Risk factors for Age-related Macular Degeneration (AMD) involves genetic variations in the alternative pathway of complement inhibitor factor H. The complement system is part of the innate and adaptive immune system. Smoking is the only environmental factor known to increase the risk of Age-related Macular Degeneration (AMD). Using serum samples of Age-related Macular Degeneration (AMD) patients and controls the investigators will test the hypothesis that smoking increases Age-related Macular Degeneration (AMD) by increasing complement activation; and that this is positively correlated with known disease variations in the complement factor H (CFH) gene.
Description: Assessment of Age based on clinical records.Measure: Age in Study Participants Time: baseline visit
Description: Patients were asked during patient interview as to their history of smoking (current, never or ever was assessed).Measure: Number of Participants That Are Smokers Time: Day 1 of study
Description: To assess for risk of AMD. Cells remaining from the serum separation were used for genetic analysis. Genomic DNA was extracted using a commercially available DNA extraction kit according to the manufacturer's instructions (QIAmp® DNA Mini; Qiagen). The AMD-associated SNP was genotyped at CFH (rs3766404), locus using PCR-based assays (TaqMan assays, Applied Biosystems), according to the manufacturer's instructions. Only white Caucasians in the population were included.Measure: Number of Participants With Signal Nucleotide Polymorphisms for CFH Locus Time: Blood sample collection at contact
Description: To assess systemic complement activation, venus blood is collected. Complement component analysis was performed as a fee for service at the National Jewish Health Advanced Diagnostic Laboratories, using commercially available kits. Samples were analyzed in two batches in which the ELISA displayed difference sensitivities. Therefore data was normalized within each batch to values obtained from control subjects. Data reported represents the average of the two batches.Measure: Percentage of Complement Pathway Proteins in the Serum Time: within a month of obtaining blood sample
There is one SNP
The AMD-associated SNP was genotyped at CFH (rs3766404), locus using PCR-based assays (TaqMan assays, Applied Biosystems), according to the manufacturer's instructions.