B. E. K. Klein

An international classification and grading system for age-related maculopathy and age-related macular degeneration

A common detection and classification system is needed for epidemiologic studies of age-related maculopathy (ARM). Such a grading scheme for ARM is described in this paper. ARM is defined as a degenerative disorder in persons > or = 50 years of age characterized on grading of color fundus transparencies by the presence of the following abnormalities in the macular area: soft drusen > or = 63 microns, hyperpigmentation and/or hypopigmentation of the retinal pigment epithelium (RPE), RPE and associated neurosensory detachment, (peri)retinal hemorrhages, geographic atrophy of the RPE, or (peri)retinal fibrous scarring in the absence of other retinal (vascular) disorders. Visual acuity is not used to define the presence of ARM. Early ARM is defined as the presence of drusen and RPE pigmentary abnormalities described above; late ARM is similar to age-related macular degeneration (AMD) and includes dry AMD (geographic atrophy of the RPE in the absence of neovascular AMD) or neovascular AMD (RPE detachment, hemorrhages, and/or scars as described above). Methods to take and grade fundus transparencies are described.

Global prevalence and major risk factors of diabetic retinopathy

OBJECTIVE To examine the global prevalence and major risk factors for diabetic retinopathy (DR) and vision-threatening diabetic retinopathy (VTDR) among people with diabetes. RESEARCH DESIGN AND METHODS A pooled analysis using individual participant data from population-based studies around the world was performed. A systematic literature review was conducted to identify all population-based studies in general populations or individuals with diabetes who had ascertained DR from retinal photographs. Studies provided data for DR end points, including any DR, proliferative DR, diabetic macular edema, and VTDR, and also major systemic risk factors. Pooled prevalence estimates were directly age-standardized to the 2010 World Diabetes Population aged 20–79 years. RESULTS A total of 35 studies (1980–2008) provided data from 22,896 individuals with diabetes. The overall prevalence was 34.6% (95% CI 34.5–34.8) for any DR, 6.96% (6.87–7.04) for proliferative DR, 6.81% (6.74–6.89) for diabetic macular edema, and 10.2% (10.1–10.3) for VTDR. All DR prevalence end points increased with diabetes duration, hemoglobin A1c, and blood pressure levels and were higher in people with type 1 compared with type 2 diabetes. CONCLUSIONS There are approximately 93 million people with DR, 17 million with proliferative DR, 21 million with diabetic macular edema, and 28 million with VTDR worldwide. Longer diabetes duration and poorer glycemic and blood pressure control are strongly associated with DR. These data highlight the substantial worldwide public health burden of DR and the importance of modifiable risk factors in its occurrence. This study is limited by data pooled from studies at different time points, with different methodologies and population characteristics.

The Wisconsin Epidemiologic Study of Diabetic Retinopathy: XI. The Incidence of Macular Edema

As part of a population-based study of diabetes mellitus, the 4-year incidence of macular edema and its relationship to various risk factors was examined in a group of younger onset insulin-taking persons (n = 610) and older onset persons (n = 652). The presence of macular edema at the baseline and follow-up examinations was determined from gradings of stereoscopic fundus photographs. The overall incidence of macular edema in the younger onset group was 8.2% (50/610); in the group of older onset persons using insulin, 8.4% (23/273) and in the group of those not using insulin, 2.9% (11/379). The incidence of macular edema was associated with higher level of glycosylated hemoglobin, longer duration of diabetes, and more severe retinopathy at the baseline examination in both younger and older onset groups. These data provide accurate population-based estimates of incidence of macular edema, and suggest that the level of glycemia is a significant risk factor for the development of macular edema.

The association between serum uric acid level and long-term incidence of hypertension: population-based cohort study

Increasing experimental evidence, including recently developed animal models support a causal role for uric acid in the development of hypertension. However, it is not clear whether serum uric acid levels are independently associated with the long-term incidence of hypertension. We examined the association between serum uric acid levels and 10-year incidence of hypertension in a population-based cohort study based in Beaver Dam city and township, Wisconsin, US. We studied 2520 hypertension-free individuals (56.3% women, age: 43–84 years, 98% Caucasian) at the baseline examination (1988–1990). The main outcome of interest was hypertension (systolic blood pressure (BP) of 140 mm Hg or higher, diastolic BP 90 mm Hg or higher, or combination of self-reported high BP diagnosis and use of antihypertensive medications) incidence over 10 years among baseline normotensive individuals. Nine hundred and fifty-six individuals developed hypertension over a 10-year follow-up period. The relative risk (RR) (95% confidence intervals (CI)) of incident hypertension increased in a dose-dependent manner (P-trend<0.05 in all models) with increasing uric acid quartiles. Multivariable RR (95% CI) comparing the highest quartile of serum uric acid (⩾390 μmol/l) to the lowest quartile (⩽260 μmol/l) was 1.65 (1.41–1.93). This association persisted in subgroup analyses by categories of smoking, alcohol intake, body mass index, baseline blood pressure and estimated glomerular filtration rate (GFR). In conclusion, increasing quartiles of serum uric acid was associated with 10-year incidence of hypertension independent of smoking, alcohol intake and baseline kidney function suggesting an independent positive association between serum uric acid levels and hypertension development among community-dwelling older adults.

Relation of ocular trauma to cortical, nuclear, and posterior subcapsular cataracts: the Beaver Dam Eye Study

Background: The consequences of minor ocular trauma in the general population are unclear. The relation of self reported ocular trauma to cortical, nuclear, and posterior subcapsular cataracts is described in a defined population. Methods: Population based, cross sectional study involving all people aged 43 to 86 years, living in Beaver Dam, Wisconsin (n=4926). Ocular trauma was ascertained by interview and cataract was graded from lens photographs. The relation of ocular trauma to cortical, nuclear, and posterior subcapsular cataracts was examined. Results: People with a history of ocular trauma were more likely to have cortical (odds ratio (OR): 1.5; 95% confidence interval (CI): 1.0 to 2.2) and posterior subcapsular (OR: 1.7; 95% CI: 1.0 to 3.1) cataracts, compared to people without a history of trauma. These associations were stronger for people with previous trauma caused by a blunt object (OR: 3.3; 95% CI: 1.6 to 6.9 for cortical cataract, and OR: 4.1; 95% CI: 1.5 to 10.8 for posterior subcapsular cataracts). However, in analyses comparing the frequencies of cataract between traumatised and non-traumatised eyes among people with unilateral ocular trauma, the ocular trauma association for cortical cataract was no longer present, although the association for posterior subcapsular cataract persisted (OR: 2.4; 95% CI: 0.8 to 7.8). Conclusion: The data provide evidence of a possible association between self reported ocular trauma and posterior subcapsular cataract.

The use of hearing protection devices by older adults during recreational noise exposure

A population-based study to assess the use of hearing protection devices by older adults during noisy recreational activities was performed. The population-based Epidemiology of Hearing Loss Study was designed to measure the prevalence of hearing loss in adults residing in Beaver Dam, Wisconsin. The use of hearing protection devices during noisy recreational activities was assessed by performing three examinations over a period of 10 years (1993-1995, no. of participants (n)=3753, aged 48-92 years; 1998-2000, n=2800, aged 53-97 years; 2003-2005, n=2395, aged 58-100 years). The recreational activities included hunting, target shooting, woodworking/carpentry, metalworking, driving loud recreational vehicles, and performing yard work using either power tools or a chain saw. The prevalence of using hearing protection devices during any of these activities increased with time (9.5%, 15.0%, and 19.9% at baseline, 5 years, and 10 years, respectively). However, the use of hearing protection devices remained low for most activities. Those under the age of 65 were twice as likely to use hearing protection devices during noisy activities than were older adults. Men, those with a hearing handicap, and those with significant tinnitus were more likely to use hearing protection devices. Smokers and the less educated were less likely to use hearing protection devices. The results demonstrated that many adults expose themselves to potentially damaging recreational noise, leaving them at risk for hearing loss.

Hypertension genes and retinal vascular calibre: the Cardiovascular Health Study

We examined the associations of single nucleotide polymorphisms (SNPs) in three candidate hypertension genes, α-adducin (ADD1/G460W), β2-adrenergic receptor (ADRB2/Arg16Gly and Gln27Glu) and G-protein β3 subunit (GNB3/C825T), with retinal arteriolar calibre (an intermediate marker of chronic hypertension) and venular calibre. Data in 1842 participants (1554 whites and 288 African Americans) aged 69–96 years from the Cardiovascular Health Study with genotype and retinal vascular calibre data were included. A computer-assisted method was used to measure retinal vascular calibre. We analysed four SNPs and multilocus interaction for three genes. All SNPs were in Hardy–Weinberg equilibrium in whites and African Americans. The study had sufficient power to detect 0.5% of the total variance of retinal vascular calibre contributed by each SNP in the total population, except for the GNB3 gene variant. No significant associations between these SNPs in the genes studied and mean retinal arteriolar and venular calibre were found in single-gene or multilocus analysis (for example, age-, gender-, race-adjusted mean retinal arteriolar calibre was similar between participants who were ADD1/460W homozygotes and ADD1/G allele carriers, 166.2 vs 167.7 μm). In conclusion, this study found no evidence of an association of SNPs in candidate hypertension genes studied here with retinal vascular calibre.

Lp(a) is not related to retinopathy in diabetic subjects

Purpose To examine the association between Lp(a) concentrations and the severity of retinopathy in 22 younger-onset and 48 older-onset diabetic subjects from the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR), a population-based study of diabetic retinopathy. Methods We used a subset of the WESDR population with standardized protocols and stereoscopic color fundus photography to determine the severity of diabetic retinopathy in relation to Lp(a) concentrations. Lp(a) concentrations were measured by a monoclonal anti-Lp(a) antibody. Results Lp(a) levels were not significantly different between younger-onset or older-onset subjects with and without retinopathy. Conclusion Our results do not support a link between higher levels of Lp(a) and severe retinopathy in either younger-onset or older-onset diabetic subjects but this needs confirmation in larger prospective studies.

A pilot study of glaucoma visual field screening in diabetes

Because people with diabetes may be at increased risk of glaucoma, we performed a pilot study using automated visual field testing for screening them. One hundred and seventy-six diabetic persons who had participated in the Wisconsin Epidemiologic Study of Diabetic Retinopathy were tested with the Armaly-Drance screening pattern on the Humphrey Visual Field Analyzer. Individuals with moderate diabetic retinopathy or worse tended to have lower sensitivity of the central visual field and missed more points than those with no or only mild retinopathy. People with a history of glaucoma had slightly less sensitivity and missed more points than controls. These preliminary findings suggest that although people with diabetes and glaucoma may more frequently have visual field defects than people with diabetes but no glaucoma, a larger study is needed. This pilot study shows that such a study would be feasible and should be designed to indicate the sensitivity, specificity, and cost-benefit ratio of a screening program so as to assess the utility of the screening visual field test for finding glaucoma amongst people with diabetes.

An anatomic index for the severity of ocular injuries

Ocular injuries are a frequent cause of monocular blindness and cause disfigurement and discomfort. We developed a measure of severity for eye injuries using a multi-attribute utility (MAU) model. The severity index scoring was applied to eye injuries that presented at hospitals in Wisconsin, U.S.A. The resulting distribution of severities was compatible with that seen by general eye care physicians. A severity scale provides a means of comparing the severity of injuries from a wide variety of traumatic sources (e.g. automobile crashes, combat injuries, occupational accidents, etc.) and is useful in evaluating preventive and public health measurements.