14 results on '"Onur Ozalp"'
Search Results
2. A peek at the window from the eye into the brain: potential use of OCT angiography in dementia
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Semih Ceylan, Eray Atalay, and Onur Ozalp
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Ophthalmology ,Biomedical Engineering ,Optometry - Published
- 2022
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3. Biometric Determinants of Epithelial Thickness Profile Across a Wide Range of Refractive Errors
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Eray Atalay and Onur Ozalp
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Ophthalmology - Abstract
To evaluate the corneal epithelial thickness (CET) profiles and their correlations with axial length (AL) and anterior corneal radius of curvature (Rm F) across different refractive error groups.A total of 1225 eyes of 616 normal patients were included. CET mapping, AL, and Rm F were obtained using spectral-domain optical coherence tomography, optical biometry, and Scheimpflug corneal tomography, respectively. In the CET map, one central (2 mm), eight paracentral (2-5 mm), and eight peripheral (5-6 mm) quadrants were evaluated separately. The subjects were divided into four groups based on their refractive status: hyperopia (spherical equivalent [SE] ≥ +0.50 D), emmetropia (SE -0.50 D and +0.50 D), low myopia (SE ≤ -0.50 D and -3.0 D), and moderate-high myopia (SE ≤ -3.0 D) groups. Linear mixed model analysis with Bonferroni correction was used to compare CET according to refractive error groups. The correlations between the CET profile and the AL and Rm F were analyzed.The central CET was 53.7 ± 3.3 μm in hyperopia (n = 34), 53.2 ± 2.9 μm in emmetropia (n = 353), 52.8 ± 2.9 μm in low myopia (n = 677), and 52.0 ± 3.1 μm in moderate-high myopia (n = 161). Although thinning was observed in CET in all quadrants from hyperopia to moderate-high myopia, it was only significant in the superior and superonasal quadrants at the 2-5 mm and 5-6 mm-diameter rings. While AL and CET were significantly positively correlated (r range 0.17-0.28) in the moderate-high myopia group, Rm F and CET were significantly positively correlated (r range 0.08-0.10) in the low and moderate-high myopia groups.CET varied according to different refractive error groups and was positively correlated with AL and Rm F, particularly in the moderate-high myopia group.
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- 2022
4. COVID-19-related Secondary Bacterial Infections in Intubated Critical Illness
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Derya Tatlısuluoğlu, Gülçin Hilal Alay, Onur Özalp, and Güldem Turan
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ards ,coronavirus ,critical care medicine intubation ,secondary bacterial infection ,Medicine - Abstract
Objective: The prevalence, occurrence, and characteristics of bacterial infection in individuals with severe acute respiratory syndrome coronavirus-2 is primarily unknown. In this research, we examined the effects of secondary bacterial infections (SBI), antibiotic use, and mortality on coronavirus disease-2019 (COVID-19) patients who were observed in intensive care units (ICU) when intubated. Material and Methods: Between October 1, 2020 and February 1, 2021, patients who were monitored because of COVID-19 in adult ICUs at tertiary healthcare facilities were included in this retrospective research. The study included The study included a total of 170 individuals with acute respiratory distress syndrome and COVID-19 pneumonia. Results: Antibiotics were given to 154 (90.58%) patients. While all SBI-positive patients received antibiotic treatment, 78 (45.88%) SBI-negative patients were also treated. In addition, SBI-positive patients had a higher mortality rate (p
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- 2023
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5. A case with acute angle closure glaucoma misdiagnosed as herpetic keratouveitis
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Tulay SIMSEK and Onur OZALP
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- 2020
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6. The Effect of Extensively Drug-resistant Infections on Mortality in Surgical Intensive Care Patients
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Helin Sahinturk, Pinar Zeyneloglu, Onur Ozalp, Fatma Kılıç, Aycan Ozdemirkan, Hande Arslan, and Arash Pirat
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medicine.medical_specialty ,Surgical Intensive Care ,business.industry ,lcsh:R ,Extensively drug-resistant ,lcsh:Medical emergencies. Critical care. Intensive care. First aid ,lcsh:Medicine ,lcsh:RC86-88.9 ,Drug resistance ,Surgical intensive care unit ,medicine ,Mortality ,Intensive care medicine ,business - Abstract
Objective: The aim of the study was to assess the outcomes of intensive care unit acquired extensively drug-resistant (XDR) bacterial infections in a surgical patient cohort. Materials and Methods: The data of patients with XDR bacteria isolated at Baskent University Hospital, Anesthesia and Surgical Intensive Care Unit between January 2016 and December 2016 were reviewed retrospectively. Adult patients over 18 years of age who had undergone surgery within the first 24 hours and who developed intensive care unit infection 48 hours after admission to intensive care unit were included in the study. Results: All of the 341 patients who admitted to the surgical intensive care unit during the study period were underwent surgery within the first 24 hours. XDR bacterial infections were isolated in 30 out (9%) of these 341 patients. The mean APACHE II score was calculated as 18.5 +/- 5.3, and expected mean mortality rate of 35 +/- 17.1. The mean length of intensive care unit stay was 27.0 +/- 27.4 days, while the mean hospital stay was 49.0 +/- 34.3 days. The hospital mortality rate was found to be 57% (n=7). Conclusion: As a conclusion of our study, we found that XDR bacterial infections were common (9%) among intensive care surgical patients and their mortality rate was higher than their expected mortality rate according to their APACHE II scores calculated during intensive care unit admission (57% vs. 35%, respectively).
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- 2018
7. Candidaemia among Adult Solid Organ Transplant Recipients
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Hande Arslan, Özlem Kurt Azap, Melike Hamiyet Demirkaya, Ayşegül Yeşilkaya, Ebru H. Ayvazoglu Soy, Onur Ozalp, and Mehmet Haberal
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Transplantation ,medicine.medical_specialty ,business.industry ,Internal medicine ,Medicine ,business ,Solid organ transplantation - Published
- 2018
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8. Screening of Recipients Prior to Liver and Heart Transplantation
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Mehmet Haberal, Onur Ozalp, Hande Arslan, Özlem Kurt Azap, Melike Hamiyet Demirkaya, and Ayşegül Yeşilkaya
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Heart transplantation ,Vaccination ,Transplantation ,medicine.medical_specialty ,Transplant surgery ,business.industry ,medicine.medical_treatment ,Medical record ,Emergency medicine ,Medicine ,business - Abstract
IntroductionOur purpose was to screen liver and heart recipients for endemic infectious diseases and to organize vaccination recommendations prior to transplant surgery to minimize infections.Materials and MethodsThe data of this report were collected from medical records for each adult candidates o
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- 2018
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9. Investigation of the Role of Convolutional Neural Network Architectures in the Diagnosis of Glaucoma using Color Fundus Photography
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Eray Atalay, Onur Özalp, Özer Can Devecioğlu, Hakika Erdoğan, Türker İnce, and Nilgün Yıldırım
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glaucoma ,convolutional neural network ,artificial intelligence ,telemedicine ,Medicine ,Ophthalmology ,RE1-994 - Abstract
Objectives:To evaluate the performance of convolutional neural network (CNN) architectures to distinguish eyes with glaucoma from normal eyes.Materials and Methods:A total of 9,950 fundus photographs of 5,388 patients from the database of Eskişehir Osmangazi University Faculty of Medicine Ophthalmology Clinic were labelled as glaucoma, glaucoma suspect, or normal by three different experienced ophthalmologists. The categorized fundus photographs were evaluated using a state-of-the-art two-dimensional CNN and compared with deep residual networks (ResNet) and very deep neural networks (VGG). The accuracy, sensitivity, and specificity of glaucoma detection with the different algorithms were evaluated using a dataset of 238 normal and 320 glaucomatous fundus photographs. For the detection of suspected glaucoma, ResNet-101 architectures were tested with a data set of 170 normal, 170 glaucoma, and 167 glaucoma-suspect fundus photographs.Results:Accuracy, sensitivity, and specificity in detecting glaucoma were 96.2%, 99.5%, and 93.7% with ResNet-50; 97.4%, 97.8%, and 97.1% with ResNet-101; 98.9%, 100%, and 98.1% with VGG-19, and 99.4%, 100%, and 99% with the 2D CNN, respectively. Accuracy, sensitivity, and specificity values in distinguishing glaucoma suspects from normal eyes were 62%, 68%, and 56% and those for differentiating glaucoma from suspected glaucoma were 92%, 81%, and 97%, respectively. While 55 photographs could be evaluated in 2 seconds with CNN, a clinician spent an average of 24.2 seconds to evaluate a single photograph.Conclusion:An appropriately designed and trained CNN was able to distinguish glaucoma with high accuracy even with a small number of fundus photographs.
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- 2022
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10. Superiority of Baseline Biomechanical Properties over Corneal Tomography in Predicting Keratoconus Progression
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Mehmet Akif Erol, Eray Atalay, Onur Özalp, Abdullah Divarcı, and Nilgün Yıldırım
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keratoconus ,progression ,ora ,biomechanics ,tomography ,topography ,Medicine ,Ophthalmology ,RE1-994 - Abstract
Objectives:To determine corneal biomechanical and tomographic factors associated with keratoconus (KC) progression.Materials and Methods:This study included 111 eyes of 111 KC patients who were followed-up for at least 1 year. Progression was defined as the presence of progressive change between the first two consecutive baseline visits in any single parameter (A, B, or C) ≥95% confidence interval or two parameters ≥80% confidence interval for the KC population evaluated by the Belin ABCD progression display. The eye with better initial tomographic findings was chosen as the study eye. Analyzed Pentacam parameters were maximum keratometry (Kmax), minimum pachymetry (Kmin), central corneal thickness, thinnest corneal thickness, 90° vertical anterior and posterior coma data in Zernike analysis, and Belin Ambrosio Enhanced Ectasia Display Final D value. Corneal hysteresis (CH) and corneal resistance factor (CRF) were analyzed together with the waveform parameters obtained with Ocular Response Analyzer (ORA). Factors related to KC progression were evaluated using t-tests and logistic regression tests. Statistical significance was accepted as p
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- 2021
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11. Distribution of Microbial Keratitis After Penetrating Keratoplasty According to Early and Late Postoperative Periods
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Onur Özalp, Eray Atalay, Zülfiye Köktaş, and Nilgün Yıldırım
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microbial keratitis ,penetrating keratoplasty ,keratitis ,Medicine ,Ophthalmology ,RE1-994 - Abstract
Objectives:The aim of this study was to investigate the distribution of microbial agents in the early and late postoperative periods in patients with microbial keratitis (MK) after penetrating keratoplasty (PK).Materials and Methods:The records of 36 patients who were clinically diagnosed as having MK after PK were retrospectively reviewed. Culture results were obtained from microbiology records and the organisms that were produced were noted. A case was deemed as viral keratitis based on the clinical appearance, negative cultures, and response to antiviral treatment. Keratitis development times were evaluated in 2 categories: early (within the first year) and late (after year 1) postoperative period. Mann-Whitney U and Kruskal-Wallis tests were used to compare numerical variables that did not show normal distribution and chi-square test was used to compare categorical variables.Results:The majority of MK cases were of bacterial origin (55.5%, n=20), followed by viral (41.7%, n=15) and fungal (2.8%, n=1). Of the 15 cases of early postoperative MK, 10 were bacterial, 4 were viral, and 1 was fungal; however, among cases of late postoperative MK, 10 were bacterial and 11 were viral. The majority (65%) of early and late bacterial infections were caused by gram-positive strains (most commonly staphylococci). Gram-positive bacteria caused keratitis significantly earlier than gram-negative bacteria (p=0.037). Viral and gram-negative bacterial MK was more frequent in the late postoperative period, but the difference was not statistically significant.Conclusion:In our study, bacterial keratitis was more common in post-keratoplasty MK than viral and fungal keratitis. Gram-positive bacteria were the most common causative agents. The increased incidence of gram-negative bacterial agents and viral keratitis in the late postoperative period can be explained by long-term topical steroid use.
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- 2020
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12. Assessment of Phosphate and Osmolarity Levels in Chronically Administered Eye Drops
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Onur Özalp, Eray Atalay, İbrahim Özkan Alataş, Zeynep Küskü Kiraz, and Nilgün Yıldırım
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Phosphate ,eye drops ,osmolarity ,corneal calcification ,Medicine ,Ophthalmology ,RE1-994 - Abstract
Objectives:To assess phosphate and osmolarity levels of chronically administered eye drops commercially available in Turkey.Materials and Methods:A total of 53 topical eye drops including 18 antiglaucoma drugs, 4 nonsteroidal anti-inflammatory drugs (NSAIDs), 10 corticosteroids, 7 antihistaminics, and 14 artificial tears identified using the Vademecum Modern Medications Guideline (2018) were included in the study. Phosphate levels were assessed using Roche Cobas C501 analyzer (Roche Diagnostics GmbH, Mannheim, Germany) and the respective kits. Osmolarity was assessed using Vescor Vapro 5600 vapor pressure osmometer (Sanova Medical Systems, Vienna, Austria). Mean phosphate and osmolarity levels were obtained after averaging three measurements. Eye drops were categorized as isoosmolar, hypoosmolar and hyperosmolar based on physiologic tear osmolarity range (296.5±9.8 mOsm/L).Results:The highest phosphate concentration was found in the antiglaucoma group (20.3±35.4 mmol/L), followed by antihistaminics (17.3±17.9 mmol/L), corticosteroids (15.2±19.1 mmol/L), artificial tears (0.8±1.0), and NSAIDs (0.04±0.08). Percentage of medications in the hyperosmolar category was highest in the NSAI group (75%), followed by antihistaminics (43%), corticosteroids (20%), and antiglaucoma drugs (19%). Nearly all of the artificial tear formulations were in the hypoosmolar (71%) or isoosmolar (21%) categories.Conclusion:Approximately 40% of glaucoma medications and approximately 60% of corticosteroid and antihistaminic medications had a phosphate concentration higher than the physiologic tear phosphate level (1.45 mmol/L).
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- 2019
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13. Advances in the diagnosis and treatment of keratoconus
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Eray Atalay, Onur Özalp, and Nilgün Yıldırım
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Ophthalmology ,RE1-994 - Abstract
Keratoconus had traditionally been considered a rare disease at a time when the imaging technology was inept in detecting subtle manifestations, resulting in more severe disease at presentation. The increased demand for refractive surgery in recent years also made it essential to more effectively detect keratoconus before attempting any ablative procedure. Consequently, the armamentarium of tools that can be used to diagnose and treat keratoconus has significantly expanded. The advances in imaging technology have allowed clinicians and researchers alike to visualize the cornea layer by layer looking for any early changes that might be indicative of keratoconus. In addition to the conventional geometrical evaluation, efforts are also underway to enable spatially resolved corneal biomechanical evaluation. Artificial intelligence has been exploited in a multitude of ways to enhance diagnostic efficiency and to guide treatment. As for treatment, corneal cross-linking treatment remains the mainstay preventive approach, yet the current main focus of research is on increasing oxygen availability and developing new strategies to improve riboflavin permeability during the procedure. Some new combined protocols are being proposed to simultaneously halt keratoconus progression and correct refractive error. Bowman layer transplantation and additive keratoplasty are newly emerging alternatives to conventional keratoplasty techniques that are used in keratoconus surgery. Advances in tissue engineering and regenerative therapy might bring new perspectives for treatment at the cellular level and hence obviate the need for invasive surgeries. In this review, we describe the advances in the diagnosis and treatment of keratoconus primarily focusing on newly emerging approaches and strategies.
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- 2021
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14. The Relationship Between Vasoproliferative Tumor and Uveitis in a Multiple Sclerosis Patient: A Case Report and Review of the Literature
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Onur Özalp, Eray Atalay, Mustafa Değer Bilgeç, Nazmiye Erol, and Nilgün Yıldırım
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vasoproliferative tumor ,cryotherapy ,uveitis ,multiple sclerosis ,Medicine ,Ophthalmology ,RE1-994 - Abstract
Vasoproliferative retinal tumor (VPRT) is a rare, benign lesion with a variable clinical course depending on the individual. Favorable outcomes are obtained with early diagnosis and treatment of patients with VPRT. In this case report, we present a case of concomitant VPRT and multiple sclerosis along with our management of uveitis and secondary glaucoma that presumably developed following cryotherapy for VPRT.
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- 2019
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