Age related macular degeneration

Age-related macular degeneration (AMD) is a degenerative disease of the human retina affecting individuals over the age of 55 years. This heterogeneous condition arises from a complex interplay between age, genetics, and environmental factors including smoking and diet. It is the leading cause of blindness in industrialized countries. Worldwide, the number of people with AMD is predicted to increase from 196 million in 2020 to 288 million by 2040. By this time, Asia is predicted to have the largest number of people with the disease. Distinct patterns of AMD prevalence and phenotype are seen between geographical areas that are not explained fully by disparities in population structures. AMD is classified into early, intermediate, and late stages. The early and intermediate stages, when visual symptoms are typically absent or mild, are characterized by macular deposits (drusen) and pigmentary abnormalities. Through risk prediction calculators, grading these features helps predict the ...

We examined familial aggregation and risk of age-related macular degeneration in the Utah population using a population-based case-control study. Over one million unique patient records were searched within the University of Utah Health Sciences Center and the Utah Population Database (UPDB), identifying 4764 patients with AMD. Specialized kinship analysis software was used to test for familial aggregation of disease, estimate the magnitude of familial risks, and identify families at high risk for disease. The population-attributable risk (PAR) for AMD was calculated to be 0.34. Recurrence risks in relatives indicate increased relative risks in siblings (2.95), first cousins (1.29), second cousins (1.13), and parents (5.66) of affected cases. There were 16 extended large families with AMD identified for potential use in genetic studies. Each family had five or more living affected members. The familial aggregation of AMD shown in this study exemplifies the merit of the UPDB and supports recent research demonstrating significant genetic contribution to disease development and progression.

Address: Department of Psychology, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK Email: Jan Mitchell* - j.mitchell@rhul.ac.uk; Clare Bradley - c.bradley@rhul.ac.uk * Corresponding author ... Abstract Background: The Age-related Macular Degeneration Alliance ...

Xanthophylls are oxygenated carotenoids abun-dant in the human food supply. Lutein, zeaxanthin, and cryptoxanthin are major xanthophyll carotenoids in human plasma. The consumption of these xanthophylls is directly associated with reduction in the risk of ...

Age-related macular degeneration (AMD) is the most frequent cause of irreversible blindness in the elderly in developed countries. Our previous studies implicated activation of complement in the formation of drusen, the hallmark lesion of AMD. Here, we show that factor H (HF1), the major inhibitor of the alternative complement pathway, accumulates within drusen and is synthesized by the retinal pigmented epithelium. Because previous linkage analyses identified chromosome 1q25-32, which harbors the factor H gene (HF1/CFH), as an AMD susceptibility locus, we analyzed HF1 for genetic variation in two independent cohorts comprised of ≈900 AMD cases and 400 matched controls. We found association of eight common HF1 SNPs with AMD; two common missense variants exhibit highly significant associations (I62V, χ2 = 26.1 and P = 3.2 × 10-7 and Y402H, χ2 = 54.4 and P = 1.6 × 10-13). Haplotype analysis reveals that multiple HF1 variants confer elevated or reduced risk of AMD. One common at-risk haplotype is present at a frequency of 50% in AMD cases and 29% in controls [odds ratio (OR) = 2.46, 95% confidence interval (1.95-3.11)]. Homozygotes for this haplotype account for 24% of cases and 8% of controls [OR = 3.51, 95% confidence interval (2.13-5.78)]. Several protective haplotypes are also identified (OR = 0.44-0.55), further implicating HF1 function in the pathogenetic mechanisms underlying AMD. We propose that genetic variation in a regulator of the alternative complement pathway, when combined with a triggering event, such as infection, underlie a major proportion of AMD in the human population.

To assess the effects of a single 100-mg dose of sildenafil citrate on visual function in men with early-stage age-related macular degeneration. Randomized double-blind placebo-controlled clinical trial. Nine men (mean age 71 years, range 59-85 years) with early-stage (minimal visual impairment and large drusen in the macula) age-related macular degeneration and 20/40 or better-corrected visual acuity in at least one eye were prospectively randomized to receive either placebo or sildenafil citrate (Viagra; Pfizer Inc, New York, New York) 100 mg as a single oral dose. After 7-14 days, they received the alternate treatment. Subjects underwent visual acuity, Amsler grid, color discrimination (D15), traffic light, Humphrey perimetry, and photo-stress testing in each eye before and at specific intervals within 8 hours after dosing. Compared with placebo, no pattern of errors were evident in any visual function test following sildenafil administration. No statistically or clinically relevant changes from baseline were observed in visual acuity, Humphrey perimetry (corrected pattern standard deviation), D15 color discrimination, or photo-stress tests. No clinically relevant changes were observed in the Amsler grid or traffic light tests. Sildenafil treatment was associated with transient mild or moderate headache, flushing, and rhinitis. There were no visual adverse events spontaneously reported to the investigator. A single 100-mg dose of sildenafil was well tolerated and produced no acute visual effects or exacerbation of preexisting visual impairment in nine men with early-stage age-related macular degeneration.

Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness among older adults in the USA and throughout the developed world. Etiological research suggests that AMD is a complex disease, caused by the actions and interactions of multiple genes and environmental factors. Familial aggregation studies, twin studies, and segregation analyses have provided strong evidence for the heritability

To systematically review the evidence on dietary omega-3 fatty acid and fish intake in the primary prevention of age-related macular degeneration (AMD). Seven databases were systematically searched with no limits on publication year or language using standardized criteria. Randomized controlled trials and prospective cohort, case-control, and cross-sectional studies were included. Of 2754 abstracts identified, 3 prospective cohort, 3 case-control, and 3 cross-sectional studies met the criteria. Measures of associations were pooled quantitatively using meta-analytic methods. Nine studies provided data on a total sample of 88 974 people, including 3203 AMD cases. A high dietary intake of omega-3 fatty acids was associated with a 38% reduction in the risk of late AMD (pooled odds ratio [OR], 0.62; 95% confidence interval [CI], 0.48-0.82). Fish intake at least twice a week was associated with a reduced risk of both early AMD (pooled OR, 0.76; 95% CI, 0.64-0.90) and late AMD (pooled OR, ...

To investigate the association between cataract surgery and the rate of photodynamic therapy (PDT) for age-related macular degeneration (AMD). Observational population-based retrospective case-control study. All members in a district of the largest health maintenance organization (HMO) in Israel > 50 years old on January 1, 2001, who did not terminate their membership through May 31, 2005 (139 894 members). All PDT procedures for AMD performed in the study population between January 1, 2001 and May 31, 2005 (283 patients) and all cataract surgeries performed between January 1, 2001 and December 31, 2003 (5913 patients) were documented. We extracted clinical information from the chronic disease registry of the HMO as well as demographic and socioeconomic information. For each patient that underwent cataract surgery, 5 HMO members matched in age, gender, chronic diseases (systemic hypertension, diabetes, hyperlipemia, and ischemic heart disease), place of residence, country of birth and socioeconomic status, who did not undergo cataract surgery, were randomly chosen as controls (n = 29 565). The rate for undergoing PDT at different time periods after cataract surgery. Fifty (0.85%) cataract patients and 94 control cases (0.32%) underwent PDT after cataract surgery (P<0.0001, chi-square test). A significant rise in PDT rate was noticed in cataract patients compared to controls during the first 6 months after surgery (P = 0.004, chi-square test). Between 6 and 12 months postoperatively, the PDT rates were similar in both groups. However, a more significant rise in PDT rates occurred between 1 and 1.5 years after surgery (P<0.0001, chi-square test). The Kaplan-Meier PDT-free survival curve of cataract patients was significantly worse than that of the controls (P<0.0001, chi-square test; P = 33.7, log-rank test). The hazard ratio for cataract patients compared to controls to undergo PDT after surgery was 2.7 (confidence interval = 2.4-5.7). The most significant factors to reduce the time to PDT were advanced age followed by having had cataract surgery, place of birth, socioeconomic status, and hyperlipidemia (Cox proportional hazards survival regression). We identified an increased rate of PDT, presumably for subfoveal AMD, 1 to 1.5 years after cataract surgery.

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.

Age-related macular degeneration (AMD) is a leading cause of blindness in people aged ≥50 years. Wet AMD in particular has a major impact on patient quality of life and imposes substantial burdens on healthcare systems. This systematic review examined the cost-effectiveness data for current therapeutic options for wet AMD. PubMed and EMBASE databases were searched for all articles reporting original cost-effectiveness analyses of wet AMD treatments. The Centre for Reviews and Dissemination and Cochrane Library databases were searched for all wet AMD health technology assessments (HTAs). Overall, 44 publications were evaluated in full and included in this review. A broad range of cost-effectiveness analyses were identified for the most commonly used therapies for wet AMD (pegaptanib, ranibizumab and photodynamic therapy [PDT] with verteporfin). Three studies evaluated the cost effectiveness of bevacizumab in wet AMD. A small number of analyses of other treatments, such as laser photo...

Most of current concepts for a visual prosthesis are based on neuronal electrical stimulation at different locations along the visual pathways within the central nervous system. The different designs of visual prostheses are named according to their locations (i.e., cortical, optic nerve, subretinal, and epiretinal). Visual loss caused by outer retinal degeneration in diseases such as retinitis pigmentosa or age-related macular degeneration can be reversed by electrical stimulation of the retina or the optic nerve (retinal or optic nerve prostheses, respectively). On the other hand, visual loss caused by inner or whole thickness retinal diseases, eye loss, optic nerve diseases (tumors, ischemia, inflammatory processes etc.), or diseases of the central nervous system (not including diseases of the primary and secondary visual cortices) can be reversed by a cortical visual prosthesis. The intent of this article is to provide an overview of current and future concepts of retinal and optic nerve prostheses. This article will begin with general considerations that are related to all or most of visual prostheses and then concentrate on the retinal and optic nerve designs. The authors believe that the field has grown beyond the scope of a single article so cortical prostheses will be described only because of their direct effect on the concept and technical development of the other prostheses, and this will be done in a more general and historic perspective..