Causes and Prevalence of Visual Impairment Among Adults in the UnitedStates

OBJECTIVES

To estimate the cause-specific prevalence and distribution of blindness and low vision in the United States by age, race/ethnicity, and gender, and to estimate the change in these prevalence figures over the next 20 years.

METHODS

Summary prevalence estimates of blindness (both according to the US definition of < or =6/60 [< or =20/200] best-corrected visual acuity in the better-seeing eye and the World Health Organization standard of < 6/120 [< 20/400]) and low vision (< 6/12 [< 20/40] best-corrected vision in the better-seeing eye) were prepared separately for black, Hispanic, and white persons in 5-year age intervals starting at 40 years. The estimated prevalences were based on recent population-based studies in the United States, Australia, and Europe. These estimates were applied to 2000 US Census data, and to projected US population figures for 2020, to estimate the number of Americans with visual impairment. Cause-specific prevalences of blindness and low vision were also estimated for the different racial/ethnic groups.

RESULTS

Based on demographics from the 2000 US Census, an estimated 937 000 (0.78%) Americans older than 40 years were blind (US definition). An additional 2.4 million Americans (1.98%) had low vision. The leading cause of blindness among white persons was age-related macular degeneration (54.4% of the cases), while among black persons, cataract and glaucoma accounted for more than 60% of blindness. Cataract was the leading cause of low vision, responsible for approximately 50% of bilateral vision worse than 6/12 (20/40) among white, black, and Hispanic persons. The number of blind persons in the US is projected to increase by 70% to 1.6 million by 2020, with a similar rise projected for low vision.

CONCLUSIONS

Blindness or low vision affects approximately 1 in 28 Americans older than 40 years. The specific causes of visual impairment, and especially blindness, vary greatly by race/ethnicity. The prevalence of visual disabilities will increase markedly during the next 20 years, owing largely to the aging of the US population.

An international classification and grading system for age-related maculopathy and age-related macular degeneration. The International ARM Epidemiological Study Group

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.

Prevalence of age-related maculopathy. The Beaver Dam Eye Study

PURPOSE

The relationships of retinal drusen, retinal pigmentary abnormalities, and macular degeneration to age and sex were studied in 4926 people between the ages of 43 and 86 years who participated in the Beaver Dam Eye Study.

METHODS

The presence and severity of various characteristics of drusen and other lesions typical of age-related maculopathy were determined by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.

RESULTS

One or more drusen were present in the macular area of at least 1 eye in 95.5% of the population. People 75 years of age or older had significantly higher frequencies (P less than 0.01) of the following characteristics than people 43 to 54 years of age: larger sized drusen (greater than or equal to 125 microns, 24.0% versus 1.9%), soft indistinct drusen (23.0% versus 2.1%), retinal pigment abnormalities (26.6% versus 7.3%), exudative macular degeneration (5.2% versus 0.1%), and geographic atrophy (2.0% versus 0%).

CONCLUSION

These data indicate signs of age-related maculopathy are common in people 75 years of age or older and may pose a substantial public health problem.

Age-related macular degeneration

Age-related macular degeneration is a leading cause of visual impairment and severe vision loss. Clinically, it is classified as early-stage (medium-sized drusen and retinal pigmentary changes) to late-stage (neovascular and atrophic). Age-related macular degeneration is a multifactorial disorder, with dysregulation in the complement, lipid, angiogenic, inflammatory, and extracellular matrix pathways implicated in its pathogenesis. More than 50 genetic susceptibility loci have been identified, of which the most important are in the CFH and ARMS2 genes. The major non-genetic risk factors are smoking and low dietary intake of antioxidants (zinc and carotenoids). Progression from early-stage to late-stage disease can be slowed with high-dose zinc and antioxidant vitamin supplements. Intravitreal anti-vascular endothelial growth factor therapy (eg, ranibizumab, aflibercept, or bevacizumab) is highly effective at treating neovascular age-related macular degeneration, and has markedly decreased the prevalence of visual impairment in populations worldwide. Currently, no proven therapies for atrophic disease are available, but several agents are being investigated in clinical trials. Future progress is likely to be from improved efforts in prevention and risk-factor modification, personalised medicine targeting specific pathways, newer anti-vascular endothelial growth factor agents or other agents, and regenerative therapies.

Prevalence of age-related maculopathy in Australia. The Blue Mountains Eye Study

PURPOSE

To examine the prevalence of age-related maculopathy (drusen and retinal pigmentary abnormalities) and end-stage age-related macular degeneration lesions (neovascular maculopathy or geographic atrophy) in a defined older Australian urban population.

SUBJECTS

All noninstitutionalized residents 49 years of age or older who were identified in a door-to-door census of two postcode areas west of Sydney, Australia.

METHODS

All participants received a detailed eye examination, including stereoscopic photographs of each macula. Two trained graders used the Wisconsin Age-related Maculopathy Grading System to assess the presence and severity of typical lesions.

RESULTS

A marked age-related increase in all typical lesions of age-related maculopathy and macular degeneration was observed. End-stage age-related macular degeneration was present in 1.9% of the population, rising from 0% among people younger than 55 years of age to 18.5% among those 85 years of age or older. Soft drusen were found in 13.3% of people, with distinct drusen more frequent than indistinct soft drusen. Retinal pigmentary abnormalities were found in 12.6% of people. For end-stage lesions and soft drusen, females had higher age-specific prevalence rates than males, whereas retinal pigmentary abnormalities were more frequent in males, although most of these differences were not significant. Prevalence rates for all lesions were lower (statistically significant for retinal pigmentary abnormalities and soft drusen) than for the United States Beaver Dam Eye Study which examined a similar population.

CONCLUSIONS

These data provide detailed prevalence rates for most components of ARM in an Australian population and reinforce the Beaver Dam Eye Study findings for the relative age-specific frequency of age-related macular degeneration components.

Mechanisms of age-related macular degeneration

Age-related macular degeneration (AMD), a progressive condition that is untreatable in up to 90% of patients, is a leading cause of blindness in the elderly worldwide. The two forms of AMD, wet and dry, are classified based on the presence or absence of blood vessels that have disruptively invaded the retina, respectively. A detailed understanding of the molecular mechanisms underlying wet AMD has led to several robust FDA-approved therapies. In contrast, there are no approved treatments for dry AMD. In this review, we provide insight into the critical effector pathways mediating each form of the disease. A recurring theme that spans most aspects of AMD pathogenesis is defective immune modulation in the classically immune-privileged ocular haven. Interestingly, the latest advances in AMD research also highlight common molecular disease pathways with other neurodegenerative disorders. Finally, the therapeutic potential of intervening at known mechanistic steps of AMD pathogenesis is discussed.

Risk factors for age-related macular degeneration: Pooled findings from three continents

OBJECTIVE

To assess the prevalence and potential risk factors for late age-related macular degeneration (AMD) in three racially similar populations from North America, Europe, and AUSTRALIA:

DESIGN

Combined analysis of population-based eye disease prevalence data.

PARTICIPANTS

There were 14,752 participants with gradable photographs from the Beaver Dam Eye Study (n = 4756), Rotterdam Study (n = 6411), and Blue Mountains Eye Study (n = 3585).

MAIN OUTCOME MEASURES

AMD diagnosis was made from masked grading of stereo macular photographs. Final classification of AMD cases was agreed by consensus between study investigators.

RESULTS

AMD prevalence was strongly age related. Overall, AMD was present in 0.2% of the combined population aged 55 to 64 years, rising to 13% of the population older than 85 years. Prevalence of neovascular AMD (NV) increased from 0.17% among subjects aged 55 to 64 years to 5.8% for those older than 85 years. Prevalence of pure geographic atrophy (GA) increased from 0.04% to 4.2% for these age groups. There were no significant gender differences in the prevalence of NV or GA. Subjects in the Rotterdam population had a significantly lower age-adjusted and smoking-adjusted risk of NV than subjects in the Beaver Dam and Blue Mountains populations. Apart from age, tobacco smoking was the only risk factor consistently associated with any form of AMD in all sites separately and in pooled analyses over the three sites.

CONCLUSIONS

These combined data from racially similar communities across three continents provide strong and consistent evidence that tobacco smoking is the principal known preventable exposure associated with any form of AMD.

The epidemiology of age-related macular degeneration

PURPOSE

To review the epidemiology of age-related macular degeneration (AMD).

DESIGN

Evidence from epidemiologic data regarding the natural history of AMD and its risk factors are presented.

RESULTS

Large, soft drusen associated with pigmentary abnormalities increase the risk of progression to advanced AMD. Large soft drusen may fade over time. Advanced AMD is more likely to be present in whites than blacks, despite the similar prevalence of soft drusen in both groups. Neovascular AMD is more frequent than geographic atrophy in most population-based studies in whites in America, Australia, and the Netherlands than in similar population-based studies in Iceland and Norway. After age and family history, there are few consistent relationships of risk factors to AMD. Of these, the relationship of smoking, hypertension, and cataract surgery to advanced AMD have been most consistent.

CONCLUSIONS

Long-term epidemiologic studies have provided information on the distribution and the natural history of AMD and its associated risk factors. It is not known what effect reduction of blood pressure and the cessation of smoking might have on the incidence and progression of AMD.

Age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of legal blindness in the industrialized world. AMD is characterized by accumulation of extracellular deposits, namely drusen, along with progressive degeneration of photoreceptors and adjacent tissues. AMD is a multifactorial disease encompassing a complex interplay between ageing, environmental risk factors and genetic susceptibility. Chronic inflammation, lipid deposition, oxidative stress and impaired extracellular matrix maintenance are strongly implicated in AMD pathogenesis. However, the exact interactions of pathophysiological events that culminate in drusen formation and the associated degeneration processes remain to be elucidated. Despite tremendous advances in clinical care and in unravelling pathophysiological mechanisms, the unmet medical need related to AMD remains substantial. Although there have been major breakthroughs in the treatment of exudative AMD, no efficacious treatment is yet available to prevent progressive irreversible photoreceptor degeneration, which leads to central vision loss. Compelling progress in high-resolution retinal imaging has enabled refined phenotyping of AMD in vivo. These insights, in combination with clinicopathological and genetic correlations, have underscored the heterogeneity of AMD. Hence, our current understanding promotes the view that AMD represents a disease spectrum comprising distinct phenotypes with different mechanisms of pathogenesis. Hence, tailoring therapeutics to specific phenotypes and stages may, in the future, be the key to preventing irreversible vision loss.

Risk factors associated with age-related macular degeneration. A case-control study in the age-related eye disease study: Age-Related Eye Disease Study Report Number 3

OBJECTIVE

To investigate possible risk factors for age-related macular degeneration (AMD) in participants in the Age-Related Eye Disease Study (AREDS).

DESIGN

Case-control study.

PARTICIPANTS

Of the 4757 persons enrolled in AREDS, 4519 persons aged 60 to 80 years were included in this study. The lesions associated with AMD ranged from absent in both eyes to advanced in one eye.

MAIN OUTCOME MEASURES

Stereoscopic color fundus photographs of the macula were used to place participants into one of five groups, based on the frequency and severity of lesions associated with AMD. Participants with fewer than 15 small drusen served as the control group.

RESULTS

Staged model building techniques were used to compare each of the four case groups with the control group. Increased age was a consistent finding of all four of the case groups compared with the control group, and all the following associations were age adjusted. Persons with either intermediate drusen, extensive small drusen, or the pigment abnormalities associated with AMD (group 2) were more likely to be female, more likely to have a history of arthritis, and less likely to have a history of angina. Persons with one or more large drusen or extensive intermediate drusen (group 3) were more likely to use hydrochlorothiazide diuretics and more likely to have arthritis. Hypertension, hyperopia, presence of lens opacities, and white race were also found more frequently in this group as well as in persons with neovascular AMD (group 5). Only persons in group 5 were more likely to have an increased body mass index, whereas persons with geographic atrophy (group 4) as well as those in groups 3 and 5 were more likely to have completed fewer years in school or to be smokers. Those with geographic atrophy were also more likely to use thyroid hormones and antacids.

CONCLUSIONS

Our findings for smoking and hypertension, which have been noted in previous studies, suggest that two important public health recommendations, the avoidance of smoking and the prevention of hypertension, may reduce the risk of developing AMD. Other associations, such as those for hyperopia, lens opacities, less education, female gender, increased body mass index, and white race, which have been noted in other studies, are also seen in the AREDS population. The increased use of thyroid hormones and antacids in persons with geographic atrophy and the increased likelihood of arthritis or hydrochlorothiazide use in persons with one or more large drusen or extensive intermediate drusen have not been previously reported and need additional investigation.

The Wisconsin epidemiologic study of diabetic retinopathy. IV. Diabetic macular edema

The prevalence of macular edema and its relationship to a number of risk factors were examined in a population-based study in southern Wisconsin. Macular edema was determined from its presence on stereoscopic fundus photographs or from past history as recorded and documented in clinic records and photographs. For participants whose age at diagnosis of diabetes was less than 30 years and who were taking insulin (n = 919), prevalence rates of macular edema varied from 0% in those who had diabetes less than 5 years to 29% in those whose duration of diabetes was 20 or more years. In these persons, macular edema was associated with longer duration of diabetes, presence of proteinuria, diuretic use, male gender and higher glycosylated hemoglobin. For those whose age at diagnosis was 30 years or older (n = 1121), prevalence rates of macular edema varied from 3% in those who had diabetes less than 5 years to 28% in those whose duration of diabetes was 20 or more years. In these persons, presence of macular edema was associated with longer duration of diabetes, higher systolic blood pressure, insulin use, higher glycosylated hemoglobin, and presence of proteinuria.

The prevalence of age-related maculopathy in the Rotterdam Study

PURPOSE

To determine the prevalence of age-related maculopathy in an elderly population in The Netherlands.

METHODS

Fundus photographs of 6251 participants of the Rotterdam Study, a single-center prospective follow-up study in persons 55 to 98 years of age, were reviewed for the presence of drusen, pigmentary abnormalities, and atrophic or neovascular age-related macular degeneration.

RESULTS

The prevalence of at least one drusen of 63 microns or larger increased from 40.8% in persons 55 to 64 years of age to 52.6% in those 85 years of age or older. Similarly, the prevalence of the following abnormalities increased significantly in these age categories: drusen of 125 microns or larger from 4.8% to 17.5%, retinal pigment epithelial hypopigmentations from 3.5% to 9.0%, and increased retinal pigment from 3.7% to 15.3%. Atrophic or neovascular age-related macular degeneration was present in 1.7% of the total population. Atrophic age-related macular degeneration increased from 0.1% in persons 55 to 64 years of age to 3.7% in those 85 years of age or older. Neovascular age-related macular degeneration increased from 0.1% to 7.4% in these age groups. No sex differences were observed for these lesions.

CONCLUSIONS

The prevalence of atrophic or neovascular age-related macular degeneration is 1.7%. In those 55 years of age or older, the prevalence increases strongly with age and it is similar in men and women. Neovascular age-related macular degeneration was twice as common as atrophic age-related macular degeneration. These findings suggest that age-related maculopathy may be less common in this European population than in similar populations in the United States.

The five-year incidence and progression of age-related maculopathy: the Beaver Dam Eye Study

PURPOSE

The aim of the study was to describe the incidence and progression of retinal drusen, retinal pigmentary abnormalities, and signs of late age-related maculopathy.

POPULATION

A population of 3583 adults (range, 43-86 years of age at baseline) living in Beaver Dam, Wisconsin, was studied during a 5-year period.

METHODS

Characteristics of drusen and other lesions typical of age-related maculopathy were determined by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.

RESULTS

There was a statistically significant increased incidence of age-related maculopathy lesions with age (P < 0.05). Individuals 75 years of age or older had a significantly (P < 0.01) higher 5-year incidence of the following characteristics than people 43 to 54 years of age: larger sized drusen (125-249 microm, 17.6% vs. 2.1%; > or = 250 microm, 6.5% vs. 0.2%), soft indistinct drusen (16.3% vs. 1.8%), retinal pigment abnormalities (12.9% vs. 0.9%), exudative macular degeneration (1.8% vs. 0%), and pure geographic atrophy (1.7% vs. 0%). After adjusting for age, the incidence of early age-related maculopathy was 2.2 times (95% confidence interval 1.6, 3.2) as likely in women 75 years of age or older compared with men this age. At follow-up, late age-related macular degeneration was more likely to develop in eyes with soft indistinct drusen (6.5% vs. 0.1%) or retinal pigmentary abnormalities (7.1% vs. 0.1%) at baseline than in eyes without these lesions.

CONCLUSIONS

These population-based estimates document the high incidence of signs of age-related maculopathy in people 75 years of age or older, and in women compared with men that age. The findings demonstrate that the presence of soft drusen and pigmentary abnormalities significantly increases the risk for the development of geographic atrophy and exudative macular degeneration.

Age-related macular degeneration--emerging pathogenetic and therapeutic concepts

Today, the average life expectancy in developed nations is over 80 years and climbing. And yet, the quality of life during those additional years is often significantly diminished by the effects of age-related, degenerative diseases, including age-related macular degeneration (AMD), the leading cause of blindness in the elderly worldwide. AMD is characterized by a progressive loss of central vision attributable to degenerative and neovascular changes in the macula, a highly specialized region of the ocular retina responsible for fine visual acuity. Estimates gathered from the most recent World Health Organization (WHO) global eye disease survey conservatively indicate that 14 million persons are blind or severely visually impaired because of AMD. The disease has a tremendous impact on the physical and mental health of the geriatric population and their families and is becoming a major public health burden. Currently, there is neither a cure nor a means to prevent AMD. Palliative treatment options for the less prevalent, late-stage 'wet' form of the disease include anti-neovascular agents, photodynamic therapy and thermal laser. There are no current therapies for the more common 'dry' AMD, except for the use of antioxidants that delay progression in 20%-25% of eyes. New discoveries, however, are beginning to provide a much clearer picture of the relevant cellular events, genetic factors, and biochemical processes associated with early AMD. Recently, compelling evidence has emerged that the innate immune system and, more specifically, uncontrolled regulation of the complement alternative pathway plays a central role in the pathobiology of AMD. The complement Factor H gene--which encodes the major inhibitor of the complement alternative pathway--is the first gene identified in multiple independent studies that confers a significant genetic risk for the development of AMD. The emergence of this new paradigm of AMD pathogenesis should hasten the development of novel diagnostic and therapeutic approaches for this disease that will dramatically improve the quality of our prolonged lifespan.

Risk factors for the incidence of Advanced Age-Related Macular Degeneration in the Age-Related Eye Disease Study (AREDS) AREDS report no. 19

PURPOSE

To describe the association of demographic, behavioral, medical, and nonretinal ocular factors with the incidence of neovascular age-related macular degeneration (AMD) and central geographic atrophy (CGA) in the Age-Related Eye Disease Study (AREDS), a randomized trial of antioxidants and zinc supplementation prophylaxis for development of advanced AMD.

DESIGN

Clinic-based prospective cohort study.

PARTICIPANTS

Of individuals with early or intermediate AMD at baseline with a median follow-up of 6.3 years, 788 were at risk of developing advanced AMD in one eye (the fellow eye had advanced AMD), and 2506 were at risk in both eyes.

METHODS

The incidence of neovascular AMD and CGA was assessed from stereoscopic color fundus photographs taken at baseline and at annual visits beginning at year 2.

MAIN OUTCOME MEASURES

Neovascular AMD was defined as photocoagulation for choroidal neovascularization, or photographic documentation at the reading center of any of the following: nondrusenoid retinal pigment epithelial detachment, serous or hemorrhagic retinal detachment, hemorrhage under the retina or the retinal pigment epithelium, and subretinal fibrosis. Central geographic atrophy was defined as geographic atrophy involving the center of the macula.

RESULTS

In multivariable models, in persons at risk of advanced AMD in both eyes, while controlling for age, gender, and AREDS treatment group, the following variables were statistically significantly associated with the incidence of neovascular AMD: race (odds ratio [OR], white vs. black, 6.77; 95% confidence interval [CI], 1.24-36.9) and larger amount smoked (OR, >10 vs. < or =10 pack-years [a pack-year is an average of 1 pack of cigarette smoked per day for a year], 1.55; 95% CI, 1.15-2.09). The following were statistically significantly associated with the incidence of CGA: less education (OR, high school graduate or less vs. college graduate, 1.75; 95% CI, 1.10-2.78), greater body mass index (BMI) (OR, obese vs. nonobese, 1.93; 95% CI, 1.25-2.65), larger amount smoked (OR, >10 pack-years vs. < or =10 pack-years, 1.82; 95% CI, 1.25-2.65), and antacid use (OR, 0.29; 95% CI, 0.09-0.91). In persons at risk of developing advanced AMD in one eye, the incidence of neovascular AMD was associated with diabetes (OR, 1.88; 95% CI, 1.07-3.31), and the incidence of CGA was associated with use of antiinflammatory medications (OR, 0.22; 95% CI, 0.08-0.59).

CONCLUSIONS

Results suggest that, among persons with early or intermediate AMD, smoking and BMI are modifiable factors associated with progression to advanced AMD, and suggest other associations (e.g., use of antacids and antiinflammatory medications) that warrant further study. This article contains additional online-only material available at http://www.ophsource.org/periodicals/ophtha. .

Fifteen-Year Cumulative Incidence of Age-Related Macular Degeneration

PURPOSE

To describe the 15-year cumulative incidence of signs of early and late age-related macular degeneration (AMD).

DESIGN

Population-based cohort study.

PARTICIPANTS

We included 3917 persons, 43 to 86 years of age at the time of a baseline examination in 1988 through 1990 and with information collected in follow-up in 1993 through 1995, and/or 1998 through 2000, and/or 2003 through 2005.

METHODS

Grading of stereoscopic fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.

MAIN OUTCOME MEASURES

Cumulative incidence of drusen type and size, pigmentary abnormalities, geographic atrophy, and exudative AMD accounting for competing risk of death.

RESULTS

The 15-year cumulative incidence was 14.3% for early AMD (the presence of either soft indistinct drusen or the presence of pigmentary abnormalities together with any type of drusen) and 3.1% for late AMD (presence of exudative AMD or geographic atrophy). There was an increased incidence of AMD lesions with age (P<0.05). Individuals > or = 75 years of age at baseline had significantly (P<0.01) higher 15-year incidences of the following characteristics than people 43 to 54 years of age: larger drusen (125 mum in diameter, 24.1% vs 10.6%), soft indistinct drusen (18.7% vs 6.5%), retinal pigmentary abnormalities (20.2% vs 3.7%), exudative macular degeneration (4.4% vs 0.4%), and pure geographic atrophy (3.2% vs 0%). Controlling for age, compared with those with small numbers of only small hard drusen (1-2), those with large numbers of only hard drusen (> or =8) had an increased 15-year age-adjusted incidence of both soft indistinct drusen (16.3% vs 4.7%) and pigmentary abnormalities (10.6% vs 2.7%). Eyes with soft indistinct drusen or pigmentary abnormalities at baseline were more likely to develop late AMD at follow-up than eyes without these lesions (17.8% vs 1.2% and 12.9% vs 1.7%, respectively).

CONCLUSIONS

We document the long-term incidence of signs of AMD and a continuum from small hard drusen to late AMD in older persons in the population. The 15-year cumulative incidence of late AMD in people > or = 75 years of age (8%) indicates a public health problem of significant proportions because the United States population this age is expected to increase by 54% between 2005 and 2025.

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.

Risk factors for neovascular age-related macular degeneration. The Eye Disease Case-Control Study Group

Neovascular age-related macular degeneration (AMD) is one of five retinal disorders studied in the Eye Disease Case-Control Study. Data were obtained from 421 patients with neovascular AMD and 615 controls on a broad array of possible risk factors through interviews, clinical examinations, and laboratory analyses of blood samples. Decreased risk of neovascular AMD was associated with higher levels of carotenoids in the serum samples, higher horizontal cup-to-disc ratios, and use of postmenopausal exogenous estrogens in women. Increased risk of neovascular AMD was associated with cigarette smoking, higher levels of serum cholesterol, and parity greater than zero. No support was found for sunlight exposure, serum zinc levels, or iris color as risk factors for this disease. Although no association was found with a history of cardiovascular disease itself, the associations with postmenopausal exogenous estrogen use, cigarette smoking, and serum cholesterol level are consistent with a hypothesis linking risk factors for cardiovascular disease with neovascular AMD. The association noted between serum carotenoid levels and neovascular AMD supports the hypothesis that higher levels of micronutrients with antioxidant capabilities may decrease the risk of AMD.

The Framingham Eye Study. I. Outline and major prevalence findings

During the period 1973--1975, 2675 out of 3977 still-living members of the Framingham, Massachusetts, study population, who have been under investigation for coronary disease risk factors since 1948 and who were in 1973--1975 aged 52 to 85, were given an eye examination stressing cataract, diabetic retinopathy, macular degeneration and glaucoma. Of 2940 subjects who still lived in the local Framingham area, 2477 were examined. Local population prevalence for one or both eyes positive was: 15.5% for senile cataract, 3.1% for diabetic retinopathy, 8.8% for senile macular degeneration and 3.3% for open-angle glaucoma. The proportion of adults with poor "best" visual acuity may be much less than has been estimated by the National Health Survey and the proportion with open-angle glaucoma much more than currently suspected on the basis of foreign studies.

Depression, visual acuity, comorbidity, and disability associated with age-related macular degeneration

OBJECTIVE

To examine (1) the prevalence of depressive disorders in community-dwelling adults with advanced age-related macular degeneration (AMD) and (2) the relationship in this population between depression, visual acuity, the number of comorbid medical conditions, disability caused by vision loss as measured by the National Eye Institute-Vision Function Questionnaire (NEI-VFQ) and the vision-specific Sickness Impact Profile (SIPV), and disability caused by overall health status as measured by the Sickness Impact Profile-68 (SIP).

DESIGN

Analysis of cross-sectional baseline data from a randomized clinical trial.

PARTICIPANTS

Participants were 151 adults aged 60 and older (mean age, 80 years) with advanced macular degeneration whose vision was 20/60 or worse in their better eye.

METHODS

Subjects were interviewed using measures of depression, disability, and chronic medical conditions. Visual acuity was obtained. Nonparametric correlation analyses and linear regression analyses were performed.

MAIN OUTCOME MEASURES

Structured Clinical Interview for DSM-IV (SCID-IV), Geriatric Depression Scale (GDS), NEI-VFQ, SIPV, and SIP.

RESULTS

Of the participants, 32.5% (n = 49) met SCID-IV criteria for depressive disorder, twice the rate observed in previous studies of community-dwelling elderly. Over and above depression (GDS), visual acuity aided in prediction of the level of vision-specific disability (NEI-VFQ and SIPV).

CONCLUSIONS

Depressive disorder is a significant problem for the elderly afflicted with advanced macular degeneration. Further research on psychopharmacologic and psychotherapeutic interventions for depressed AMD patients is warranted to improve depression and enhance functioning. Over and above depression, visual acuity aided in predicting vision-specific disability. Treatment strategies that teach patients to cope with vision loss should be developed and evaluated.

Smoking and age-related macular degeneration: a review of association

PURPOSE

Age-related macular degeneration (AMD) is the leading cause of severe and irreversible vision loss in the Western world. As there is no effective treatment for all types of AMD, identifying modifiable risk factors is of great importance. This review evaluates the epidemiological evidence associating smoking with AMD.

METHODS

Systematic review of published epidemiological studies evaluated against established criteria for evidence of a causal relationship.

RESULTS

In total, 17 studies (cross-sectional studies, prospective cohort studies, and case-control studies) were included in the review. A total of 13 studies found a statistically significant association between smoking and AMD with increased risk of AMD of two- to three-fold in current-smokers compared with never-smokers. Five studies found no association between smoking and AMD. There was also evidence of dose-response, a temporal relationship and reversibility of effect.

CONCLUSION

The literature review confirmed a strong association between current smoking and AMD, which fulfilled established causality criteria. Cigarette smoking is likely to have toxic effects on the retina. In spite of the strength of this evidence, there appears to be a lack of awareness about the risks of developing eye disease from smoking among both healthcare professionals and the general public.

Ten-year incidence and progression of age-related maculopathy: The Beaver Dam eye study

PURPOSE

The aim of the study was to describe the 10-year incidence and progression of retinal drusen, retinal pigmentary abnormalities, and signs of late age-related maculopathy.

DESIGN

Population-based cohort study.

PARTICIPANTS

The study included 4926 persons, 43 to 86 years of age at the time of a baseline examination from 1988 through 1990, living in Beaver Dam, Wisconsin, of whom 3684 participated in a 5-year follow-up examination and 2764 participated in a 10-year follow-up.

METHODS

Characteristics of drusen and other lesions typical of age-related maculopathy were determined by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.

MAIN OUTCOMES MEASURES

Incidence of drusen type and size, pigmentary abnormalities, geographic atrophy, and exudative degeneration.

RESULTS

The 10-year incidence of early age-related maculopathy was 12.1% and of late age-related maculopathy it was 2.1%. There was a statistically significant increased incidence of age-related maculopathy lesions with age (P < 0.05). Individuals 75 years of age or older at baseline had significantly (P < 0.01) higher 10-year incidences of the following characteristics than people 43 to 54 years of age: larger sized drusen (125 micro m-249 micro m, 26.3% vs. 3.3%; > or =250 micro m, 16.2% vs. 1.0%), soft indistinct drusen (22.2% vs. 2.2%), retinal pigment abnormalities (19.5% vs. 0.8%), exudative macular degeneration (4.1% vs. 0%), and pure geographic atrophy (3.1% vs. 0%). Compared with those with small numbers of only small, hard drusen (1-2), those with large numbers of only hard drusen (8 or more) had an increased 10-year incidence of both soft drusen (12.3% vs. 6.7%) and pigmentary abnormalities (4.9% vs. 1.7%). Eyes with soft indistinct drusen or retinal pigmentary abnormalities at baseline, were more likely to develop late age-related macular degeneration at follow-up than eyes without these lesions (15.1% vs. 0.4% and 20.0% vs. 0.8%, respectively).

CONCLUSIONS

These population-based estimates document the high incidence of signs of age-related maculopathy in people 75 years of age or older. Our findings demonstrate that large numbers of hard drusen predict the incidence of soft drusen and pigmentary abnormalities and that the presence of the latter lesions significantly increases the risk for the development of geographic atrophy and exudative macular degeneration.

The long-term effects of visible light on the eye

The relationship between exposure to sunlight and senile cataract, age-related macular degeneration, pterygium, and climatic droplet keratopathy was examined in 838 watermen who work on the Chesapeake Bay. The presence and severity of lenticular, corneal, and macular changes were assessed by either clinical examination or from stereo macular photographs. From detailed exposure histories, ocular exposure was estimated for three bands of visible radiation-violet (400 to 450 nm), blue (400 to 500 nm), or all visible (400 to 700 nm)-as well as for UV-A (320 to 340 nm) and UV-B (290 to 320 nm). The results with each band of visible radiation were similar. Neither cortical nor nuclear cataract was associated with ocular exposure to blue or all visible radiation, but pterygium and climatic droplet keratopathy were more common with higher exposures. Compared with age-matched controls, patients with advanced age-related macular degeneration (geographic atrophy or disciform scarring) had significantly higher exposure to blue or visible light over the preceding 20 years (odds ratio, 1.36 [1.00 to 1.85]) but were not different in respect to exposure to UV-A or UV-B. These data suggest that high levels of exposure to blue or visible light may cause ocular damage, especially later in life, and may be related to the development of age-related macular degeneration.