ABSTRACT
PURPOSE: To explore the association of two single nucleotide polymorphisms (SNPs) in the CX3CR1 gene with grades of age-related macular degeneration (AMD) in a population-based setting. METHODS: The Thessaloniki Eye study is a cross-sectional population-based epidemiologic study of chronic eye diseases in Thessaloniki, Greece. A total of 371 subjects were included and classified according to their AMD status. Subjects with AMD Grades 0-1 (n = 188) were compared to those with AMD Grades 2-3 (n = 138), to those with AMD Grade 4 (geographic atrophy) (n = 20) and to those with AMD Grade 5 (neovascular AMD) (n = 25) with regard to the presence of CX3CR1 polymorphisms (V249I and T280M). Polychotomous logistic regression analysis adjusted for age, gender, and smoking was conducted and the log-additive allelic model was preferred. RESULTS: Participants with AMD Grade 4 were approximately three times more likely to carry the VI249 and nine times more likely to carry the II249 alleles, compared to those with AMD Grades 0-1, whereas those with AMD Grades 2-3 or Grade 5 did not differ. The T280M polymorphism was not associated with either AMD Grades 2-3 or AMD Grades 4 or 5. CONCLUSION: In this Greek population, after adjusting for known risk factors, increased risk of geographic atrophy (GA) AMD among the carriers of the V249I polymorphism in the CX3CR1 gene was found. Our study failed to reveal any association with the T280M polymorphism reported in previous studies. Additional studies in different ethnic populations using standardized methodology are needed in order to confirm this association.
Subject(s)
Genetic Variation/genetics , Geographic Atrophy/genetics , Polymorphism, Single Nucleotide , Receptors, Chemokine/genetics , White People/genetics , Aged , Alleles , CX3C Chemokine Receptor 1 , Cross-Sectional Studies , DNA Mutational Analysis , Female , Genotyping Techniques , Geographic Atrophy/ethnology , Greece/epidemiology , Humans , Male , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Risk FactorsABSTRACT
PURPOSE: To explore new features of the optic nerve head morphology using the Heidelberg retina tomograph (HRT) and to assess their discriminating power between glaucomatous patients and normal subjects. METHODS: HRT reports, exported as TIFF images, from 97 normal subjects and 97 primary open-angle glaucoma (POAG) patients were used. For each image the contour of the dominant region of the optic disc cupping surface (dROCS) was transformed into a data series by calculating the distance of each contour pixel from the centroid. The length of contour (LC) and SD of contour (SDC) along with the dROCS area divided by the disc area (DA) HRT parameter were examined as novel parameters. RESULTS: The means of LC and SDC, after adjustment for cup area (CA) and DA HRT parameters, and dROCS/DA, after adjustment for CA, presented statistically significant differences (ANCOVA, P < 0.001) between the two groups. Using LC and SDC together in discriminant analysis with leave-one-out cross-validation, 75.3% of cases were correctly classified. Using dROCS/DA together with SDC, the correct classification percentage was 80.6%. The area under the ROC curve was 0.782 for LC, 0.725 for SDC, 0.861 for dROCS/DA, and 0.879 for the linear discrimination function that combines dROCS/DA and SDC. CONCLUSIONS: These findings suggest that LC, SDC, and dROCS/DA can be exploited to the discrimination between glaucomatous and normal subjects. LC and SDC seem to arise from the difference in the shape of the contour of dROCS between the groups, suggesting bigger deviations and irregularities in the POAG group.
