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Dive into the research topics where Oguzhan Saygili is active.

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Featured researches published by Oguzhan Saygili.


Journal of Cataract and Refractive Surgery | 2008

Comparison of in vitro safety profiles of vancomycin and cefuroxime on human corneal endothelial cells for intracameral use

Efdal Yoeruek; Martin S. Spitzer; Oguzhan Saygili; Olcay Tatar; Tilo Biedermann; Erdal Yoeruek; Karl U. Bartz-Schmidt; Peter Szurman

PURPOSE: To evaluate and compare the cytotoxic and apoptotic properties of cefuroxime and vancomycin on cultured human corneal endothelial cells (HCECs) to determine their safety for intracameral use. METHODS: Human corneal endothelial cells were harvested from human donor eyes and exposed to various concentrations of cefuroxime and vancomycin (0.15 to 15 mg/mL). For cytotoxicity testing, the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) test was performed. Annexin V binding combined with propidium iodide (PI) co‐staining was used for the distinction of viable, early, and late apoptotic cells. Odds ratios (ORs) and confidence intervals were calculated for the control group (without drug exposure) for 2.75 mg/mL and 15 mg/mL. Cell morphology and immunolocalization of zonula occludens 1 (ZO1) were assessed after 24 hours of drug exposure. RESULTS: Reduction in cell viability was observed in a dose‐dependent manner after exposure to both drugs. Cefuroxime concentrations higher than 2.75 mg/mL and vancomycin concentrations higher than 5.0 mg/mL led to significant reduction in cell viability. The mean number of annexin V–positive and PI‐positive cells was not significantly increased at 2.75 mg/mL for either antibiotic agent. After exposure to 15.0 mg/mL, however, the late apoptotic/necrotic cells predominated, with higher ORs indicating accelerated cell death. Increasing concentrations of both antibiotic agents resulted in fading immunopositivity for ZO1. CONCLUSIONS: These data suggest a dose‐dependent toxicity of cefuroxime and vancomycin on HCECs in vitro with a narrow range of safety. Although the clinically used concentrations seem to be safe, slightly higher concentrations might induce irreversible cell death and thus should be avoided.


Journal of Clinical Ultrasound | 2009

Effects of intravitreal bevacizumab (Avastin®) therapy on retrobulbar blood flow parameters in patients with neovascular age‐related macular degeneration

Ahmet Mete; Oguzhan Saygili; Alper Mete; Metin Bayram; Necdet Bekir

To investigate the effects of intravitreal bevacizumab on retrobulbar circulation in patients with neovascular age‐related macular degeneration (AMD).


Cornea | 2009

Human anterior lens capsule as carrier matrix for cultivated human corneal endothelial cells.

Efdal Yoeruek; Oguzhan Saygili; Martin S. Spitzer; Olcay Tatar; Karl U. Bartz-Schmidt; Peter Szurman

Purpose: To evaluate the potential of human anterior lens capsule (HALC) as a carrier matrix for cultivating and transplanting human corneal endothelial cells (HCECs). Methods: HALCs obtained from 12 patients during cataract surgery were exposed to enzyme digestion to dissolve the lens epithelium and were plated with the epithelial side up in 6-well plates. HCECs were harvested from human donor eyes and seeded on HALCs. Cell morphology was assessed with a phase-contrast microscope after 6 hours of incubation and at days 1, 3, 5, and 7. The number of HCECs counted at each capsule was pooled, and the density was expressed as cells per square millimeter after 7 days in culture. Live/Dead viability/cytotoxicity assay was also performed and analyzed by fluorescence microscopy after 7 days of incubation during confluence. Expression of zonula occludens-1, connexin-43, Na+/K+-adenosine triphosphatase, and cytokeratin-3 (AE5) were investigated by immunohistochemistry. Results: Seven days after seeding on HALCs, the HCECs were grown to confluence and formed a continuous viable monolayer with a mean cell density of 3012 ± 109 cells per square millimeter, which mimics native corneal endothelial cells. Immunohistochemistry analysis demonstrated strongly positive staining for AE5, zonula occludens-1, connexin-43, and Na+/K+-adenosine triphosphatase. Conclusions: Cell density and morphology of HCECs on HALCs were similar to those of healthy corneas. Phenotypical properties of HCECs on HALCs imply that the HCEC sheets are capable of maintaining intact barrier and ionic pump functions in vitro. HALCs might, therefore, be recommended as a potential scaffold for ex vivo expansion of HCECs, possibly providing an autologous biologic substrate for therapy of isolated corneal endothelial diseases.


Pediatric Pulmonology | 2011

Unusual presentation: Pulmonary hemosiderosis with celiac disease and retinitis pigmentosa in a child†

Ozlem Keskin; Mehmet Keskin; Elif Güler; Ediz Tutar; Oguzhan Saygili; Ercan Kucukosmanoglu; Yılmaz Kör; Haydar Celik; Enes Coskun

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease characterized by anemia, hemoptysis and recurrent alveolar hemorrhage. The combination of IPH and celiac disease (CD) is extremely rare. We report a 9‐year‐old boy with Lane‐Hamilton syndrome, co‐occurrence of pulmonary hemosiderosis with CD. This presentation is unique presentation because he has also retinal pigmentation. Pediatr. Pulmonol. 2011; 46:820–823.


European Journal of Ophthalmology | 2010

Long-term visual acuity and its predictors after cataract surgery in patients with uveitis.

Efdal Yoeruek; Christoph Deuter; Sylvia Gieselmann; Oguzhan Saygili; Martin S. Spitzer; Olcay Tatar; Karl U. Bartz-Schmidt; Peter Szurman

Purpose. To analyze the outcomes of phacoemulsification and posterior intraocular lens (IOL) implantation in patients with uveitis and to determine factors responsible for poor visual outcome. Methods. The records of 155 patients (180 eyes) with uveitis who had phacoemulsification and IOL implantation between August 2001 and March 2008 were examined retrospectively. Best-corrected visual acuity (BCVA) was recorded at the immediate preoperative visit and at follow-up examinations every 3 months. At each postoperative visit, a complete ophthalmologic examination was performed. The postoperative visual outcomes and complications were analyzed. Univariate regression analysis was done to determine risk factors for poor visual acuity during follow-up. Results. The mean follow-up was 31.4 months (range 3–78 months). An underlying systemic disease was present in 70 (45.2%) patients (82 eyes, 45.6%). The mean preoperative logMAR BCVA was 1.13±0.62 (95% CI: 0.85–1.02) and increased to 0.42±0.57 (95% CI: 0.32–0.59) at last medical visit (p<0.001). A total of 107 eyes (59.4%) had postoperative complications including posterior capsular opacification, newly developed macular edema, recurrence of uveitis, macular epiretinal membrane, and deposits on the IOL surface. Preoperatively observed macular lesions was the factor most strongly associated with poor visual outcome after cataract surgery (odds ratio: 5.43; 95% CI: 3.41–7.34; p<0.001). Anterior segment pathologies, age at surgery, etiology of uveitis (idiopathic, uveitis associated systemic disease), and gender did not influence visual rehabilitation after surgery (p>0.05). Conclusions. The outcomes of phacoemulsification and IOL implantation in patients with uveitis were satisfactory. Patients with observed preoperative macular lesions are at risk for poor visual outcome.


Ophthalmic Research | 2012

Does Ranibizumab (Lucentis®) Change Retrobulbar Blood Flow in Patients with Neovascular Age-Related Macular Degeneration?

Mete A; Oguzhan Saygili; Kıvanç Güngör; Bayram M; Necdet Bekir

Purpose: To investigate the effects of intravitreal ranibizumab on retrobulbar blood flow in patients with neovascular age-related macular degeneration (AMD). Methods:Thirty-one eyes of 30 patients with neovascular AMD were examined prospectively by both color Doppler imaging and fundus fluorescein angiography. Color Doppler imaging was used to measure the maximum and minimum velocities of the central retinal vein, peak systolic/end-diastolic velocities of blood flows, and pulsatility index and resistivity index values in the central retinal artery, nasal/temporal posterior ciliary arteries (NPCA/TPCA) and ophthalmic artery. The t test for paired samples was used for comparing retrobulbar blood flow values before and after intravitreal ranibizumab (Lucentis®) injection in the study and control groups. Results:There was a statistically significant (p < 0.05) difference between the pre-injection and post-injection end-diastolic velocities of the NPCA and TPCA and resistivity index values of TPCA. The other parameters showed no statistically significant difference. Conclusion: Our results show that intravitreal ranibizumab injection increases retrobulbar blood flow.


Ophthalmic Research | 2010

Effects of Bevacizumab on Apoptosis, Na+-K+-Adenosine Triphosphatase and Zonula Occludens 1 Expression on Cultured Corneal Endothelial Cells

Efdal Yoeruek; Olcay Tatar; Martin S. Spitzer; Oguzhan Saygili; Tilo Biedermann; Karl U. Bartz-Schmidt; Sebastian Thaler; Peter Szurman

Background: This laboratory study was undertaken to investigate the influence of bevacizumab on apoptosis, Na+-K+-adenosine triphosphatase (Na+-K+-ATPase) and zonula occludens 1 (ZO-1) expression on cultured human corneal endothelial cells (HCECs). Methods: Annexin V binding combined with propidium iodide (PI) costaining was used to distinguish viable, early and late apoptotic cells. Immunolocalization of ZO-1 and Na+-K+-ATPase was performed to analyze intercellular cell integrity after exposure to 5.0 mg/ml bevacizumab for 24 h. Results: No significant induction of apoptosis or necrosis was seen in HCECs after exposure to 5.0 mg/ml bevacizumab (p = 0.689, p = 0.516, respectively). The mean number of annexin-V-FITC- and PI-positive cells did not change significantly. Additionally, no significant changes in expression were detectable, neither for ZO-1 nor for Na+-K+-ATPase in comparison with the control. For ZO-1, 70.0% of the cells stained intensely, 24.7% stained moderately, and 5.3% stained weakly in the control group. After exposure to 5.0 mg bevacizumab, only minor changes were observable: 68.8% stained intensely, 25.4% moderately and 5.8% weakly (p = 0.524). For Na+-K+-ATPase, 19.3% of the cells stained intensely, 59.4% moderately, and 21.3% weakly in the control group. After exposure to 5.0 mg bevacizumab, again only minor changes were observable in the expression pattern: 18.2% stained intensely, 60.3% moderately and 21.5% weakly. The changes were not significant compared with the control (p = 0.492). Conclusions: Bevacizumab, at concentrations used clinically, did not induce apoptosis or necrosis in HCECs in vitro. Additionally, no alteration of ZO-1 or Na+/K+-ATPase expression was detected after exposure to 5.0 mg/ml bevacizumab for 24 h.


Seminars in Ophthalmology | 2017

Maximal Levator Muscle Resection for Primary Congenital Blepharoptosis with Poor Levator Function

Alper Mete; Halil Hüseyin Çağatay; Can Pamukcu; Sabit Kimyon; Oguzhan Saygili; Kıvanç Güngör

ABSTRACT Purpose: To evaluate the clinical outcomes of maximal levator muscle resection surgery in patients with poor levator function. Methods: This prospective study included 29 eyelids of 23 patients who underwent maximal levator resection surgery. Pre- and postoperatively, all patients’ routine ophthalmic examination including evaluation of upper eyelid skin crease positions; levator muscle function (LF), rima palpebrarum (RP), and margin-reflex distance (MRD) measurements were recorded. Outcome was considered successful when the difference between the two upper eyelids was ≤1 mm; if the difference between the two eyelid margins was more than 1 mm and less than 2 mm, it was considered to be satisfactory. More than 2 mm difference was considered to be poor. Results: Mean patient age was 11.3 ± 8.6 years (3 months to 24 years). Mean follow-up time was 22.8 ± 6.9 months (10 to 36 months). Preoperatively mean RP, MRD, and LF measurements were 5.5 ± 1.7 mm, −0.14 ± 1.6 mm, 2.5 ± 1.4 mm (0–4 mm), respectively. Preoperatively, eight (27,6%) patients had skin crease. Abnormal head posture was detected in eight (34.8%) of the patients. Postoperatively, RP, MRD, and LF values increased significantly (p < 0.05). Mean RP, MRD, and LF measurements were 8.3 ± 1.5 mm, 2.6 ± 1.2 mm, 5.1 ± 2.1 mm, respectively. Fourteen subjects (60.9%) had successful results, two subjects (8.7%) had satisfactory results, and seven subjects (30.4%) had poor results. Abnormal head postures of all patients were resolved. Conclusions: Maximal levator resection may be a good alternative method to frontalis suspension in congenital blepharoptosis patients with poor levator function.


Wiener Klinische Wochenschrift | 2016

The effects of Nigella sativa oil, thymoquinone, propolis, and caffeic acid phenethyl ester on radiation-induced cataract

Elif Demir; Seyithan Taysi; Behcet Al; Tuncer Demir; Seydi Okumus; Oguzhan Saygili; Edibe Saricicek; Ahmet Dirier; Muslum Akan; Mehmet Tarakcioglu; Cahit Bagci

SummaryBackgroundThe aim of this study was to investigate the antioxidant and radioprotective effects of propolis, caffeic acid phenethyl ester (CAPE), Nigella sativa oil (NSO), and thymoquinone (TQ) against ionizing radiation-induced cataracts in lens after total cranium irradiation of rats with single dose of 5-Gy cobalt-60 gamma rays.MethodsA total of 74 Sprague–Dawley rats were divided into 8 groups to test the radioprotective effectiveness of Nigella sativa oil, thymoquine, propolis, or caffeic acid phenethyl ester administered by either orogastric tube or intraperitoneal injection. Appropriate control groups were also studied.ResultsChylack’s cataract classification was used in the study. At the end of the tenth day, cataracts developed in 80 % of the rats in the radiotherapy group. After irradiation, cataract rate dropped to 20 % in NSO, 30 % in propolis, 40 % in CAPE, and 50 % in TQ groups and was limited to grade 1 and grade 2. Cataract formation was observed the least in NSO group and the most in TQ group. In the irradiated (IR) group, superoxide dismutase activity was lower, while glutathione peroxidase and xanthine oxidase activities and malondialdehyde level were higher compared with the other groups. Total superoxide scavenger activity and nonenzymatic superoxide scavenger activity were not statistically significant in IR group compared with the other groups.ConclusionsThe findings obtained in the study might suggest that propolis, CAPE, NSO, and TQ could prevent cataractogenesis in ionizing radiation-induced cataracts in the lenses of rats, wherein propolis and NSO were found to be more potent.


Pediatric Neurology | 2015

Maternal Iron Deficiency Anemia as a Risk Factor for the Development of Retinopathy of Prematurity.

Alper I. Dai; Seniz Demiryürek; Sefika Nur Aksoy; Peren Perk; Oguzhan Saygili; Kıvanç Güngör

BACKGROUND Retinopathy of prematurity is a proliferative vascular disease affecting premature newborns and occurs during vessel development and maturation. The aim of this study was to evaluate the maternal iron deficiency anemia as possible risk factors associated with the development of retinopathy of prematurity among premature or very low birth weight infants. METHODS In this study, mothers of 254 infants with retinopathy of prematurity were analyzed retrospectively, and their laboratory results of medical records during pregnancy were reviewed for possible iron deficiency anemia. RESULTS In a cohort of 254 mothers of premature infants with retinopathy of prematurity, 187 (73.6%) had iron deficiency, while the remaining 67 (26.4%) mothers had no deficiency. Babies born to mothers with iron deficiency anemia with markedly decreased hemoglobin, hematocrit, mean corpuscular volume, serum iron, and ferritin levels were more likely to develop retinopathy of prematurity. CONCLUSIONS Our results are the first to suggest that maternal iron deficiency is a risk factor for the development of retinopathy of prematurity. Our data suggest that maternal iron supplementation therapy during pregnancy might lower the risk of retinopathy of prematurity.

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Alper Mete

University of Gaziantep

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Sabit Kimyon

University of Gaziantep

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Ahmet Mete

University of Gaziantep

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Necdet Bekir

University of Gaziantep

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Olcay Tatar

University of Gaziantep

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