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    Association of tumour necrosis factor-alpha -308 G/A polymorphism with primary open-angle glaucoma
    (WILEY-BLACKWELL, 2012) Bozkurt, Banu; Mesci, Lutfiye; Irkec, Murat; Ozdag, Burcin B.; Sanal, Ozden; Arslan, Umut; Ersoy, Fugen
    Background: Tumour necrosis factor-alpha (TNF-a) is an important proinflammatory cytokine driving axonal degeneration and retinal ganglion cell apoptosis in glaucoma. The aim of the study was to evaluate the association of TNF-a -308 G/A and -238 G/A polymorphisms with primary open-angle glaucoma (POAG). Design: A prospective, casecontrol study, university hospital setting. Participants: Eighty-six POAG patients and 193 healthy unrelated controls. Methods: TNF-a polymorphisms were screened by using direct gene sequencing. Main Outcome Measures: Frequency of TNF-a -308 G/A and TNF-a -238 G/A promoter polymorphisms in glaucoma and healthy subjects. Results: The frequencies of TNF-a -308 GA genotype and A allele were higher in patients with POAG (22.1% and 12.2%, respectively) in comparison with the control group (10.9% and 6%, respectively) (P = 0.046 and 0.02, respectively), with odds ratios of 2.45 (P = 0.01, 95% CI = 1.234.87) and 2.19 (P = 0.013, 95% CI = 1.184.08), respectively. Genotype distribution of the TNF-a -238 variants did not yield a statistically significant difference between the two groups (P = 0.87). Conclusion: TNF-a -308 G/A polymorphism seems to be associated with POAG in Turkish population. However, population-based studies with large number of subjects and long-term follow-up are needed to verify the association of TNF-a -308 G/A polymorphism with glaucoma susceptibility.
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    Asymmetry in optic disc morphometry as measured by confocal scanning laser ophthalmoscopy in subjects with hyperopic anisometropia
    (SLACK INC, 2008) Bozkurt, Banu; Irkec, Murat; Arslan, Umut
    Purpose: To determine whether there is an asymmetry in optic nerve head morphometry in subjects with hyperopic anisometropia. Methods: Seventeen men and 20 women with a mean age of 31.43 +/- 2.73 (standard error of mean) years underwent a complete eye examination and optic nerve head topography with the Heidelberg Retina Tomograph II (Heidelberg Engineering, GmBH, Heidelberg, Germany). Differences in optic nerve head parameters between anisometropic eyes and fellow eyes were evaluated using the paired-sample t test or Wilcoxon signed rank test and the correlations between refraction, visual acuity, and disc parameters were evaluated with Spearman's correlation coefficient. Results: The median refractive errors of hyperopic anisometropic and fellow eyes were +4 D (range: +2.0 to +7.50 D) and 0 D (range: 0 to +4 D), respectively. The mean best-corrected visual acuity of the amblyopic eyes was 0.43 +/- 0.25. The mean disc area of the anisometropic eyes (1.69 +/- 0.35 mm(2)) was significantly smaller than the fellow eyes (2.01 +/- 0.42 mm(2)) (P < .001). The differences between eyes in mean cup area, rim area, rim volume, and cup shape were statistically significant (P < .05). In aniosmetropic eyes, refractive error (r = -0.406; P = .013) and visual acuity (r = 0.347; P = .035) showed significant correlations with rim area. Conclusion: Hyperopic anisometropia is associated with a remarkable interocular difference in optic disc size and other topographic parameters.
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    Diagnostic Accuracy of Heidelberg Retina Tomograph Iii Classifications in a Turkish Primary Open-Angle Glaucoma Population
    (WILEY-BLACKWELL PUBLISHING, INC, 2010) Bozkurt, Banu; İrkeç, Murat; Arslan, Umut
    Purpose: This study aimed to evaluate the diagnostic accuracy of Moorfields regression analysis (MRA) and the glaucoma probability score (GPS) in primary open-angle glaucoma (POAG) and to measure the level of agreement between the two algorithms in classifying eyes as normal or abnormal in a Turkish population. Methods: We prospectively selected 184 healthy subjects and 158 subjects with POAG, who underwent an ophthalmological examination, visual field analysis and imaging with the Heidelberg Retina Tomograph II, using HRT III software, Version 3.0. The diagnostic accuracies of the two classifications were measured when the borderline was taken as either normal (highest specificity criteria) or abnormal (highest sensitivity criteria). The agreement between them was calculated using the unweighted kappa (kappa) coefficient. Results: Optic nerve head topographic parameters showed statistically significant differences between the control and POAG groups (p < 0.001). The parameters with the highest area under the receiver operating characteristic curves were global GPS (0.86), cup : disc area (0.85), rim : disc area (0.85) and vertical cup : disc (0.85). According to the highest specificity criteria, MRA had a sensitivity of 67.7% and a specificity of 95.1%, whereas the GPS had a sensitivity of 70.9% and a specificity of 88.0%. According to the highest sensitivity criteria, MRA had a sensitivity of 81.0% and a specificity of 75.0%, whereas the GPS had a sensitivity of 89.2% and a specificity of 57.6%. A moderate agreement of 68% (233 eyes) with a kappa coefficient of 0.51 was found between MRA and the GPS. Conclusions: The GPS automated classification showed similar sensitivity to MRA, but considerably lower specificity, when applied in a Turkish population.
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    Evaluation of GDx parameters by using information theory
    (TUBITAK SCIENTIFIC & TECHNICAL RESEARCH COUNCIL TURKEY, 2011) Arslan, Umut; Bozkurt, Banu; Karaagaoglu, Ahmet Ergun; Irkec, Murat Tanju
    Aim: To evaluate the performance of GDx parameters in the diagnosis of glaucoma by using information theory and compare the results obtained using receiver operating characteristic (ROC) curve analysis, which is a traditional method. Materials and methods: Retinal nerve fiber layer thickness was measured in 270 eyes with glaucoma and 81 normal eyes with scanning laser polarimeter (NFA GDx version, 1.0.08), and 14 GDx parameters were calculated. Both ROC curve analysis and information theory were used to determine the best GDx parameters. The best cut-off points of these parameters were obtained using information theory for glaucoma prevalence (Pr) of 1%, 2%, and 5%. Results: The parameters having the maximum information content and discriminatory power are The Number, Ellipse modulation, and Maximum modulation, respectively. The best cut-off points associated with these parameters are 32.08, 1.65, and 1.20 for specified Pr values considered, respectively. The best cut-off value for inferior ratio is 1.95 when Pr is 1% or 2%, whereas the best cut-off point of the parameter is 2.11 when Pr is 5%. Conclusion: Although ROC curve analysis can be used for evaluating the performance of the diagnostic test, it cannot determine the best cut-off point for certain prevalence. Information theory approach seems to be more superior to the traditional ROC curve analysis for tackling this problem.