Smoking and the 5-year incidence of age-related maculopathy: the Blue Mountains Eye Study

Transplantation of the RPE in AMD

The retinal pigment epithelium (RPE) maintains retinal function as the metabolic gatekeeper between photoreceptors (PRs) and the choriocapillaries. The RPE and Bruch's membrane (BM) suffer cumulative damage over lifetime, which is thought to induce age-related macular degeneration (AMD) in susceptible individuals. Unlike palliative pharmacologic treatments, replacement of the RPE has a curative potential for AMD. This article reviews mechanisms leading to RPE dysfunction in aging and AMD, laboratory studies on RPE transplantation, and surgical techniques used in AMD patients. Future strategies using ex vivo steps prior to transplantation, BM prosthetics, and stem cell applications are discussed. The functional peculiarity of the macular region, epigenetic phenomena leading to an age-related shift in protein expression, along with the accumulation of lipofuscin may affect the metabolism in the central RPE. Thickening of BM with age decreases its hydraulic conductivity. Drusen are deposits of extracellular material and formed in part by activation of the alternative complement pathway in individuals carrying a mutant allele of complement factor H. AMD likely represents an umbrella term for a disease entity with multifactorial etiology and manifestations. Presently, a slow progressing (dry) non-neovascular atrophic form and a rapidly blinding neovascular (wet) form are discerned. No therapy is currently available for the former, while RPE transplantation and promising (albeit non-causal) anti-angiogenic therapies are available for the latter. The potential of RPE transplantation was demonstrated in animal models. Rejection of allogeneic homologous transplants in patients focused further studies on autologous sources. In vitro studies elucidated cell adhesion and wound healing mechanisms on aged human BM. Currently, autologous RPE, harvested from the midperiphery, is being transplanted as a cell suspension or a patch of RPE and choroid in AMD patients. These techniques have been evaluated from several groups. Autologous RPE transplants may have the disadvantage of carrying the same genetic information that may have led to AMD manifestation. An intermittent culturing step would allow for in vitro therapy of the RPE, its rejuvenation and prosthesis of BM to improve the success RPE transplants. Recent advances in stem cell biology when combined with lessons learned from studies of RPE transplantation are intriguing future therapeutic modalities for AMD patients.

Effect of pitavastatin on experimental choroidal neovascularization in rats

The association between the use of statins and age-related macular degeneration (AMD), a leading cause of blindness, has been evaluated in many clinical studies; however, the results have been contradictory. We evaluated the effect of pitavastatin administration on laser-induced experimental choroidal neovascularization (CNV) in rats. Brown Norway rats received pitavastatin (1.0mg/kg per day) for 1day prior to laser-induced CNV and continued to receive the drug for 14days. Fluorescein angiograms were graded by masked observers. CNV area and thickness were assessed by fluorescein isothiocyanate-labeled dextran angiography and histology, respectively. Vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (Ccl-2; also known as MCP-1), and intercellular adhesion molecule-1 (ICAM-1) mRNA levels were measured using reverse-transcription polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR. Pitavastatin-treated rats had significantly less fluorescence leakage compared with the vehicle-treated rats estimated by CNV score using fluorescein angiography. Both the area and the thickness of CNV in pitavastatin-treated rats were significantly reduced compared with the vehicle-treated rats. Gene expression of VEGF, Ccl-2, and ICAM-1 were significantly decreased by pitavastatin administration in experimental CNV. Thus, we demonstrated that the therapeutic dose of pitavastatin for human hypocholesterolemia effectively suppressed experimental CNV in rats. The use of pitavastatin may be helpful in preventing CNV development in AMD patients.

Influence of macular pigment and melanin on incident early AMD in a white population

BACKGROUND

The protective effect of macular pigment (MP) and melanin against age-related macular degeneration (AMD) is still controversial from cross-sectional studies. In an attempt to clarify this issue, we performed a population-based longitudinal study.

METHODS

MP optical density (MPOD) and melanin optical density (MOD) data were collected during the second follow-up phase of the Rotterdam Study in 1999 in a random subset of 435 participants. Data from 419 participants (98% white) was available for analysis. AMD diagnosis was based on standardized fundus photographs according to the International Classification System, and AMD cases were subdivided into five mutually exclusive stages. In the three follow-up phases, incident AMD (iAMD), defined as absence of any AMD at baseline and the presence of stage 2 or higher at follow-up, was determined. We used Cox regression analysis to study the effect of an assumedly stable MPOD and MOD on early iAMD.

RESULTS

During a mean follow-up of 9.82 years, 13 male and 17 female participants developed early iAMD and two male participants late iAMD. Because only two participants developed late iAMD, we had to restrict our analyses to early iAMD. Cox regression analysis adjusted for age and gender showed no significant effect of MPOD [hazard ratio (HR) 0.37; 95% confidence interval (CI) 0.04, 3.57] and MOD (HR 0.56; 95% CI 0.09, 3.60) on early iAMD. Additional adjustment for smoking did not change these associations.

CONCLUSIONS

This unique but quantitatively limited material leads to the conclusion that no major protective effect of MPOD or MOD was seen on early iAMD.

Treatment of nonexudative (dry) age-related macular degeneration

PURPOSE OF REVIEW

The purpose of this report is to review the recent literature and summarize currently available and potential new treatment options for nonexudative age-related macular degeneration.

RECENT FINDINGS

High-dose vitamin supplementation may have some associated systemic toxicity. It is important to check that the patient is taking beta-carotene and not vitamin A as retinal acetate or palmitate, which have been associated with osteoporosis and hepatotoxicity. High-dose vitamins E and C may be associated with cardiovascular disease. Decreasing inflammation by lowering systemic cardiac C-reactive protein, fibrinogen and cholesterol may be important, especially in light of recent epidemiologic and genetic data. The results of randomized trials of laser treatment for drusen and rheopheresis should be available during 2006. Treatment with these modalities before the results of the trials are evaluated should be avoided.

SUMMARY

The holy grail of therapy for age-related macular degeneration is to avoid the development of choroidal neovascularization. High-dose vitamin supplementation should be used only in those in whom it is indicated and inflammatory parameters including highly sensitive C-reactive protein, fibrinogen and cholesterol should be stabilized because there are data associating these parameters with age-related macular degeneration and also with cardiovascular disease.

Functional loss in early age-related maculopathy: the ischaemia postreceptoral hypothesis

We review proposed models and psychophysical and electrophysiological tests performed in many studies for early age-related maculopathy (ARM). We suggest that ischaemia is the trigger for impaired retinal pigment epithelium function causing imbalance of secretion of vascular growth factors, reduced disc degradation capability and reduced metabolic activity and possible inflammatory response. This results in increased deposition of cell debris, such as drusen and thickens Bruch's membrane causing even more ischaemia of the overlying neurosensory retina. The photoreceptors are more resistant to ischaemia given their proximity to the choroid. Furthermore, being 'upstream' from the inner retinal layers, they act as an oxygen sink depriving retinal layers further from the choroid. Postreceptoral cell layers and especially parts of the inner nuclear layer that are located in the watershed zone between two sources of blood supply are preferentially vulnerable to ischaemia. Based on psychophysical and electrophysiological findings we propose that most of the function impairment in early ARM starts postreceptorally.

Analogies entre processus athéromateux et dégénérescence maculaire liée à l’âge : rôles présumés des oxystérols

The pathogenesis of age-related macular degeneration (ARMD) is not clearly understood. Like other age-related diseases, it is associated with abnormal deposits called drusen. These drusens are localized in Bruch's membrane. Recent investigations have shown a link between drusen formation and inflammatory and immunologic reactions. The involvement of oxidative stress is supported by available data as an important contributing factor in the developement of ARMD. The data regarding the nature and the source of the deposits suggest that ARMD may share similar pathways with atherosclerosis. The role of oxydized products of cholesterol, the oxysterols, in the pathogenesis of atherosclerosis is well known. As cholesterol is a constituent of drusens, oxysterols could be involved in retinal pigment epithelium and photoreceptor lesions occurring in ARMD owing to their cytotoxic, pro-inflammatory, and pro-oxydant properties.

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.

Antiangiogenic therapy with interferon alfa for neovascular age-related macular degeneration

BACKGROUND

Antiangiogenic therapy is a new approach to the treatment of neovascular age-related macular degeneration. Interferon alfa is one antiangiogenic agent thought to function by inhibiting the migration and proliferation of vascular endothelial cells. It has been used in the treatment of hepatitis, solid tumors and hematologic malignancies.

OBJECTIVES

The aim of this review was to investigate interferon alfa as a treatment modality for neovascular age-related macular degeneration.

SEARCH STRATEGY

We searched and identified trials from the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Group Trials Register, in The Cochrane Library (Issue 2, 2005), MEDLINE (1966 to 2005/06 week 1), EMBASE (1980 to 2005/week 23), LILACS (Latin American and Caribbean Health Science Literature Database) (June 2005) and the reference lists of included studies.

SELECTION CRITERIA

This review included randomized controlled trials evaluating interferon alfa therapy in people with neovascular age-related macular degeneration who were followed for at least one year.

DATA COLLECTION AND ANALYSIS

Both review authors independently extracted data and assessed trial quality. No data synthesis was conducted as only one trial met the inclusion criteria.

MAIN RESULTS

The one included trial enrolled and randomized 481 participants from 45 centers worldwide into four groups. The study allowed for analysis of the number of participants who had lost three or more lines of vision at 52 weeks in three interferon alfa-2a groups versus placebo. The results show an odds ratio of 1.60 (95% Confidence Interval 1.01 to 2.53) indicating that interferon is associated with a 60% increased odds of losing three or more lines at 52 weeks. This finding is marginally statistical with a P value of 0.04 and indicates that the treatment has the potential for harm rather than benefit.

AUTHORS' CONCLUSIONS

At present there is not enough evidence to recommend the use of interferon alfa-2a for the treatment of age-related macular degeneration.

[Association between classic cardiovascular risk factors and age-related maculopathy (ARM). Results of the baseline examination of the Münster Aging and Retina Study (MARS)]

BACKGROUND

Epidemiological studies have reported inconsistent associations between cardiovascular risk factors and the occurrence of age-related maculopathy (ARM).

METHODS

In the baseline examination of the Muenster Aging and Retina Study (MARS), we assessed this potential relationship in 1060 subjects who underwent clinical and ophthalmologic examinations. The ARM status was graded according to international standardized classifications.

RESULTS

There were 974 eye pairs available for analysis. Smoking, hypertension, hypercholesterolemia, and a history of myocardial infarction or stroke were found significantly more often in patients with ARM. There were no statistically significant multivariate associations between overweight, diabetes, or a history of myocardial infarction or stroke.

CONCLUSIONS

Our results confirm previous epidemiological studies pointing to a potential role of atherosclerotic processes in the development of ARM.

Smoking, alcohol intake, estrogen use, and age-related macular degeneration in Latinos: the Los Angeles Latino Eye Study

PURPOSE

To assess the association between smoking, alcohol intake, estrogen use, and both early age-related macular degeneration (AMD) (soft indistinct drusen, retinal pigment abnormalities) and advanced AMD (exudative AMD, geographic atrophy) in the Latino community.

DESIGN

Population-based, cross-sectional study.

METHODS

Complete ophthalmic examination included stereoscopic macular photographs graded with a modified Wisconsin Age-related Maculopathy Grading System. A history of smoking, alcohol intake, and exogenous estrogen use was obtained by interview. Logistic regression was performed, and odds ratios (OR) were calculated with each AMD lesion as a dependent variable.

RESULTS

There were 5875 participants (92.4%) with gradable photographs. Having ever smoked was associated with a higher risk of having advanced AMD (OR, 2.4). Heavy consumption of alcohol (>5 drinks per session) was significantly associated with a greater risk of having exudative AMD (OR, 5.8) and geographic atrophy (OR, 12.7) Beer drinking was associated with a higher risk of having advanced AMD (OR, 2.9), whereas wine drinking appeared to be protective for increased retinal pigment (OR, 0.7). Exogenous estrogen use also appeared to be protective from soft indistinct drusen (OR, 0.5) and increased retinal pigment (OR, 0.6), but power was limited in the assessment of its association with advanced AMD.

CONCLUSION

Smoking and heavy alcohol consumption, particularly beer, was associated with a greater risk of having advanced AMD; exogenous estrogen use appeared to have a weak protective effect in Latino participants. Similar modifiable risk factors have been identified previously in non-Hispanic white patients, which suggests that common pathogenic mechanisms may be associated with AMD in persons of different ethnicities.

28,000 Cases of age related macular degeneration causing visual loss in people aged 75 years and above in the United Kingdom may be attributable to smoking

BACKGROUND

Age related macular degeneration (AMD) causing visual impairment is common in older people. Previous studies have identified smoking as a risk factor for AMD. However, there is limited information for the older population in Britain.

METHODS

Population based cross sectional analytical study based in 49 practices selected to be representative of the population of Britain. Cases were people aged 75 years and above who were visually impaired (binocular acuity <6/18) as a result of AMD. Controls were people with normal vision (6/6 or better). Smoking history was ascertained using an interviewer administered questionnaire.

RESULTS

After controlling for potentially confounding factors, current smokers were twice as likely to have AMD compared to non-smokers (odds ratio 2.15, 95% CI 1.42 to 3.26). Ex-smokers were at intermediate risk (odds ratio 1.13, 0.86 to 1.47). People who stopped smoking more than 20 years previously were not at increased risk of AMD causing visual loss. Approximately 28,000 cases of AMD in older people in the United Kingdom may be attributable to smoking.

CONCLUSION

This is the largest study of the association of smoking and AMD in the British population. Smoking is associated with a twofold increased risk of developing AMD. An increased risk of AMD, which is the most commonly occurring cause of blindness in the United Kingdom, is yet another reason for people to stop smoking and governments to develop public health campaigns against this hazard.

HMG CoA reductase inhibitors (statins): do they have a role in age-related macular degeneration?

Age-related macular degeneration is a progressive late onset disease affecting central vision. It is the leading cause of irreversible blindness in developed countries, and with the aging population the problem is increasing. Current treatment options are limited to the late stage of the disease when central vision is already under great threat, and even new treatments make little impact on the rate of blindness. Intervention earlier in the disease may prove more rewarding, but to date little progress has been made with this approach. Epidemiologic, genetic, and pathological evidence continues to accumulate, suggesting a possible link between risk factors for cardiovascular diseases and age-related macular degeneration. This article reviews the evidence and discusses the rationale behind the recent suggestions that cholesterol-lowering agents may be useful in the treatment of early age-related macular degeneration. The cholesterol-lowering family of drugs called statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) inhibitors with pleiotropic actions. Their therapeutic effects in cardiovascular disease and dyslipidaemia have been well proven. In this review we will outline the known actions of statins and discuss possible ways that they may impact on age-related macular degeneration.

MELAS A3243G mitochondrial DNA mutation and age related maculopathy

PURPOSE

To determine whether mitochondrial DNA mutations play a role in the development of age related maculopathy (ARM).

DESIGN

Case report.

METHODS

Hair follicles were collected from 3557 persons aged 49 years or older during the Blue Mountains Eye Study. General health measures were assessed and a detailed eye examination was performed, including stereo retinal photography of the macula, and other retinal fields. ARM was graded according to international classification. Polymerase chain reaction and restriction fragment length polymorphism analysis was performed to detect the MELAS A3243G mutation in 570 subjects identified to have signs of Early or Late ARM, as well as in age- and gender-matched controls.

RESULTS

Only one participant with Early ARM, mild hearing loss, hypertension, ischemic heart disease, and asthma was found to have the MELAS A3243G mutation.

CONCLUSIONS

The MELAS A3243G mutation appears to be a very rare cause of typical ARM in the general population.

Cost utility of photodynamic therapy for predominantly classic neovascular age related macular degeneration

BACKGROUND/AIM

Age related macular degeneration (AMD) is the leading cause of severe vision impairment and blindness in older people throughout the developed world and currently affects around 420 000 UK citizens. Choroidal neovascularisation (CNV) is treatable with photodynamic therapy (PDT) but is expensive at over pound 1200 per treatment. The aim of this study was to assess the cost utility of PDT for better eye, predominantly classic, subfoveal choroidal neovascular lesions secondary to AMD.

METHODS

Cost utility analysis (CUA) was conducted to estimate the cost effectiveness of PDT for scenarios involving reasonable (6/12) and poor (6/60) visual acuity. The models incorporated data from the Treatment of Age-related Macular Degeneration with PDT (TAP) Study and patient based utilities. The incremental CUA was based on decision analytical models, comparing treatment to a placebo comparator. Extensive one way sensitivity analysis of parameters was conducted to determine the robustness of the model. A discount rate of 6% was used for costs and quality adjusted life years (QALY).

RESULTS

Model 1: in people with reasonable initial visual acuity, the cost utility of treating applicable neovascular AMD lesions was pound 31 607 per QALY saved, with a sensitivity analysis range from pound 25 285 to pound 37 928. Model 2: in people with poor initial visual acuity, the cost utility was pound 63 214 per QALY saved, with a sensitivity analysis range from pound 54 183 to pound 75 856.

CONCLUSIONS

PDT treatment is the only available treatment for some forms of neovascular ("wet") AMD. Under these assumptions, PDT can be considered moderately cost effective for those with reasonable visual acuity but less cost effective for those with initial poor visual acuity. These findings have implications for ophthalmic practice and healthcare planning.

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.

Lutein, zeaxanthin, macular pigment, and visual function in adult cystic fibrosis patients

BACKGROUND

Pancreatic insufficiency in cystic fibrosis (CF), even with replacement pancreatic enzyme therapy, is often associated with decreased carotenoid absorption. Because the macular pigment of the retina is largely derived from 2 carotenoids, lutein and zeaxanthin, the decreased serum concentrations seen in CF may have consequences for ocular and retinal health

OBJECTIVES

Our aims were to determine plasma carotenoid concentrations, determine absorption and distribution of macular pigment, and assess retinal health and visual function in CF patients.

DESIGN

In 10 adult CF patients (ages 21-47 y) and 10 age- and sex-matched healthy control subjects, we measured macular pigment density in vivo, measured serum lutein and zeaxanthin concentrations, and comprehensively assessed visual performance (including contrast sensitivity, color discrimination, and retinal function) under conditions of daylight illumination.

RESULTS

Serum lutein and zeaxanthin were significantly reduced (P < 0.005) in CF patients ( +/- SD: 87 +/- 36.1 and 27 +/- 15.8 nmol/L, respectively) compared with control subjects (190 +/- 72.1 and 75 +/- 23.6 nmol/L, respectively). Although macular pigment optical density was significantly lower (P < 0.0001) in the CF group (0.24 +/- 0.11) than in the control group (0.53 +/- 0.12), no significant differences in visual function were observed.

CONCLUSIONS

Adults with CF have dramatically low serum and macular concentrations of carotenoids (lutein and zeaxanthin), but their ocular status and visual function are surprisingly good. The clinical implications of low plasma concentrations of carotenoids in CF are yet to be clarified.

Ocular changes, risk markers for eye disorders and effects of cataract surgery in elderly people: a study of an urban Swedish population followed from 70 to 97 years of age

AIMS

To investigate the prevalence of and potential risk factors for ocular disorders and the effects of timing of cataract surgery from age 70-97 years.

POPULATION

A representative population sample taken from within the Gerontological and Geriatric Population Studies (H 70) in Gothenburg, Sweden (n = 958). All subjects underwent eye examinations at age 70 years in 1971 and subsequently at ages 82, 88, 95 and 97 years. All inhabitants of Gothenburg aged 95 and 97 years were invited to participate in the study.

RESULTS

Decreased vision (visual acuity < or = 0.5) was found in 20% and 80% of subjects at ages 82 and 97 years, respectively. Blood folate and physical activity at age 70 years correlated positively and body mass index (BMI) negatively to visual acuity (VA) > or = 0.8 at ages 82 and 88 years. Smoking at age 70 years correlated to early age-related maculopathy (ARM). Cataract surgery had been performed in 40% of subjects at age 97 years. Surgery 2 years earlier led to a 15% increase in time spent with improved vision.

CONCLUSIONS

The deterioration of vision in elderly people is a major health problem, for which 'low' folate status, smoking, 'high' BMI and low physical activity are potential risk factors. Early cataract surgery is also beneficial in very old patients.

Cost utility of screening and treatment for early age related macular degeneration with zinc and antioxidants

AIM

To assess the cost effectiveness of high dose zinc and antioxidants for delaying and reducing the progression of early age related macular degeneration (AMD).

BACKGROUND

AMD is the leading cause of severe vision impairment and blindness in older people throughout the developed world. It currently affects around 420 000 people in the United Kingdom.

METHODS

A cost utility analysis (CUA) was conducted to estimate the cost per quality adjusted life year (QALY) for screening a cohort of men and women, aged 55 years and over, for early AMD and then treating them with zinc and antioxidants. The incremental CUA was based on a decision analytic model, comparing screening with a no screening comparator (current practice). Extensive one way sensitivity analysis of parameters was conducted to determine the robustness of the model.

RESULTS

In this model the cost effectiveness of screening for early AMD was pound 22 722 per quality adjusted life year (QALY) saved. The cost per QALY decreased to pound 18 948 if photodynamic therapy with verteporfin savings were included.

CONCLUSIONS

Screening for, and prophylactic treatment of, early AMD is estimated to cost around pound 22 700 per QALY saved. This cost falls within accepted levels to warrant further investigation. These findings have implications for ophthalmic practice and healthcare planning.

[Münster age- and retina study (MARS). Association between risk factors for arteriosclerosis and age-related macular degeneration]

BACKGROUND

The association between arteriosclerosis and age-related macular degeneration (AMD) has only been examined in a few studies and the data is still very inconsistent.

METHODS

A cross sectional study was initiated with 730 patients from the Münster age and retina study (MARS) which examines patients in the age range 60 to 80 years old who were referred by ophthalmologists from the Muenster area. Patients with narrow angle glaucoma were excluded. All patients underwent a standardized ophthalmoscopic examination und were classified into four groups: group 1 without AMD ( n=190), group 2 with unilateral or bilateral early forms of AMD ( n=340), group 3 with unilateral late forms of AMD ( n=139) and group 4 with bilateral late forms of AMD ( n=50). By means of these groups it was tested if there was a significant difference between the different risk factors for arteriosclerosis.

RESULTS

The mean age was 72 years and 58% were women and the sex distribution within the different groups did not differ significantly (all trend tests with p>0.1). General risk factors for arteriosclerosis such as diabetes, body-mass-index and hypertension did not differ significantly (all trend tests with p>0.1). The number of smokers increased significantly with the severity of AMD ( p=0.02). Furthermore, various lipids were examined, adjusted for age and sex and showed significant decrease of HDL ( p=0.087) and significant increases of the HDL/LDL quotient ( p=0.0007) and the non-sober triglyceride values ( p=0.0058) correlated with the severity of AMD.

CONCLUSIONS

There was a highly significant, direct association of indicators of dyslipidemia such as increasing HDL/LDL quotient and decreasing HDL with the severity of AMD. These results were underlined by increased triglyceride levels even if they were taken non-sober. The results must be interpreted with caution due to the explorative character of the evaluation.

Statin and aspirin therapy are associated with decreased rates of choroidal neovascularization among patients with age-related macular degeneration

PURPOSE

To investigate the relationship between statin and aspirin use and the risk of choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD).

DESIGN

Retrospective consecutive case series.

METHODS

All patients 60 years and older with AMD who were seen between January 1, 1990, and March 1, 2003, at the San Francisco Veterans Affairs Hospital Eye Clinic with fundus photographs were included. Patients with other diagnoses predisposing to CNV or incomplete medical records were excluded. The main outcome measure was angiographically evident CNV. Diagnosis was based on review of fundus photographs and fluorescein angiograms in masked fashion; medical records were reviewed for variables possibly predisposing to CNV or statin use. For patients with CNV, age of onset was recorded; those without CNV were treated as censored. Age-related macular degeneration disease status and time of onset of CNV was compared between patients treated or not treated with statins for at least 6 months.

RESULTS

Of 326 patients with AMD, 104 had CNV, 204 had dry AMD, and 18 had geographic atrophy (GA). Of CNV subjects, 21 (20%) used statins, compared with 77 (38%) of dry AMD subjects without GA and 6 (33%) of controls with GA (hazard ratio = 0.51, 95% confidence interval (CI) = 0.31-0.86, P =.01). Aspirin use was also significantly associated with decreased rates of CNV; 62 CNV subjects (60%) used aspirin, compared with 154 (75%) dry AMD subjects without GA or 12 (67%) with GA (hazard ratio = 0.63, 95% CI = 0.40-0.98, P =.04).

CONCLUSIONS

Therapy with statins or aspirin is associated with decreased rates of CNV among AMD patients. Additional study with a prospective and/or randomized trial of statin and aspirin use in AMD patients is warranted.

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.

Measurement of the economic impact of visual impairment from age-related macular degeneration in Australia

The purpose of this report was to: (i) outline the potential value of health economic studies into age-related macular degeneration (AMD); (ii) provide an overview of health economic studies pertinent to AMD; and (iii) outline the basic frame work of cost-of-illness studies (a useful first step in applying economic methods). The detection and management of sensory loss in the elderly plays a key role in the Australian Government's Healthy Ageing Strategy. Age-related macular degeneration is currently the leading cause of blindness in elderly Australians. Although a large proportion of AMD cases remain untreatable, the introduction of photo-dynamic therapy provides a relatively expensive and possibly cost-effective innovation for others. Antioxidant therapy has also been proven effective in reducing progression of early to late disease. The discipline of economics can contribute to an understanding of AMD prevention and treatment through: (i) describing the current burden of disease; (ii) predicting the changes in the burden of disease over time, and (iii) evaluating the efficiency of different interventions. Cost-of-illness studies have been performed in many fields of medicine. Little work, however, has been done on describing the economic impact from AMD. A number of different economic evaluation methods can be used in judging the efficiency of possible interventions to reduce the disease burden of AMD. Although complementary in nature, each has specific uses and limitations. Studies of the economic impact of eye diseases are both feasible and necessary for informed health care decision-making.

Retinal vessel wall signs and the 5 year incidence of age related maculopathy: the Blue Mountains Eye Study

AIMS

To assess whether retinal arteriolar wall changes (focal narrowing and arteriovenous nicking) are associated with an increased 5 year risk of age related maculopathy (ARM).

METHODS

The Blue Mountains Eye Study examined 3654 residents aged 49+ years living in a defined area, during 1992-4 (82.4% participation). After 5 years, 2335 surviving participants (75.1%) were re-examined during 1997-9. Retinal photographs were graded using the Wisconsin ARM grading system. Incident late (neovascular or atrophic) or early stage ARM was defined using a side by side grading method. Focal arteriolar narrowing (localised constricted arteriolar segments causing a sausage-like appearance), and arteriovenous (AV) nicking (constriction on both sides of the venule where crossed by an arteriole), were graded by comparison with standard photographs. All retinal vessels passing through a circumferential zone 0.5-1.0 disc diameters from the optic disc margin were measured from digitised images. Summarised estimates for central retinal arteriolar equivalent (CRAE) represent an average diameter of arterioles for that eye. Associations were assessed after adjusting for age, sex, smoking, mean arterial blood pressure, and other vascular risk factors.

RESULTS

Of 2314 baseline participants at risk of late stage ARM, either late stage lesion developed in 34 participants (1.5%). Of 2203 at risk of early stage ARM, this sign developed in 197 participants (8.9%). Focal arteriolar narrowing was present at baseline in at least one eye of 162 survivors (6.9%) and severe AV nicking was present in 187 people (8.1%). Over 5 years, 4.9% of subjects with and 1.2% of those without focal narrowing developed either late stage ARM lesion, age adjusted relative risk (RR) 2.3, 95% confidence interval (CI) 1.0 to 5.1, multivariate adjusted odds ratios (OR) 2.1 (95% CI 0.9 to 4.9). Similarly, 3.7% of subjects with and 1.3% of those without severe AV nicking developed late ARM lesions, age adjusted RR 2.1 (95% CI 0.9 to 5.1), multivariate adjusted OR 2.2 (95% CI 0.9 to 5.6). Corresponding age adjusted RR and multivariate adjusted OR for development of early stage ARM were 1.4 (95% CI 0.9 to 2.0) and 1.3 (95% CI 0.8 to 2.1) for focal arteriolar narrowing, and 1.6 (95% CI 1.0 to 2.3) and 1.8 (95% CI 1.1 to 2.9) for severe AV nicking, respectively. No associations between baseline CRAE and 5 year incident late or early stage ARM were found.

CONCLUSIONS

Although of borderline statistical significance, the consistent associations found in this study suggest that structural retinal arteriolar changes may either contribute to ARM progression or may share common pathological pathways with ARM.

Progression of age-related macular degeneration: association with dietary fat, transunsaturated fat, nuts, and fish intake

BACKGROUND

Individuals with early or intermediate stages of age-related macular degeneration (AMD) make up a large, growing segment of the elderly population. Evidence is sparse regarding modifiable factors that may decrease the risk of progression to the advanced forms of AMD.

OBJECTIVE

To advise patients with a high risk for advanced forms of AMD about preventive measures through our evaluation of the relationship between dietary fat intake and the progression of early or intermediate AMD to the advanced stages of the disease associated with visual loss.

DESIGN

A prospective cohort study with an average follow-up time of 4.6 years.

SETTING

A hospital-based clinical retinal practice specializing in macular degeneration. Patients The 261 participants were aged 60 years and older and had some sign of nonexudative AMD and visual acuity of 20/200 or better in at least 1 eye. Main Outcome Measure Progression to advanced AMD, which was defined as having geographic atrophy or neovascular disease.

RESULTS

Higher total fat intake increased the risk of progression to the advanced forms of AMD, with a relative risk (RR) of 2.90 (95% confidence interval, 1.15-7.32) for the highest fat-intake quartile relative to the lowest fat-intake quartile, after controlling for other factors (P trend =.01). Animal fat intake was associated with a 2-fold increased risk of progression (RR, 2.29 for the highest quartile compared with the lowest quartile; 95% confidence interval, 0.91-5.72), although the trend for increasing risk with higher animal fat intake was not significant (P=.09). Higher vegetable fat intake had a stronger relationship with increased risk of AMD progression with an RR of 3.82 (95% confidence interval, 1.58-9.28) for the highest quartile compared with the lowest quartile (P trend =.003). Saturated, monounsaturated, polyunsaturated, and transunsaturated fats increased the likelihood of progression (RR, 2.09 and P trend =.08; RR, 2.21 and P trend =.04; RR, 2.28 and P trend =.04; RR, 2.39 and P trend =.008, respectively). Higher fish intake was associated with a lower risk of AMD progression among subjects with lower linoleic acid intake. Processed baked goods, which are higher in some of these fats, increased the rate of AMD progression approximately 2-fold, and nuts were protective.

CONCLUSIONS

Among individuals with the early or intermediate stages of AMD, total and specific types of fat intake, as well as some fat-containing food groups, modified the risk of progression to advanced AMD. Fish intake and nuts reduced risk. Since advanced AMD is associated with visual loss and reduced quality of life, these preventive measures deserve additional research and greater emphasis.

Assessment of multifocal electroretinogram abnormalities and their relation to morphologic characteristics in patients with large drusen

OBJECTIVES

To determine the extent of functional changes in the first-order kernel multifocal electroretinogram (mfERG) responses in patients with large drusen by means of a localized analysis and to determine correlations between mfERG responses and morphologic changes.

METHODS

Thirty-one eyes from 20 patients ages 58 to 84 years with large drusen (> or =5 drusen > or =63 microm diameter) were studied. The mfERGs were recorded with a stimulus of 103 hexagons and a flash intensity of 2.67 candela (cd).s-1.m-2. Each of the 103 single first-order kernel mfERG responses was analyzed and compared with those of age-matched healthy control subjects. Imaging studies, including color stereo fundus photography, red-free fundus photography, and fluorescein angiography, were performed in all patients, and morphologic changes (drusen in red-free fundus photography, staining or window defect in fluorescein angiography) were determined with a digital measurement tool. The mfERG responses were correlated to areas with and without morphologic changes.

RESULTS

Reduced responses were found in 10.0% (scalar products) and 4.0% (response densities) and delayed implicit times in 13.8% (N1), 18.9% (P1), and 23.8% (N2) of all mfERGs. Abnormal mfERG responses extended up to 25 degrees in radius. Significant morphologic-functional relations were detected in only a few patients. Abnormal mfERG variables were present in areas without morphologic changes.

CONCLUSIONS

Patients with large drusen exhibit functional changes in the cone-driven pathways evaluated by the mfERG, indexed particularly by implicit times. Morphologically visible changes do not predict retinal function. Large drusen are associated with a more general retinal dysfunction.

Age-related macular degeneration: etiology, pathogenesis, and therapeutic strategies

Age-related macular degeneration is the principal cause of registered legal blindness among those aged over 65 in the United States, western Europe, Australia, and Japan. Despite intensive research, the precise etiology of molecular events that underlie age-related macular degeneration is poorly understood. However, investigations on parallel fronts are addressing this prevalent public health problem. Sophisticated biochemical and biophysical techniques have refined our understanding of the pathobiology of drusen, geographic atrophy, and retinal pigment epithelial detachments. Epidemiological identification of risk factors has facilitated an intelligent search for underlying mechanisms and fueled clinical investigation of behavior modification. Gene searches have not only brought us to the cusp of identifying the culpable gene loci in age-related macular degeneration, but also localized genes responsible for other macular dystrophies. Recent and ongoing investigations, often cued by tumor biology, have revealed an important role for various growth factors, particularly in the neovascular form of the condition. Transgenic and knockout studies have provided important mechanistic insights into the development of choroidal neovascularization, the principal cause of vision loss in age-related macular degeneration. This in turn has culminated in preclinical and clinical trials of directed molecular interventions.

Sunglasses and sunglass standards

Sunglasses and sunglass standards are reviewed from the point of view of the history of sunglasses and the development of sunglass standards. The need for eye protection from solar radiation is discussed and the provisions of the various national sunglass standards are discussed in relation to that need.