RESUMEN
Objectives: To investigate the role of oxidative stress on pseudoexfoliation formation and progression from pseudoexfoliation syndrome (XFS) to pseudoexfoliation glaucoma (XFG). Materials and Methods: This study investigated oxidative stress biomarkers in blood samples from 58 patients with XFG, 47 patients with XFS, and 134 healthy age- and sex-matched controls. Results: The highest serum malondialdehyde (MDA) levels were measured in XFG patients (p<0.001), and MDA level was higher in XFS patients than controls (p<0.001). Superoxide dismutase (SOD) and catalase (CAT) enzyme activities were significantly lower in XFS and XFG patients than in the control group, whereas a significant increase was observed in glutathione (GSH) levels (p<0.001 for all). However, levels of these three biomarkers did not differ significantly between XFS and XFG patients (p=0.188, p=0.185, and p=0.733, respectively). Nitric oxide (NO) concentration was significantly lower in XFG patients compared to XFS patients and controls (p<0.001) but did not differ between XFS patients and controls (p=0.476). Conclusion: Elevated MDA levels suggest that lipid peroxidation is important in XFS and XFG development and progression from XFS to XFG. In addition, reduction in SOD and CAT enzyme activities is considered a deficiency in the enzymatic antioxidant protection system. Furthermore, GSH values may be evaluated as a compensatory response to oxidative stress in XFS and XFG. Alterations in NO indicate the role of a vascular regulatory factor in the progression from XFS to glaucoma.
RESUMEN
OBJECTIVES: To investigate the three single nucleotide polymorphisms (SNPs) (rs3825942, rs1048661, and rs2165241) of the LOXL1 gene in pseudoexfoliation syndrome (XFS) and pseudoexfoliation glucoma (XFG) in the Turkish population. MATERIALS AND METHODS: DNA was obtained from blood samples of 48 XFS, 58 XFG, and 171 control subjects. Three LOXL1 SNPs (rs3825942, rs1048661, rs2165241) were investigated with real time PCR, a probe-based genotyping method, and melting curve analysis. RESULTS: All three SNPs of LOXL1 were significantly associated with XFS (rs3825942 p=3.54x10-6, odds ratio [OR]=∞; rs1048661 p=0.008, OR=2.18; rs2165241 p=8.69x10-9, OR=4.30) and XFG (rs3825942 p=3.41x10-7, OR=∞; rs1048661 p=1.75x10-5, OR=3.78; rs2165241 p=3.85x10-11 OR=4.90). No significant differences were observed between the XFS and XFG groups for any of the SNPs. The GG genotype of rs3825942 was more valuable for distinguishing pseudoexfoliative cases from healthy individuals. The homozygous TT genotype of rs2165241 was associated with 6-fold increased XFS risk (p=8.15x10-8, OR=6.32) and 7-fold increased XFG risk (p=1.45x10-10 OR=7.95). The GGT haplotype consisting of all three risk alleles was associated with a 7.45-fold higher risk of XFS/XFG (p=8.65x10-14, OR=7.45). Presence of T allele of rs2165241 conferred 3 times higher risk for men than women (p=6.78x10-5, OR=3.202). CONCLUSION: LOXL1 SNPs are associated with increased risk for pseudoexfoliation in the Turkish population. T allele of rs2165241 was found to be the most important characterized risk factor for our cohort. All SNP distributions were similar to other European and American populations.
RESUMEN
PURPOSE: To report vision screening results among school children in Eskisehir, Turkey. METHODS: Vision screening was performed in 7- to 8-year-old school children in November and December 2011. Best-corrected visual acuity (BCVA) assessment, cover test, and autorefractometer measurement under cycloplegia were performed. Spherical equivalent ≤-0.50 diopters (D) was considered to be myopic, while spherical equivalent >0.75 D was considered to be hypermetropic. Astigmatism was defined as a cylinder power ≥0.75 D. Regression analysis was used to determine the likelihood of having BCVA ≤0.8 Snellen (versus having BCVA >0.8 Snellen) in the presence of independent variables. RESULTS: A total of 709 children were included. The prevalence rates of myopia, hypermetropia, and astigmatism were 22.6%, 10.6%, and 11.0%, respectively. Overall, 145 children (20.4%) needed spectacles, but only 65 of these were wearing them. The prevalence of children who required spectacles for myopia ≤-3.00 D and spectacles for hypermetropia ≥3.00 D were 0.8% and 1.0%, respectively. The prevalence of BCVA ≤ 0.8 Snellen was 56/709 (7.9%). In 39/709 (5.5%) of children, amblyopia was present; strabismus (14/56), isometropia (14/56), and anisometropia (11/56) were the etiologies. Strabismus was diagnosed in 18 children (2.5%). Anisometropia, strabismus, hypermetropia, and astigmatism were associated with BCVA ≤ 0.8 Snellen (odds ratio, OR, 6.32, 39.18, 5.47, 5.17, respectively; p = 0.0001 for all ORs). CONCLUSIONS: Myopia and amblyopia rates in Eskisehir were high among school children. The need for a national large-scale vision screening program for children that includes diverse regions of Turkey is apparent.
