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ÖZDEMİR, MEHMET HAKAN

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MEHMET HAKAN
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ÖZDEMİR
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    PublicationOpen Access
    The choroid and optical coherence tomography
    (2016-01-01) ÖZDEMİR, MEHMET HAKAN; Altinisik, M; SEZER, TAHA; KOYTAK, İBRAHİM ARİF; SEZER, TAHA; KOYTAK, İBRAHİM ARİF; ÖZDEMİR, MEHMET HAKAN
    The choroid is the most vascular tissue in the eye and it plays an important role in the pathophysiology of various common chorioretinal diseases such as central serous retinopathy, age-related macular degeneration and degenerative myopia. Quantitative assessment of the choroid has been quite challenging with traditional imaging modalities such as indocyanine green angiography and ultrasonography due to limited resolution and repeatability. With the advent of optical coherence tomography (OCT) technology, detailed visualization of the choroid in vivo is now possible. Measurements of choroidal thickness have also enabled new directions in research to study normal and pathological processes within the choroid. The aim of the present study is to review the current literature on choroidal imaging using OCT.
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    PublicationOpen Access
    Diffuse Retinal Thickening due to Epiretinal Membrane in a Patient with Idiopathic Parafoveal Telangiectasia
    (2019-01-01T00:00:00Z) HAMZAYEV, IGBAL; ELBAY, AHMET; EKİNCİ, CANSU; Ozdemir, Hakan; HAMZAYEV, IGBAL; ELBAY, AHMET; EKİNCİ, CANSU; ÖZDEMİR, MEHMET HAKAN
    Idiopathic parafoveal telangiectasia (IPT) is characterized by abnormal dilated or ectatic retinal capillaries with exudation. In many studies macular hole or pseudohole was demonstrated in patients with IPT. However, only one case with the coexistence of IPT and epiretinal membrane (ERNI) formation was reported before. In this study, we presented the retinal alterations of a patient with IPT admitted to our clinic with complaint of blurred vision for two months. A hyperreflective band refers to ERM, diffuse thickening and increased reflectance of inner retinal layers and cystic spaces in the inner nuclear layer of the retina were detected in horizontal optic coherence tomography (OCT) images of left eye. Due to the thickening of the inner retinal layers, foveal depression was lost. There was no full-thickness or partial-thickness retinal tissue defect in any OCT scan.
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    PublicationOpen Access
    Autologous Platelet-Rich Fibrin in the Treatment of Refractory Macular Holes
    (2019-11-06T00:00:00Z) Koytak, Arif; NUHOĞLU, FADİME; BAYRAKTAR, HAVVANUR; Ercan, Rukiye; Ozdemir, Hakan; KOYTAK, İBRAHİM ARİF; NUHOĞLU, FADİME; BAYRAKTAR, HAVVANUR; ERCAN, RUKIYE; ÖZDEMİR, MEHMET HAKAN
    Purpose. To describe a novel method for the treatment of refractory macular holes. Methods. Two case reports on the use of autologous platelet rich fibrin (PRF), followed by sulfur hexafluoride gas tamponade to facilitate closure of refractory macular holes. Results. Macular holes were succesfully closed within a week in both cases. Best corrected Snellen visual acuities improved from counting fingers to 0.16 in the first case, and from 0.05 to 0.2 in the second case. No complication occurred during or a er the procedures. Conclusion. e use of autologous PRF seems to be a safe and effective alternative method for the treatment of refractory macular holes. Further experience and studies are required to assess the value of autologous PRF in the management of challenging macular hole cases of different etiologies. To the best of our knowledge, this is the first use of autologous PRF in the treatment of macular holes.
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    PublicationOpen Access
    Extramacular Retinal Hole Following Intravitreal Dexamethasone Implant: Case Report
    (2019-06-27T00:00:00Z) Ekinci, C; Kayıran, A; Özdemir, H; EKİNCİ, CANSU; ÖZDEMİR, MEHMET HAKAN
    The intravitreal dexamethasone implant Ozurdex is indicated for the treatment of macular edema due to diabetes and branch retinal vein occlusion. While the most common ocular side effects are elevated intraocular pressure and cataract formation, rare complications related to the injection have been reported. We present a case with extramacular retinal hole after Ozurdex injection.
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    PublicationOpen Access
    Cilioretinal artery occlusion with paracentral acute middle maculopathy associated with COVID-19
    (2021-07-01T00:00:00Z) Bayram, Nurettin; Ozdemir, Hakan; Ozsaygili, Cemal; ÖZDEMİR, MEHMET HAKAN
    The purpose of the study is to describe cilioretinal artery (CILRA) occlusion that is presumed to be associated with COVID-19 without severe respiratory distress and inform ophthalmologists of unusual ocular presentations of COVID-19. Here, we present the first case of a patient with isolated CILRA occlusion and paracentral acute middle maculopathy (PAMM) after recently polymerase chain reaction-proven COVID-19. A 26-year-old female patient presented with a visual field defect in her left eye for 2 days and decreased vision compared to her right eye. It was learned that the patient had a laboratory-proven COVID-19 infection with mild respiratory symptoms that did not require hospitalization 2 weeks ago. Fundus examination revealed retinal edema in the left eye area supplied by the CILRA. Spectral-domain optical coherence tomography revealed a prominent hyperreflective band at the inner nuclear layer level. These findings led us to the diagnosis of isolated CILRA occlusion and PAMM associated with recent COVID-19. CILRA occlusion and PAMM could be associated with the inflammatory and procoagulant condition caused by the SARS-CoV-2 infection.
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    PublicationOpen Access
    Protective effect of pomegranate juice on retinal oxidative stress in streptozotocin-induced diabetic rats.
    (2017-11-18) Tugcu, BETÜL; NACAROGLU, SA; GEDIKBASI, A; UHRI, M; ACAR, N; ÖZDEMIR, HÜSEYİN; TUĞCU, BETÜL; ÖZDEMİR, MEHMET HAKAN
    Aim: To investigate the effect of pomegranate juice (PJ) intake on overall oxidation status in retinas of diabetic rats. Methods: Twenty-seven rats were divided into four groups as control (CO), diabetic (DM), control treated with PJ (CO-PJ), and diabetic treated with PJ (DM-PJ).The retina tissues were used to determine 8-hydroxy-2'-deoxyguanosine (8OHdG), malondialdehyde (MDA), reduced glutathione (GSH) levels, and the enzyme activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Results: The levels of 8OHdG and MDA were significantly increased in the retina of DM group compared to CO group (P=0.001, P<0.001 respectively). Both 8OHdG and MDA levels were decreased in PJ-DM group compared to DM group (P=0.004, P<0.001 respectively). The activities of antioxidant enzymes GSH, SOD, and GDH-Px were significantly decreased in the retina of DM group compared to CO group (P≤0.01). GSH and GSH-Px activities were higher in PJ-DM group compared with DM group (P=0.010, P=0.042, respectively) but SOD activity was not statistically different (P=0.938). Conclusion: PJ intake is found to be effective in decreasing oxidative end products, and in increasing the activities of antioxidant enzymes in diabetic retinas of rats, which suggests it may be effective against oxidative stress in diabetic retinas.
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    PublicationOpen Access
    Coronavirus (COVID-19) and its Relationship with Ocular Surface
    (2021-02-01T00:00:00Z) EKİNCİ, CANSU; ÖZDEMİR, MEHMET HAKAN; EKİNCİ, CANSU; ÖZDEMİR, MEHMET HAKAN
    An outbreak in China-s Wuhan city in December 2019, characterized by unidentified pneumonia, leading to severe acute respiratory distress syndrome has begun. The cause of the outbreak has been detected as Severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2), which is a new coronavirus and due to its rapid spread in a short time, it has been announced as a pandemic in terms of public health by the World Health Organization. The virus is transmitted mainly by direct contact with the secretions of patients and inhalation of virus-containing micro-droplets. The transmission of the virus via the ocular route is a controversial issue and there arc limited number of studies in the literature. Follicular conjunctivitis may he one of the ocular manifestations of the disease and even if there is no concomitant conjunctivitis, it is very important for the ophthalmologists and healthcare professionals to take preventive measures. In this review, the relationship of SARS-CoV-2 with ocular surface findings was evaluated in the light of the literature.
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    PublicationOpen Access
    Imaging Methods in the Diagnosis of Optic Disc Drusen.
    (2016-10-01) Tuğcu, BETÜL; Özdemir, HÜSEYİN; TUĞCU, BETÜL; ÖZDEMİR, MEHMET HAKAN
    Optic disc drusen (ODD) are benign congenital anomalies of the optic nerve characterized by calcified hyaline bodies. While superficial drusen can be diagnosed easily during fundus examination, detecting buried drusen requires the use of additional imaging methods such as B-scan ultrasonography (USG), fundus fluorescein angiography (FFA), computed tomography (CT) and fundus autofluorescence (FAF). ODD can be detected by USG with the presentation of highly reflective round structures. ODD appear as hyperautofluorescent areas on FAF and bright spots on CT scans. FFA can be helpful in differentiating ODD from true optic disc edema. Optic disc edema shows early hyperfluorescence due to diffuse leakage whereas ODD presents as well-defined hyperfluorescence in the late phase. In recent years, it has been reported that optical coherence tomography (OCT) examination has allowed more detailed evaluation of ODD and yielded useful findings for the differentiation of optic disc edema from ODD. In this review, the role of OCT in the diagnosis of ODD is discussed.
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    PublicationOpen Access
    Insomnia Might Influence the Thickness of Choroid, Retinal Nerve Fiber and Inner Plexiform Layer.
    (2020-03-19T00:00:00Z) Sahbaz, C; Elbay, AHMET; Ozcelik, M; Ozdemir, H; ELBAY, AHMET; ÖZDEMİR, MEHMET HAKAN
    Sleep may play a fundamental role in retinal regulation and the degree of retinal variables. However, no clinical study has investigated optical coherence tomography (OCT) parameters in patients with primary insomnia. All participants were evaluated with the insomnia severity index (ISI) and the Pittsburgh sleep quality index (PSQI). The retinal nerve fiber layer (RNFL), ganglion cell layer (GC), inner plexiform layer (IPL), macula and choroidal (CH) thickness were compared between 52 drug-naïve patients with primary insomnia and 45 age-gender-BMI-smoke status matched healthy controls (HC). The patients with primary insomnia differed from the HC regarding RNFL-Global (p = 0.024) and RNFL-Nasal inferior (p = 0.010); IPL-Temporal (p < 0.001), IPL-Nasal (p < 0.001); CH-Global (p < 0.001), CH-Temporal (p = 0.004), CH-Nasal (p < 0.001), and CH-Fovea (p = 0.019). ISI correlated with RNFL-Global and RNFL-Nasal inferior. The regression analysis revealed that ISI was the significant predictor for the thickness of RNFL- Nasal inferior (p = 0.020), RNFL-Global (p = 0.031), and CH-Nasal (p = 0.035) in patients with primary insomnia. Sleep disorders are seen commonly in patients with psychiatric, including ocular diseases. Adjusting the effect of insomnia can help to clarify the consistency in findings of OCT.
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    PublicationOpen Access
    Angioid streaks in a case of Camurati-Engelmann disease.
    (2017-07-01) ÖZDEMIR, HÜSEYİN; Tugcu, BETÜL; SEZER, TAHA; ELBAY, AHMET; TUĞCU, BETÜL; SEZER, TAHA; ELBAY, AHMET; ÖZDEMİR, MEHMET HAKAN