Role of Oxidative Stress in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

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.

Three Single Nucleotide Polymorphisms of LOXL1' in a Turkish Population with Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma.

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.

A rare association of intravitreal bevacizumab injection with double ridge formation in retinopathy of prematurity.

A second anterior ridge formed 8 weeks after therapy in a case of zone II, stage 3 retinopathy of prematurity, which was treated with intravitreal bevacizumab injection alone. The clinical appearance was defined as "double ridge." Retinopathy of prematurity cases treated only with intravitreal bevacizumab injections may progress; therefore, close follow-up is recommended.

Cardiovascular involvement in patients with pseudoexfoliation syndrome.

AIM: Pseudoexfoliation (PEX) syndrome, diagnosed by ocular examination, is a common disorder of the extracellular matrix. Previous studies have demonstrated accumulation of PEX material in the walls of blood vessels and myocardium. We aimed to investigate whether PEX is associated with cardiovascular involvement using carotid ultrasound measurements and myocardial tissue Doppler imaging (TDI). METHODS: Thirty-six PEX patients and 34 age-matched and sex-matched healthy controls who had no PEX material were included. Fasting blood samples were taken and the following data were obtained from all cases: myocardial TDI measurements, the mean carotid intima-media thickness (IMT), total carotid plaque area and number. RESULTS: There were no significant differences between the groups regarding clinical and biochemical data. The peak systolic TDI velocities at the septal (septal S) and lateral annuli (lateral S), and the isovolumic contraction velocity at the lateral annulus [lateral isovolumic contraction velocity (IVC)] were significantly lower in patients with PEX, than in controls (P = 0.001, <0.001 and 0.016, respectively) whereas IMT, total carotid plaque area and number were significantly higher (P = 0.002, 0.035 and 0.033, respectively). In a logistic regression analysis including age, septal S, lateral S, lateral IVC, IMT, total carotid plaque area and number, septal S, lateral S and IMT were significantly associated with PEX, (P = 0.035, 0.011 and 0.035, respectively). CONCLUSION: Peak systolic TDI velocities were significantly lower and IMT was significantly increased in patients with PEX. However, PEX was weakly associated with carotid plaque measurements.