duration of drug exposure.

Prevalence of cataract and pseudophakia/aphakia among adults in the United States

OBJECTIVES

To determine the prevalence of cataract and pseudophakia/aphakia in the United States and to project the expected change in these prevalence figures by 2020.

METHODS

Summary prevalence estimates of cataract and of pseudophakia/aphakia were prepared separately for black, white, and Hispanic persons (for whom only cataract surgery data were available) in 5-year age intervals starting at 40 years for women and men. The estimates were based on a standardized definition of various types of cataract: cortical, greater than 25% of the lens involved; posterior subcapsular, present according to the grading system used in each study; and nuclear, greater than or equal to the penultimate grade in the system used. Data were collected from major population-based studies in the United States, and, where appropriate, Australia, Barbados, and Western Europe. The age-, gender-, and race/ethnicity-specific rates were applied to 2000 US Census data, and projected population figures for 2020, to obtain overall estimates.

RESULTS

An estimated 20.5 million (17.2%) Americans older than 40 years have cataract in either eye, and 6.1 million (5.1%) have pseudophakia/aphakia. Women have a significantly (odds ratio = 1.37; 95% confidence interval, 1.26-1.50) higher age-adjusted prevalence of cataract than men in the United States. The total number of persons who have cataract is estimated to rise to 30.1 million by 2020; and for those who are expected to have pseudophakia/aphakia, to 9.5 million.

CONCLUSION

The number of Americans affected by cataract and undergoing cataract surgery will dramatically increase over the next 20 years as the US population ages.

Cholesterol and age-related macular degeneration: is there a link?

PURPOSE

To examine the relation among serum cholesterol, apolipoprotein E genotype (APOE), and the risk of early and late age-related macular degeneration (AMD).

DESIGN

The Rotterdam Study, a population based prospective cohort study.

METHODS

Serum levels of total and high-density lipoprotein (HDL) cholesterol as well as APOE genotype were determined at baseline. Of 3,944 subjects, 400 were diagnosed with incident early and late AMD after a mean follow-up of 5.2 years.

RESULTS

Serum HDL, but not total, cholesterol was associated with an increased risk of AMD (odds ratio/SD, 1.20; 95% confidence interval; 1.06-1.35). The association remained unchanged after adjustment for APOE genotype. When stratifying for APOE genotype, the association was strongest in persons with the e 4 allele; an inverse association seemed to be present for e 2 carriers.

CONCLUSION

Elevated HDL but not total cholesterol is associated with an increased risk of AMD. Apolipoprotein E genotype does not explain this association but may be an effect modifier.

Epidemiology of age-related maculopathy: a review

Age-related maculopathy (ARM) is a degenerative disease of the retina and the leading cause of incurable blindness and visual impairment in industrialized countries. By definition, ARM is confined to the age-category above 50 years. The aetiology of ARM is still unknown, despite intensive research on many fronts. In this paper, we provide a review of the epidemiology of ARM. The most prominent findings were an exponential increase in frequency with age, a significant familial and genetic component, and a strong association with smoking. Other risk factors that were found less consistently were atherosclerosis, low intake of antioxidant nutrients, and cataract extraction. Future studies, both observational and experimental, will hopefully identify more risk factors that are amenable to prevention.

Relationship between refraction and prevalent as well as incident age-related maculopathy: the Rotterdam Study

PURPOSE

To study the relationship between baseline spherical equivalents (SphE) of refraction and prevalent as well as incident age-related maculopathy (pARM and iARM, respectively).

METHODS

The study was performed as part of the Rotterdam Study, a population-based, prospective cohort study. The SphE (in diopters), measured with autorefraction and subjective optimization, was recorded in 6209 subjects aged 55 years or more. Aphakic or pseudophakic eyes at baseline were excluded. Stereoscopic transparencies of the macular region were graded according to the International Classification and Grading System. ARM was defined as large soft drusen with pigmentary changes, or indistinct drusen, or atrophic or neovascular age-related macular degeneration (AMD). For the prevalence analyses, ARM was classified into no, p(early)ARM, or pAMD, and in each subject the eye with the most advanced ARM and the corresponding refraction was selected. After a mean 5.2 years of follow-up, 4935 subjects had complete data for these incidence analyses. In each subject, the eye with iARM was selected.

RESULTS

The age- and gender-adjusted odds ratio (OR) of pARM (n = 536) for every diopter of progress toward hyperopia was 1.09 (95% confidence interval [CI]1.04-1.13). For p(early)ARM (n = 440) the OR was 1.09 (1.04-1.14) and for pAMD (n = 96) the OR was 1.09 (1.00-1.19). Baseline refraction was significantly associated with increased risk of iARM (n = 497). For each diopter of progress toward hyperopia the OR was 1.05 (95% CI 1.01-1.10). Additional adjustments for smoking, atherosclerosis, and blood pressure did not alter the relationship.

CONCLUSIONS

These population-based incidence data confirm results from prevalence and case-control studies that there is an association between hyperopia and ARM.

Blood pressure, atherosclerosis, and the incidence of age-related maculopathy: the Rotterdam Study

PURPOSE

To determine whether blood pressure and subclinical atherosclerosis are associated with incident age-related maculopathy (ARM).

METHODS

The study was performed within the Rotterdam Study, a population-based, prospective cohort study in Rotterdam, The Netherlands. A total of 4822 subjects who at baseline were aged 55 years more, were free of ARM, and participated in at least one of two follow-up examinations after a mean of 2 and 6.5 years, were included in the study. At baseline, blood pressure and the presence of atherosclerosis were determined. ARM was assessed according to the International Classification and Grading System and defined as large, soft drusen with pigmentary changes; indistinct drusen; or atrophic or neovascular age-related macular degeneration.

RESULTS

After a mean follow-up of 5.2 years, incident ARM was diagnosed in 417 subjects. Increased systolic blood pressure or pulse pressure was associated with a higher risk of ARM. Adjusted for age, gender, smoking, total and high-density lipoprotein cholesterol, body mass index, and diabetes mellitus, odds ratios (OR) per 10-mm Hg increase were 1.08 (95% confidence interval [CI]: 1.03-1.14) and 1.11 (95% CI: 1.04-1.18), respectively. Moreover, different measures of atherosclerosis were associated with the risk of ARM. An increase in carotid wall thickness (OR per 1 SD, 1.15; 95% CI: 1.03-1.28) increased the risk of ARM. The lowest compared with the highest tertile of ankle-arm index had an OR of 1.32 (95% CI: 1.00-1.75). A weak association was found between aortic calcifications and the risk of ARM.

CONCLUSIONS

Elevated systolic blood or pulse pressure or the presence of atherosclerosis may increase the risk of development of ARM.

Grading of age-related maculopathy for epidemiological studies: is digital imaging as good as 35-mm film?

PURPOSE

To compare stereo digital images with stereo 35-mm color transparencies as to the quality and reliability of grading age-related maculopathy (ARM) in the context of a multicenter European epidemiologic study (the EUREYE Study).

DESIGN

Instrument validation study.

PARTICIPANTS

Ninety-one subjects (137 eyes) with varying degrees of ARM, including no ARM.

METHODS

From both eyes of the participants, 35-mm film and digital stereoscopic fundus images were obtained with two identical Topcon fundus cameras. Two experienced graders classified all signs of ARM according to the International Classification System. Agreement between imaging techniques and between graders was calculated using the weighted kappa statistic.

MAIN OUTCOME MEASURES

Signs of ARM (number, size, and morphologic characteristics of drusen; pigmentary changes; geographic atrophy; and neovascular macular degeneration) as well as an overall staging system of increasing ARM severity.

RESULTS

The weighted kappa value for between-technique agreement ranged from 0.41 for number of drusen <63 microm to 0.79 for drusen type and total area occupied by drusen. The kappa values for atrophic and neovascular end-stage ARM were 0.87 and 0.94, respectively. The between-technique agreement on stages of ARM was approximately 0.76. The agreement between graders was largely the same for both techniques of imaging.

CONCLUSIONS

In the described setting, digital images were as good as 35-mm film for the grading of ARM. Considering the practical advantages of digital imaging, this technique may serve well in epidemiologic studies of ARM.

The risk and natural course of age-related maculopathy: follow-up at 6 1/2 years in the Rotterdam study

OBJECTIVES

To evaluate the natural course of age-related maculopathy (ARM) and to assess the incidence and absolute risk of its final stage, age-related macular degeneration (AMD).

METHODS

In a population-based prospective cohort study of 6418 persons 55 years and older, we studied the incidence and natural course of ARM. Subjects underwent identical examinations, including stereoscopic fundus photography, at baseline and at 2.0 and 6(1/2) years' follow-up. Age-related maculopathy was graded according to the International Classification and Grading System for ARM and AMD, and stratified into 5 exclusive stages. Incidence was expressed in rates and 5-year absolute risks.

RESULTS

At follow-up, 47 new cases of AMD were identified, with a ratio of neovascular-atrophic AMD of 1.4:1. The 5-year risk of AMD increased with more severe stages to 28.0% for subjects 55 years and older with indistinct drusen and pigmentary irregularities (stage 3). Age, but not sex, independently increased this risk to a maximum of 42.0% for subjects with stage 3 ARM who were 80 years and older. Individual ARM fundus signs that predicted best the development of AMD were 10 or more large drusen (> or =125 microm) and 10% or more of the grid area covered by drusen. Subjects who developed atrophic AMD showed no significant (P =.25) differences in baseline fundus signs and natural course compared with subjects who developed neovascular AMD.

CONCLUSIONS

We provided the absolute risk of AMD as a function of age and early ARM fundus signs, and showed that both are prominent independent risk factors. The progression of ARM stages follows, after the appearance of the first soft drusen, a distinct course at a gradual pace that accelerates with increasing age.

Side effects after radiotherapy of age-related macular degeneration with the Nijmegen technique

BACKGROUND

In a randomized trial concerning radiotherapy for age-related macular degeneration, fluorescein angiograms were taken of controls and patients. In this study the frequency of side effects in eyes receiving radiotherapy with the Nijmegen technique is compared with the findings in the eyes of controls.

METHODS

Patients receiving treatment were irradiated by two isocentric photon beams in four fractions of 6 Gy that were directed to the macular area at 30 degrees and -30 degrees with regard to the optical axis. The most recent fluorescein angiograms of the randomized eyes (32 treated and 31 control eyes) were scored by two independent researchers, using a scoring form with nine features of radiation retinopathy: nonperfusion, macular edema, microaneurysms, retinal hemorrhages, cotton-wool spots, perifoveal telangiectasis, vascular sheathing, retinal neovascularization, and radiation-associated choroidal neovasculopathy. The results were graded as: no retinopathy (grade 0), mild retinopathy (grade 1), moderate retinopathy (grade 2), and severe retinopathy (grade 3).

RESULTS

In the treated group 6 patients (18.8%) were grade 1, 10 patients (31.2%) were grade 2 and 7 patients (21.9%) were grade 3. In the control group 9 patients (29.0%) were grade 1, 11 patients (35.5%)were grade 2 and 2 patients (6.5%) were grade 3. There were no patients with retinal neovascularization.

CONCLUSION

With the Nijmegen technique a relatively high dose of radiation can be applied to a small retinal area. In only a minority of cases does some evidence of radiation retinopathy occur.

Incidence and progression rates of age-related maculopathy: the Rotterdam Study

PURPOSE

To describe the incidence rate of age-related macular degeneration (AMD) and the progression rates of early stages of age-related maculopathy (ARM), and to study the hierarchy of fundus features that determine progression.

METHODS

A group of 4953 subjects aged 55 years and older living in Rotterdam, The Netherlands, was studied at baseline and at 2-year follow-up to determine the incidence of neovascular and atrophic AMD. A subgroup of 1244 subjects was studied for progression of early stages of ARM. Fundus transparencies were graded for features of ARM using the International Classification System. ARM was stratified in four exclusive stages, according to type of drusen and presence of pigmentary irregularities.

RESULTS

The overall 2-year cumulative incidence of AMD was 0.2%, increasing to 1.8% in subjects of 85 years and older. Of those in the early stages, one fourth showed progression to a more severe stage. The most important predictors for progression were more than 10% of macular area covered by drusen (odds ratio [OR] 5.7, 95% confidence interval [CI] 2.9-11.3), presence of depigmentation (OR 4.0, 95% CI 2.5-6.4), and hyperpigmentation (OR 3.4, 95% CI 2.1-5.4).

CONCLUSIONS

The incidence of AMD appears to be lower in The Netherlands than in the United States. Progression of early ARM stages occurs in a distinct pattern at a stable rate, with a large area of drusen and presence of pigmentary changes as the most important predictors.

Is open-angle glaucoma associated with early menopause? The Rotterdam Study

The authors examined the association between age at menopause and open-angle glaucoma among women aged > or = 55 years in the population-based Rotterdam Study (1990--1993). Information on age and type of menopause was obtained by interview. Subjects (n = 3,078) were stratified into three categories according to age at menopause: <45 years, 45--49 years, and > or = 50 years, with the last group serving as the reference group. Diagnosis of open-angle glaucoma was based on the presence of a glaucomatous visual field defect and glaucomatous optic neuropathy. Open-angle glaucoma was diagnosed in 78 women with a natural menopause and 15 women with an artificial menopause. In the category of natural menopause, women who went through menopause before reaching the age of 45 years had a higher risk of open-angle glaucoma than the reference group (odds ratio = 2.6; 95% confidence interval: 1.5, 4.8), after adjustment for age and use of hormone replacement therapy. Among women who went through menopause between the ages of 45 and 49 years, the odds ratio was 1.1 (95% confidence interval: 0.7, 2.0). These findings suggest that early menopause is associated with a higher risk of open-angle glaucoma.