Variation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (AMD) in populations of European ancestry (study dates ranged from 1990 to 2009). The authors included only the 10,623 control subjects from these studies who were classified as having no evidence of AMD, since variation within the APOE gene has previously been associated with AMD. In an analysis stratified by study center, gender, and smoking status, there was a decreasing frequency of the APOE ε4 isoform with increasing age (χ2 for trend = 14.9 (1 df); P = 0.0001), with a concomitant increase in the ε3 isoform (χ2 for trend = 11.3 (1 df); P = 0.001). The association with age was strongest in ε4 homozygotes; the frequency of ε4 homozygosity decreased from 2.7% for participants aged 60 years or less to 0.8% for those over age 85 years, while the proportion of participants with the ε3/ε4 genotype decreased from 26.8% to 17.5% across the same age range. Gender had no significant effect on the isoform frequencies. This study provides strong support for an association of the APOE gene with human longevity.

Copy Number Variants (CNVs) are now recognized as playing a significant role in complex disease etiology. Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss in the western world. While a number of genes and environmental factors have been associated with both risk and protection in AMD, the role of CNVs has remained largely unexplored. We analyzed the two major AMD risk-associated regions on chromosome 1q32 and 10q26 for CNVs using Multiplex Ligation-dependant Probe Amplification. The analysis targeted nine genes in these two key regions, including the Complement Factor H (CFH) gene, the 5 CFH-related (CFHR) genes representing a known copy number “hotspot”, the F13B gene as well as the ARMS2 and HTRA1 genes in 387 cases of late AMD and 327 controls. No copy number variation was detected at the ARMS2 and HTRA1 genes in the chromosome 10 region, nor for the CFH and F13B genes at the chromosome 1 region. However, significant association was identified for the CFHR3-1 deletion in AMD cases (p = 2.38×10−12) OR = 0.31, CI-0.95 (0.23–0.44), for both neovascular disease (nAMD) (p = 8.3×10−9) OR = 0.36 CI-0.95 (0.25–0.52) and geographic atrophy (GA) (p = 1.5×10−6) OR = 0.36 CI-0.95 (0.25–0.52) compared to controls. In addition, a significant association with deletion of CFHR1-4 was identified only in patients who presented with bilateral GA (p = 0.02) (OR = 7.6 CI-0.95 1.38–41.8). This is the first report of a phenotype specific association of a CNV for a major subtype of AMD and potentially allows for pre-diagnostic identification of individuals most likely to proceed to this end stage of disease.

PURPOSE

To assess the histopathological changes in a postmortem sample derived from an eye donor with Macular Telangiectasia Type 2 (MacTel type 2) to gain further insight into the cause of the disease.

DESIGN

Clinicopathological case report

PARTICIPANTS

Postmortem tissue was collected from 5 different donors: one MacTel type 2 patient, one healthy control, two type 2 diabetic patients; one with retinopathy and one without retinopathy, and one patient with unilateral Coat’s disease.

METHODS

Macular pigment distribution in the posterior part of freshly dissected eyes was documented by macro photography. Paraffin sections from both the macular and peripheral regions were assessed using antigen retrieval and immunohistochemistry to study the distribution of cell-specific markers. Blood vessels were visualized with antibodies directed against collagen IV and claudin5, glial cells with antibodies against glial fibrillary acidic protein (GFAP), vimentin, glutamine synthetase (GS) and retinaldehyde binding protein (RLBP1, also known as CRALBP), microglia with an antibody against allograft inflammatory factor 1 (AIF1, also known as Iba1) and photoreceptors with antibodies against rhodopsin and opsin. Using anatomical landmarks the sections were then matched with the macular pigment distribution and a fluorescein angiogram of the patient that was taken before the patient’s death.

MAIN OUTCOME MEASURES

Presence and distribution of macular pigment and cell-specific markers.

RESULTS

Macular pigment was absent in the macula. Furthermore, abnormally dilated capillaries were identified in a macular region that correlated spatially with regions of fluorescein leakage in an angiogram that was taken 12 years prior to death. These telangiectatic vessels displayed a marked reduction of the basement membrane component collagen IV, indicating vascular pathology. GFAP was limited to retinal astrocytes and no reactive Müller cells were identified. Importantly, reduced immunoreactivity with Müller cell markers (vimentin, GS and RLBP1) in the macula was observed. The area that lacked Müller cells corresponded with the region of depleted macular pigment.

CONCLUSIONS

These findings suggest that macular Müller cell loss or dysfunction is a critical component of MacTel type 2, which may have implications for future treatment strategies.

Background

Tobacco smoking is a risk factor for age-related macular degeneration, but studies of ex-smokers suggest quitting can reduce the risk.

Methods

We fitted a function predicting the decline in risk of macular degeneration after quitting to data from 7 studies involving 1,488 patients. We assessed the cost-effectiveness of smoking cessation in terms of its impact on macular degeneration-related outcomes for 1,000 randomly selected U.S. smokers. We used a computer simulation model to predict the incidence of macular degeneration and blindness, the number of quality-adjusted life-years (QALYs), and direct costs (in 2004 U.S. dollars) until age 85 years. Cost-effectiveness ratios were based on the cost of the Massachusetts Tobacco Control Program. Costs and QALYs were discounted at 3% per year.

Results

If 1,000 smokers quit, our model predicted 48 fewer cases of macular degeneration, 12 fewer cases of blindness, and a gain of 1,600 QALYs. Macular degeneration-related costs would decrease by $2.5 million if the costs of caregivers for people with vision loss were included, or by $1.1 million if caregiver costs were excluded. At a cost of $1,400 per quitter, smoking cessation was cost-saving when caregiver costs were included, and cost about $200 per QALY gained when caregiver costs were excluded. Sensitivity analyses had a negligible impact. The cost per quitter would have to exceed $77,000 for the cost per QALY for smoking cessation to reach $50,000, a threshold above which interventions are sometimes viewed as not cost-effective.

Conclusion

Smoking cessation is unequivocally cost-effective in terms of its impact on age-related macular degeneration outcomes alone.

Age-related macular degeneration (AMD) is responsible for the majority of visual impairment in the Western world. The role of cholesterol-lowering medications, HMG Co-A reductase inhibitors or statins, in reducing the risk of AMD or of delaying its progression has not been fully investigated. A 3-year prospective randomized controlled trial of 40 mg simvastatin per day compared to placebo in subjects at high risk of AMD progression is described. This paper outlines the primary aims of the Age-Related Maculopathy Statin Study (ARMSS), and the methodology involved. Standardized clinical grading of macular photographs and comparison of serial macular digital photographs, using the International grading scheme, form the basis for assessment of primary study outcomes. In addition, macular function is assessed at each visit with detailed psychophysical measurements of rod and cone function. Information collected in this study will assist in the assessment of the potential value of HMG Co-A reductase inhibitors (statins) in reducing the risk of AMD progression.

Background

Intravitreal ranibizumab prevents vision loss and improves visual acuity in patients with neovascular age-related macular degeneration, but it is expensive, and efficacy beyond 2 years is uncertain.

Methods

We assessed the cost-effectiveness of ranibizumab compared with no ranibizumab over 10 years, using randomized trial efficacy data for the first 2 years, post-trial efficacy assumptions, and ranibizumab acquisition costs ranging from the wholesale price ($1,950 per dose) to the price of bevazicumab ($50), a similar molecule which may be equally efficacious. We used a computer simulation model to estimate the probability of blindness, the number of quality-adjusted life-years (QALYs), direct costs (in 2004 U.S. dollars), and cost-effectiveness ratios for a 67-year old woman. Costs and QALYs were discounted at 3% per year.

Results

The probability of blindness over 10 years was reduced from 56% to 34% if ranibizumab was efficacious for only 2 years, 27% if efficacy was maintained for a further 2 years only (base-case scenario), and 17% if visual acuity at 4 years was then sustained. It was cost-saving under all price assumptions, when caregiver costs were included. When caregiver costs were excluded, the cost per QALY for the base-case ranged from $5,600, assuming the bevazicumab price, to $91,900 assuming the wholesale ranibizumab price. The cost per QALY was < $50,000 when the cost of ranibizumab was less than $1000.

Conclusion

From a societal perspective, ranibizumab was cost-saving. From a health care funder's perspective, ranibizumab was an efficient treatment when it cost less than $1000 per dose.

Objective To evaluate the effectiveness of dietary antioxidants in the primary prevention of age related macular degeneration (AMD).

Design Systematic review and meta-analysis.

Data sources Search of seven databases without limits on year or language of publication, and retrieval of references in pertinent reviews and articles.

Methods Two reviewers independently searched the databases and selected the studies, using standardised criteria. Randomised clinical trials and prospective cohort studies were included. Of the 4192 abstracts initially identified, 12 studies (nine prospective cohort studies and three randomised clinical trials) met the selection criteria and were included. Data extraction and study quality evaluation were independently reviewed, using standardised criteria. Results were pooled quantitatively using meta-analytic methods.

Results The nine prospective cohort studies included 149 203 people, with 1878 incident cases of early AMD. The antioxidants investigated differed across studies, and not all studies contributed to the meta-analysis of each antioxidant. Pooled results from prospective cohort studies indicated that vitamin A, vitamin C, vitamin E, zinc, lutein, zeaxanthin, α carotene, β carotene, β cryptoxanthin, and lycopene have little or no effect in the primary prevention of early AMD. The three randomised clinical trials did not show that antioxidant supplements prevented early AMD.

Conclusions There is insufficient evidence to support the role of dietary antioxidants, including the use of dietary antioxidant supplements, for the primary prevention of early AMD.

SUMMARY

Age related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly population worldwide. While recent studies have demonstrated strong genetic associations of single nucleotide polymorphisms within a number of genes and AMD, other modes of regulation are also likely to play a role in its etiology. We identified a significantly decreased level of methylation on the IL17RC promoter in AMD patients. Further, we showed that hypomethylation of the IL17RC promoter in AMD patients led to an elevated expression of its protein and mRNA in peripheral blood as well as in the affected retina and choroid, suggesting that the DNA methylation pattern and expression of IL17RC may potentially serve as a biomarker for the diagnosis of AMD and likely plays a role in disease pathogenesis.

Despite significant progress in the identification of genetic loci for age-related macular degeneration (AMD), not all of the heritability has been explained. To identify variants which contribute to the remaining genetic susceptibility, we performed the largest meta-analysis of genome-wide association studies to date for advanced AMD. We imputed 6 036 699 single-nucleotide polymorphisms with the 1000 Genomes Project reference genotypes on 2594 cases and 4134 controls with follow-up replication of top signals in 5640 cases and 52 174 controls. We identified two new common susceptibility alleles, rs1999930 on 6q21-q22.3 near FRK/COL10A1 [odds ratio (OR) 0.87; P = 1.1 × 10−8] and rs4711751 on 6p12 near VEGFA (OR 1.15; P = 8.7 × 10−9). In addition to the two novel loci, 10 previously reported loci in ARMS2/HTRA1 (rs10490924), CFH (rs1061170, and rs1410996), CFB (rs641153), C3 (rs2230199), C2 (rs9332739), CFI (rs10033900), LIPC (rs10468017), TIMP3 (rs9621532) and CETP (rs3764261) were confirmed with genome-wide significant signals in this large study. Loci in the recently reported genes ABCA1 and COL8A1 were also detected with suggestive evidence of association with advanced AMD. The novel variants identified in this study suggest that angiogenesis (VEGFA) and extracellular collagen matrix (FRK/COL10A1) pathways contribute to the development of advanced AMD.