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Nurşen Yüksel

Publications and source records attributed to Nurşen Yüksel.

6 recordsLinked to original sources
PubMed2006

Relationship between cognitive impairment and retinal morphological and visual functional abnormalities in Alzheimer disease.

BACKGROUND: There is conflicting evidence as to whether Alzheimer disease (AD) is accompanied by loss of retinal ganglion cells. To evaluate this issue, we have used optical coherence tomography (OCT) to assess the thickness and volume of the retina. We have also sought to correlate our findings with visual function and cognitive impairment. METHODS: We evaluated 28 eyes of 14 patients with AD and 30 eyes of 15 age-matched control subjects. In these two groups, we measured retinal nerve fiber layer (RNFL) thickness, macular thickness, and macular volume with OCT, visual function through latency of the pattern visual evoked potential (VEP) signal, and cognitive impairment through the Mini-Mental State Examination (MMSE). RESULTS: The parapapillary and macular RNFL thickness in all quadrants and positions of AD patients were thinner than in control subjects. The mean total macular volume of AD patients was significantly reduced as compared with control subjects (P < 0.05). Total macular volume and MMSE scores were significantly correlated. No significant difference was found in the latency of the VEP P100 of AD patients and control subjects. CONCLUSIONS: Our study confirms some other studies in showing that in AD patients there is a reduction of parapapillary and macular RNFL thickness and macular volume as measured by OCT. The reduction in macular volume was related to the severity of cognitive impairment.

Aged↗
PubMed2006

Magnetic resonance imaging of the brain in patients with pseudoexfoliation syndrome and glaucoma.

PURPOSE: To evaluate ischemic changes in brain magnetic resonance images in patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) and compare them with age- and sex-matched control subjects. METHODS: This case-control study involved 16 consecutive patients with PXS, 21 patients with PXG and 18 healthy age- and sex-matched control subjects. Each subject underwent a comprehensive ophthalmological examination. In all participants, an axial T(1)-, T(2)- and proton-density-weighted and coronal cerebral 1.5-tesla magnetic resonance imaging (MRI) scan was made. White matter hyperintensities (WMH) were considered present if these were hyperintense on both proton-density- and T(2)-weighted images and not hypointense on T(1)-weighted images. White matter lesions were classified into two parts as the subcortical and periventricular regions. We used a validated rating scale of subcortical WMH: 0 = absent, 1 = punctuate foci, 2 = beginning confluence of foci and 3 = large confluent areas. Periventricular white matter lesions were classified on a scale of 0 (no white matter lesions), 1 (pencil-thin periventricular lining), 2 (thick lining) or 3 (large confluent white matter lesions). RESULTS: The proportions of persons with WMH were 93.7% for patients with PXS, 95.2% for patients with PXG and 55.5% for control subjects. The numbers of white matter lesions in patients with PXS and PXG were significantly greater than in the control subjects (p < 0.05). White matter lesions at subcortical locations in patients with PXG were significantly more frequent than in the control subjects (80.9 vs. 33.3%; p < 0.05). The proportion of patients with subcortical WMH was 56.2% in PXS; no significant difference was found in subcortical WMH between PXS and controls. The proportions of patients with periventricular WMH were 93% in PXS, 90.4% in PXG and 44.4% in controls. White matter lesions at periventricular locations in patients with PXG and PXS were significantly more frequent than in the control subjects (p < 0.05). The difference between the pseudoexfoliation groups and controls with regard to the size of periventricular and subcortical white matter lesions was statically significant (p < 0.05). When patients with PXS were compared with PXG patients, there was no statistically significant difference in the number, size and scale of white matter lesions. CONCLUSION: We found a significantly higher prevalence of MRI-defined WMH in patients with a clinical diagnosis of pseudoexfoliation with or without glaucoma versus control subjects. We think that the findings in this study may shed light on a possible link between ischemic brain lesions and pseudoexfoliation, which is not related with the presence of glaucomatous optic neuropathy. Further investigations are required to resolve the underlying associations.

Aged↗
PubMed2005

Homocysteine and nitric oxide levels in plasma of patients with pseudoexfoliation syndrome, pseudoexfoliation glaucoma, and primary open-angle glaucoma.

PURPOSE: To evaluate plasma total homocysteine (tHcy) and nitric oxide (NO) marker levels in patients with pseudoexfoliation syndrome (PXS), pseudoexfoliation glaucoma (PXG), primary open-angle glaucoma (POAG), and normal controls. METHODS: This cross-sectional, prospective study involved 19 patients with POAG, 18 with PXS, 22 with PXG, and 20 control subjects. Fasting tHcy levels of all study participants were determined using a fluorescence polarization immunoassay method. Quantitation of total nitrate was based on the Griess reaction, in which a chromophore with a strong absorbance at 545 nm is formed by reaction of nitrite with a mixture of naphthylethylenediamine and sulphanilamide. RESULTS: The mean plasma homocysteine level was statistically significantly elevated in the PXS (p=0.033) and the PXG (p=0.023) groups but not in the POAG group (p=0.996) when compared with the control group. Multiple logistic regression analyses comparing the various patient groups with the single control group indicated that elevation in plasma homocysteine concentration was a significant risk factor for PXS (odds ratio per 1 micromol/l increase in homocysteine concentration=2.05, 95% CI=1.19-3.52) and PXG (odds ratio per 1 micromol/l increase in homocysteine concentration=1.36, 95% CI=1.00-1.85) but was not a significant risk factor for POAG (odds ratio per 1 micromol/l increase in homocysteine concentration=0.99, 95% CI=0.78-1.26). NO markers levels were found to be slightly higher in PXS and PXG patients than control and POAG patients but the differences were not statistically significant (p=0.151). Multiple logistic regression analyses comparing the various patient groups with the single control group indicated that elevation in NO marker concentration was not a significant risk factor for PXS (odds ratio per 1 micromol/l increase in NO concentration=1.00, 95% CI=0.99-1.01), PXG (odds ratio per 1 micromol/l increase in NO concentration=1.00, 95% CI=0.99-1.00) and POAG (odds ratio per 1 micromol/l increase in NO concentration=0.99, 95% CI=0.99-1.00). No statistically significant correlations were observed between plasma tHcy and NO markers in study groups (p>0.05). CONCLUSION: Elevated levels of homocysteine in pseudoexfoliation patients with and without glaucoma may partly explain the increased risk of vascular disease among patients with pseudoexfoliation. No significant difference was found in plasma NO markers among the POAG, PXS, PXG, and the control subjects.

Aged↗
PubMedDate not supplied

A comparison of the short-term hypotensive effects and side effects of unilateral brimonidine and apraclonidine in patients with elevated intraocular pressure.

PURPOSE: To compare the short-term ocular hypotensive efficacy and side effects of 0.2% brimonidine and 0.5% apraclonidine in patients with elevated intraocular pressure (IOP). METHODS: We performed a double-masked, placebo-controlled study to compare the efficacy of the application of 0.2% brimonidine and 0.5% apraclonidine for the effect of IOP, systemic blood pressure and heart rate in 20 newly diagnosed ocular hypertensive patients. Effects on the untreated fellow eye and ocular side effects were also determined. All measurements were performed 1, 2, 4, 6 and 8 h after the instillation of one drop. RESULTS: Brimonidine and apraclonidine significantly reduced IOP from baseline at all observation times. No significant difference was observed between the treatment groups. IOP decreased significantly in the untreated fellow eye in the brimonidine group at 4-, 6- and 8-hour checks and at 6-hour checks in the apraclonidine group when compared with placebo. Blood pressure and heart rate decreased significantly in the brimonidine group compared with placebo. Apraclonidine did not affect blood pressure or heart rate any differently than placebo. The pupil diameter and the interpalpebral fissure width significantly increased in the apraclonidine group, but not in the brimonidine group. There were no significant differences in the overall incidence of foreign body sensation, burning and stinging and dry mouth in the treatment groups. CONCLUSIONS: In the short-term, brimonidine was effective in reducing IOP in patients with elevated IOP and was equivalent in efficacy to apraclonidine. On the other hand, a significant change in blood pressure and heart rate was observed with brimonidine; there was no change at all in the apraclonidine group.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

The effects of menopause and hormone replacement therapy on quality and quantity of tear, intraocular pressure and ocular blood flow.

OBJECTIVE: To evaluate the effects of menopause and hormone replacement therapy (HRT) on the quality and amount of tear, intraocular pressure (IOP) and retrobulbar blood flow velocities. PATIENTS AND METHODS: Twenty women aged between 40 and 50 years, free of ocular and systemic diseases and planning to receive HRT were recruited as the study group. Twenty-four healthy, age-matched but still menstruating women were enrolled as controls. On the first day of study basal and reflex Schirmer test, tear break-up time and IOP measurements (at 08.00, 12.00 and 16.00 h) were performed for all groups. On the second day of the study, the peak systolic velocity (PSV), end diastolic velocity (EDV) and resistivity index (RI) of the ophthalmic (OA), central retinal (CRA), nasal (NSPCA) and temporal short posterior ciliary (TSPCA) arteries were determined by color Doppler imaging. The menopausal group received HRT for 2 months, when all measurements were repeated for the 15 women who had received HRT on a daily basis. RESULTS: The quality and amount of tear decreased (p < 0.01), IOP (p < 0.01) and RI of the CRA, TPCA and NPCA (p < 0.05) increased in postmenopausal women compared with the control group. After 2 months of HRT, the quality and amount of tear had increased (p < 0.001) and the IOP had decreased (p < 0.001). The PSV of the CRA and TSPCA had decreased (p < 0.05), as had the RI in the CRA (p < 0.001), NSPCA and TSPCA (p < 0.05). CONCLUSION: We conclude that age-induced changes on quality and amount of tear, IOP and retrobulbar blood flow are intensified by the menopause and that it may be possible to decrease the menopausal effects on these parameters by HRT.

Adult↗