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Öğe Administration of high dose intravitreal melatonin degenerates retinal cells in guinea pigs(2004) Yılmaz, Turgut; Naziroǧlu, Mustafa; Çelebi, Serdal; Özercan, Hanifi İbrahim; Kükner, A. ŞahapThe purpose of this study was to investigate the influence of intravitreally injected different doses of melatonin on retinal morphology. The right eyes of 35 male albino guinea pigs were used. The animals were classified randomly into five groups in equal numbers. First group was used as control and received intravitreal injection of placebo. Groups 2, 3, 4 and 5 received intravitreally injections of melatonin at 50, 100, 150 and 200 ?g/body weight (BW) each, respectively. The animals were sacrificed 15 days after the injections. The eyes were enucleated and processed for light microscopic evaluation.Intravitreal injection of melatonin at doses ranging from 50 to 150 ?g did not induce morphological changes, although a higher thickness of the inner plexiform layer (IPL) was found in Group 5 compared to other groups (p < 0.05). The mean retinal ganglion cell (RGC) counts were found to be lower in Group 5 compared to other groups (p < 0.05).Our findings indicate that intravitreal injection of melatonin at doses ranging from 50 to 150 ?g/BW does not induce morphological changes. The dose of 200 ?g/BW produced significant damage including retinal ganglion cell loss and formation of retinal edema. © 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Alt oblik miyektomi sonrası internal oftalmopleji gelişen iki olgu(2012) Ulaş, Fatih; Doğan, Ümit; Bucak, Y. Yücel; Çelebi, SerdalAlt oblik kası aşırı fonksiyonu nedeniyle kliniğimize başvuran 3 ve 38 yaşlarındaki iki kadın olguya alt oblik miyektomi ameliyatı uygulandı. İki olguda da ameliyat sonrası birinci gün internal oftalmoplejiye bağlı anizokori gelişti. İki olguda da internal oftalmopleji üç ay içerisinde tedavisiz düzeldi.Öğe Aqueous humour and serum concentration of asymmetric dimethyl arginine in pseudoexfoliation syndrome(Bmj Publishing Group, 2012) Tosun, Mehmet; Erdurmuş, Mesut; Buğdaycı, Güler; Çelebi, Serdal; Alçelik, AytekinObjective Asymmetric dimethyl arginine (ADMA) is the major endogenous inhibitor of nitric oxide synthase. ADMA is related to endothelial dysfunction and is an independent cardiovascular risk factor. This study aimed to evaluate the concentration of ADMA in aqueous humour and serum samples of patients with pseudoexfoliation (PEX) syndrome. Materials and Methods 21 cataract patients with PEX syndrome (PEX group) and 18 cataract patients without PEX syndrome (control group) were enrolled in the study. ADMA was measured in the aqueous humour and serum of the PEX and control groups. ELISA was used to determine the ADMA concentration. Results Mean aqueous humour ADMA concentration in the PEX group was 0.39 +/- 0.07 mu mol/l and in the control group was 0.34 +/- 0.06 mu mol/l. Mean serum ADMA concentration in the PEX group was 0.5660.21 mu mol/l and in the control group was 0.4460.12 mu mol/l. ADMA concentration of aqueous humour in the PEX group was significantly higher than the control group (p=0.026). Similarly, ADMA concentration of serum in the PEX group was significantly higher than the control group (p=0.039). Conclusions The findings of the present study could suggest that ADMA might play a role in the aetiopathogenesis of PEX syndrome. Higher aqueous and serum levels of ADMA might be potential evidence of endothelial dysfunction in PEX syndrome.Öğe Association of dehydroepiandrosterone sulfate, serum lipids, C-reactive protein and body mass index with age-related macular degeneration(Springer, 2013) Ulaş, Fatih; Balbaba, Mehmet; Özmen, Sedat; Çelebi, Serdal; Doğan, ÜmitThe present study was designed to evaluate the associations between exudative age-related macular degeneration (AMD) and the serum concentrations of C-reactive protein (CRP), dehydroepiandrosterone sulfate (DHEAS), and lipids as well as the relationship between exudative AMD and body mass index (BMI). This cross-sectional study included of 141 healthy control subjects (70 males and 71 females with a mean age of 71.01 +/- A 3.84 years) and 142 exudative AMD patients (70 males and 72 females with a mean age of 70.92 +/- A 3.60 years). BMI and the serum concentrations of CRP, DHEAS, and lipids were measured in both groups. The data were statistically analysed using the Mann-Whitney U test, Chi squared test, independent sample t test, Cramer's V, point biserial correlation and logistic regression analysis. BMI values and serum concentrations of CRP, total cholesterol, and low-density lipoprotein (LDL) cholesterol were significantly higher in exudative AMD patients compared with normal controls (p values were 0.001, < 0.001, 0.005 and < 0.001, respectively). The serum concentrations of DHEAS were not significantly different between the controls and the exudative AMD patients for the subgroups of either gender (p values in males and females were 0.785 and 0.159, respectively). A logistic regression analysis revealed that the BMI and serum concentration of CRP moderately contributed to the predictive ability of the model (odds ratios were 1.205 and 1.179, respectively). Elevated total cholesterol concentrations and LDL cholesterol concentrations, BMI values and serum concentrations of CRP were associated with exudative AMD. However, no association between the serum DHEAS concentration and exudative AMD was established.Öğe Can hypothyroidism cause acute central serous chorioretinopathy?(Taylor & Francis Inc, 2019) Ulaş, Fatih; Uyar, Enes; Tekçe, Hikmet; Çelebi, SerdalPurpose: To evaluate selected systemic findings, especially thyroid functions, in acute central serous chorioretinopathy (CSC) patients. Materials and Methods: In all, 71 consecutive acute CSC patients who fulfilled the inclusion criteria and 70 age-matched healthy control subjects were included in the study. Systemic findings, including serum levels of thyroid hormones, thyroid stimulating hormone (TSH), mean arterial pressure (MAP), pulse rate, serum lipid levels and optical coherence tomography findings, were compared between the groups. Independent samples t-test was used for statistical analysis. Results: The mean ages of the CSC and control groups were 41.06 +/- 6.49 and 40.06 +/- 7.08 years old, respectively. Retinal thickness, choroidal thickness, TSH levels, pulse rate and MAP were significantly different between CSC patients and healthy control subjects (range of p values: <0.001-0.042). In the logistic regression analysis, MAP, serum triglyceride concentration and central choroidal thickness were positively associated with CSC (range of p values: <0.001-0.035). Conclusion: Acute CSC patients had significantly higher pulse rates and MAP and significantly thicker choroidal thickness than were found in healthy subjects. TSH levels were also significantly higher in CSC patients than in controls. Hence, hypothyroidism might be associated with CSC.Öğe Choroidal thickness changes during the menstrual cycle(Informa Healthcare, 2013) Ulaş, Fatih; Doğan, Ümit; Duran, Bülent; Keleş, Asena; Ağca, Sümeyra; Çelebi, SerdalPurpose: To evaluate the effects of the menstrual cycle on the choroidal thickness of healthy women of reproductive age using spectral-domain optical coherence tomography. Materials and methods: A total of 23 right eyes of 23 women with regular natural menstrual cycles of 28-30 d and ages 22-30 years were included in this prospective study. The choroidal thicknesses of the women were measured using high-resolution spectral-domain optical coherence tomography line scans with the activated enhanced depth imaging mode in the early follicular, ovulatory and mid-luteal phases of the menstrual cycle (3rd, 14th and 21st days) using a follow-up scanning protocol of the Spectralis optical coherence tomograph by setting the early follicular phase scan as the reference image. Choroidal thickness measurements were taken at the fovea and at two points that were 1500 mm nasal and temporal to the fovea. The mean arterial pressure, spherical equivalent, intraocular pressure, central corneal thickness and retinal and retinal nerve fiber layer thicknesses were also measured. All measurements were taken within the same menstrual cycle. Results: The mean +/- standard deviation (standard error of the mean) of subfoveal choroidal thicknesses in the early follicular, ovulatory and mid-luteal phases were 383.87 +/- 84.38 (17.59), 373.74 +/- 82.40 (17.18) and 359.09 +/- 79.65 (16.61) mm, respectively. The relative reductions in choroidal thickness between early follicular and ovulatory phases and early follicular and mid-luteal phases were 2.64% and 6.47%, respectively. The subfoveal choroidal thickness was decreased significantly in the mid-luteal phase when compared with both the early follicular (p<0.001) and ovulatory phases (p = 0.003). However, the measures of subfoveal choroidal thickness in the early follicular phase were non-conclusively greater (p = 0.071) than in the ovulatory phase. Additionally, the mean arterial pressure, spherical equivalent, intraocular pressure, central corneal thickness and retinal and retinal nerve fiber layer thicknesses did not significantly differ during the menstrual cycle (p>0.05 for all). Conclusions: The choroidal thickness decreased significantly in the mid-luteal phase of the menstrual cycle in young, healthy women. These findings emphasize the importance of the menstrual phase in the interpretation of choroidal thickness measurements in women of reproductive age.Öğe A comparative study of bimatoprost and travoprost: Effect on intraocular pressure and ocular circulation in newly diagnosed glaucoma patients(Karger, 2008) Alagöz, Gürsoy; Gürel, Kamil; Bayer, Atilla; Serin, Didem; Çelebi, Serdal; Kükner, ŞahapBackground: This study compares intraocular pressure (IOP)-lowering efficacy and retrobulbar hemodynamic effects of bimatoprost and travoprost in patients with newly diagnosed open-angle glaucoma. Methods: Patients were randomly assigned to one of two treatment groups ( bimatoprost group, n = 36; travoprost group, n = 46). IOP levels were measured with Goldmann applanation tonometer. Peak systolic velocity, end-diastolic velocity and resistivity index were obtained for each vessel by color Doppler imaging. Results: Both bimatoprost and travoprost significantly lowered IOP on days 30, 90 and 180 (p < 0.001). There was no significance between the 2 drugs on all follow-up visits. End-diastolic velocity of central retinal artery on day 180 was significantly higher than the value obtained at baseline in both groups. Conclusions: Patients were likely to achieve and maintain low target IOP with both drugs. Both drugs also resulted in improvement in the central retinal artery blood flow. Copyright (c) 2008 S. Karger AG, Basel.Öğe A comparison of short-term effects of intravitreal triamcinolone acetonide and bevacizumab on retinal vascular caliber in patients with diabetic macular edema(2013) Ulaş, Fatih; Do?an, Ümit; Çelik, Fatih; Şahin, Saygin; Çelebi, SerdalPurpose: To compare the retinal vascular caliber changes in diabetic macular edema patients receiving intravitreal triamcinolone acetonide and bevacizumab. Materials and Methods: Retinal vascular caliber of 42 patients with diabetic macular edema aged between 41-78 were measured before, 1 week and 4 weeks after the intravitreal injection. 21 (50.0%) patients received 2 mg/0.05 ml intravitreal triamcinolone acetonide and 21 (50.0%) patients received 1.25 mg/0.05 ml intravitreal bevacizumab. Retinal vascular caliber assessment was performed manually on retinal nerve fiber layer imaging mode scan by using semi-automated program of Spectralis optical coherence tomography. Statistical analyses of differences between retinal vascular caliber were determined using repeated measures of analysis of variance and Bonferroni adjustment. Results: Mean retinal arteriolar diameter of healthy control group, triamcinolone group, and bevacizumab group before the injection was 88.55±11.29, 87.19±10.00 and 91.67±16.69 ?m, respectively. Mean retinal venular diameter of healthy control group, triamcinolone group, and bevacizumab group before the injection was 127.00±16.91, 130.38±24.01 and 132.52±18.74 ?m, respectively. In triamcinolone group, there was statistically significant decline in retinal arteriolar and venular diameter during the study period (p values were 0.047 and <0.001, respectively). In bevacizumab group, retinal venular diameter was significantly decreased (p<0.001) but there was no significant change in retinal arteriolar diameter during the study period (p=0.209). Conclusions: In short-term, intravitreal triamcinolone acetonide led to more significant changes than intravitreal bevacizumab in retinal vascular caliber.Öğe Comparison of the effect of intravitreal bevacizumab and intravitreal fasudil on retinal VEGF, TNF alpha, and caspase 3 levels in an experimental diabetes model(Ijo Press, 2014) Çelik, Fatih; Ulaş, Fatih; Özünal, Zeynep Güneş; Fırat, Tülin; Çelebi, Serdal; Doğan, ÜmitAIM: To evaluate the influence of an intravitreal injection of bevacizumab and fasudil on the retinal vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNF alpha), and caspase 3 levels in a diabetic rabbit model. METHODS: The study included 6 healthy rabbits (Group 1), 6 rabbits with experimentally induced diabetes mellitus (DM) (Group 2), 7 rabbits with experimentally induced DM to which intravitreal bevacizumab was administered (Group 3), and 7 rabbits with experimentally induced DM to which intravitreal fasudil was administered (Group 4). An intravitreal injection of 1.25mg/50 mu L bevacizumab in the right eye of rabbits in Group 3 and an intravitreal injection of 0.0064mg/50 mu L fasudil in the right eye of rabbits in Group 4 were administered on day 21 after the induction of DM. The studied eyes of the rabbits were enucleated three days after the intravitreal injection. The TNF alpha, VEGF, and caspase 3 levels were determined using the ELISA method. RESULTS: There was a statistically significant difference in the VEGF and caspase 3 levels between groups (P=0.005 and P=0.013, respectively), but the TNF alpha level did not differ significantly between groups (P=0.792). It was found that VEGF levels were significantly lower in Group 1 and Group 3 than in Group 2 using the Mann-Whitney Utest with the Bonferroni correction (P=0.004 for both comparison). There was no statistically significant difference between other groups with regard to VEGF levels (the P value ranged between 0.015 and 0.886). Although the P values of the caspase 3 levels were 0.015 for Group 1 and Group 4, 0.038 for Group 2 and Group 3, and 0.018 for Group 3 and Group 4, these P values remained above the threshold Pvalue of 0.0083, which was the statistically significant level for post hoc tests. CONCLUSION: An intravitreal injection of bevacizumab decreased both the VEGF level, which plays a role in angiogenesis, and the caspase 3 level, which plays a role in apoptosis. Although not as effective as bevacizumab, fasudil had a beneficial effect on the VEGF levels but significantly increased the caspase 3 levels.Öğe Dejeneratif miyop hastada şeffaf lens ekstraksiyonu sonrası gelişen anizokori(2013) Ulaş, Fatih; Çelik, Fatih; Doğan, Ümit; Çelebi, SerdalDejeneratif miyopi 20-50 yaş arasındaki kişilerde görme azalmasının önemli nedenlerindendir. Patolojik mekanizma tam olarak bilinmese de genetik ve çevresel faktörlerin birlikte rol oynadığı düşünülmektedir. Dejeneratif miyopide sklera, koro- id, Bruch membranı, pigment epiteli ve retinada ikincil dejeneratif değişiklikler gelişmektedir. Dejeneratif miyopide şeffaf lens ekstraksiyonu uygulanan tedavi yöntemlerinden biridir. Olgumuz 26 yaşında olup, her iki gözde dejeneratif miyopisi vardı ve her iki gözüne şeffaf lens ekstraksiyonu ve katlanabilir IOL implantasyonu yapıldı. Sağ göze yapılan ilk ameliyat sonrası anizokori geliştiği gözlendi. Sol göze şeffaf lens ekstraksiyonu yapıldıktan sonra anizokorinin düzeldiği ve her iki pupillanın izokorik olduğu görüldü. Meydana gelen anizokorinin kristalin lensin iris üzerindeki mekanik etkisinin kalkma- sına bağlı olarak geliştiğini düşünmekteyiz.Öğe Disosiye horizontal deviasyon: 13 olguda klinik bulgular ve cerrahi tedavi sonuçları(2003) Çelebi, Serdal; Aydemir, Orhan; Yılmaz, TurgutAmaç: Disosiye Horizontal Deviasyon (DHD) abduktor komponentin belirgin olduğu disosiye bir şaşılık türüdür. DHD 'nin iki karekteristik özelliği, asimetrik horizontal kayma ve değişken kayma açısı mevcudiyetidir. Bu çalışmada DHD1H olguların klinik özellikleri ve ameliyat sonrası sonuçları değerlendirilmiştir. Gereç ve Yöntem: Çalışmaya alman 13 hastanın 4'ü erkek, 9'u kadındı. Hastaların ortalama yaşı 9.6±5.6 (4-21) idi. DHD tanısı alternan örtme-açma ve prizma örtme testi ile konuldu. Tüm hastalara cerrahi tedavi uygulandı. Ekzodeviasyonu belirgin olan olgulara 8 mm lateral rektus kası geriletmesi, ezodeviasyonu belirgin olan olgulara ise 6 mm lateral rektus kası geriletmesi yapıldı. Beraberinde disosiye vertikal deviasyon (DVD) veya alt oblik kas hiperfonksiyonu mevcut olan olgularda bu patolojiler de aynı cerrahi seansta düzeltildi. Bulgular: DHD; 10 olguda (%77) ekzodeviasyon, 3 olguda (%23) ezodeviasyon şeklindeydi. Yedi olguda (%54) tek gözde, 6 olguda (%46) her iki gözde tutulum mevcuttu. Belirgin DHD 'si mevcut gözlerde en yüksek kayma açısı ortalama değer olarak 36.5±2.4 (25-55) prizm diyoptri (PD) olarak ölçüldü. Ameliyat öncesi iki göz arası horizontal kayma açısı farkı ortalama değer olarak 30.0±10.2 (15-55) PD iken, ameliyat sonrası ise bu fark tüm hastalarımızda 10 PD altında saptandı. Sonuç: DHD 'nin klinik özellikleri oldukça karışıktır. İki göz arasındaki kayma açısı sabit olmayıp, her iki gözde değişik zamanlarda farklı kaymalar gözlenir. DHD'nin ekzodeviasyon ile birlikte olduğu gözlerde aynı taraf lateral rektus kasına 8 mm geriletme, ezodeviasyon ile birlikte olduğu gözlerde aynı taraf lateral rektus kasma 6 mm geriletme yapılması cerrahi tedavi seçimi olabilir.Öğe Diyabetik maküler ödemi olan hastalarda intravitreal triamsinolon asetonid ve bevacizumabın retinal damar çapı üzerine kısa dönem etkilerinin karşılaştırılması(2013) Ulaş, Fatih; Doğan, Ümit; Çelik, Fatih; Şahin, Saygın; Çelebi, SerdalAmaç: Diyabetik maküla ödemi nedeniyle intravitreal triamsinolon asetonid ve bevacizumab uygulanan hastalarda retina damar çapı değişikliklerinin karşılaştırılması. Gereç ve Yöntem: Yaşları 41-78 arası değişen 42 diyabetik maküla ödemi olan hastanın intravitreal enjeksiyondan önce, enjek- siyondan bir hafta ve dört hafta sonra retina damar çapı ölçümleri gerçekleştirildi. Hastaların 21’ine (%50.0) 2 mg/0.05 ml intra- vitreal triamsinolon asetonid ve 21’ine (%50.0) 1.25mg/0.05 ml intravitreal bevacizumab uygulandı. Retinal damar çapı ölçümleri, Spectralis optik koherens tomografi cihazındaki retina sinir lifi ölçüm modu görüntüsü kullanılarak cihazda yüklü olan yarı oto- matik program yardımı ile manuel olarak yapıldı. Retina damar çapı değişiklikleri arasındaki farkın istatistiksel analizi ilişkili örneklem tek yönlü varyans analizi ve Bonferroni düzeltmesi ile değerlendirildi. Bulgular: Sağlıklı kontrol grubu ile triamsinolon ve bevacizumab gruplarının enjeksiyon öncesi ortalama retinal arteriyol çapları sırasıyla 88.55±11.29, 87.19±10.00 ve 91.67±16.69 ?m idi. Sağlıklı kontrol grubu ile triamsinolon ve bevacizumab gruplarının enjeksiyon öncesi ortalama retinal venül çapları sırasıyla 127.00±16.91, 130.38±24.01 ve 132.52±18.74 ?m idi. Triamsinolon gru- bunda çalışma süresince istatistiksel olarak anlamlı düzeyde retina arteriyol ve venüllerinde daralma gözlendi (p değerleri sıra- sıyla 0.047 ve <0.001). Çalışma süresince bevacizumab grubunda, retina venüllerinde istatistiksel olarak anlamlı daralma olurken (p<0.001), retina arteriyollerinde istatistiksel olarak anlamlı değişiklik saptanmadı (p=0.209). Sonuç: Kısa dönem değerlendirmelerinde, retina damar çaplarında intravitreal olarak uygulanan triamsinolon asetonid, bevaci- zumabdan daha belirgin değişikliklere neden olmaktadır.Öğe Diyabetik olmayan kronik böbrek yetmezliği hastalarında hemodiyalizin gözdeki etkileri(Turkiye Klinikleri, 2014) Ulaş, Fatih; Doğan, Ümit; Keleş, Asena; Ertilav, Muhittin; Tekçe, Hikmet; Çelebi, Serdal; Taslamacıoğlu, TubaObjective: To evaluate effects of hemodialysis on best-corrected visual acuity (BCVA), spherical equivalent, central corneal thickness (CCT), intraocular pressure (IOP), macular volume, and retinal nerve fiber layer (RNFL) thickness in non-diabetic chronic renal failure (CRF) patients. Material and Methods: Twenty-four eyes of 20 male and 4 female CRF patients aged between 46-78 years (mean 61.13±10.31 years) were included in this cross-sectional study. BCVA, spherical equivalent, CCT, IOP, macular volume and RNFLthickness measurements of the patients were recorded before and after hemodialysis. Statistical analysis of the data was carried out using paired sample t-test, Wilcoxon signed rank test and Pearson correlation analysis. Results: Hemodialysis significantly decreased plasma osmolality (p<0.001), increased plasma colloid oncotic pressure (p<0.001) and did not alter mean arterial pressure (p=0.139). There was no statistically significant difference in BCVA, spherical equivalent, CCT and all evaluated macular segment volumes (p values were >0.05). IOP decreased significantly after hemodialysis (p=0.007). There was statistically significant increase in all RNFLsegments (p values for global, superotemporal, superonasal, inferotemporal and inferonasal segments were 0.005, 0.002, 0.021, 0.041 and 0.024, respectively) except in nasal and temporal RNFLsegments. There was no significant correlation between all measured parameters (p values were >0.05) except for moderate significant correlation between plasma colloid osmotic pressure difference and CCT difference (r=-0.451, p=0.027), and plasma colloid osmotic pressure difference and IOP difference (r=-0.415, p=0.044). Conclusion: Hemodialysis did not alter BCVA, spheric equivalent, CCT and macular volume, but altered IOP and RNFLthickness significantly in nondiabetic CRF patients. Ophthalmologic examination of CRF patients treated with hemodialysis must be performed at the same time point based on the time of the hemodialysis sessions.Öğe Diyabetik retinopati gelişmemiş diyabetik olgularda retina, retina sinir lifi tabakası ve koroid kalınlığının değerlendirilmesi(2015) Ulaş, Fatih; Doğan, Ümit; Çelik, Fatih; Soydan, Adem; Çelebi, Serdal; Dikbaş, OğuzAmaç: Diyabetik retinopati gelişmemiş diyabetik olguların retina, retina sinir lifi tabakası (RSLT) ve koroid tabakası kalınlığının sağlıklı bireylerle karşılaştırılması.Gereç ve Yöntem: Çalışmaya 37-78 yaş arasında 133 diyabetik retinopati gelişmemiş diyabetik olgu ve 60 sağlıklı birey dahil edildi. Olguların Fourier prensibiyle çalışan optik koherens tomografi cihazı ile artırılmış derinlik görüntülemesi (enhanced depth imaging) modunda horizontal çizgisel taraması yapıldı. Alınan görüntülemelerde fovea merkezinden, fovea merkezine 1500 µm nazalden ve 1500 µm temporalden retina ve koroid kalınlıkları ölçümü yapıldı. Ayrıca cihazda yüklü bulunan RSLT kalınlığı ölçüm modu değerlerinde değişiklik yapılmaksızın RSLT kalınlığı ölçümü yapıldı.Bulgular: Çalışmaya dahil edilen DM grubunun yaş ortalaması 52.75±12.74 kontrol grubunun yaş ortalaması 53.83±5.95 idi. Göz içi basıncı (GİB) değerleri DM grubunda 16.26±2.90 mmHg ve kontrol grubunda 13.18±2.13 mmHg idi (p<0,001). Santral retina kalınlığı DM grubunda 226.24±18.78 µm, kontrol grubunda 216.37±14.79 µm idi (p<0.001). Subfoveal koroid kalınlığı DM grubunda 301.95±76.20 µm, kontrol grubunda 346.62±82.14 µm idi (p=0.001). RSLT kalınlığında ise gruplar arasında istatistiksel olarak anlamlı fark saptanmadı (p=0.494). Spearman testi ile korelasyon değerlendirmesinde diyabet varlığının artmış foveal retina kalınlığı, azalmış subfoveal koroid kalınlığı ve artmış GİB ile birliktelik gösterebileceği belirlendi (rho değer aralığı -0.262 ile 0.543, p<0.001).Sonuç: DM grubu sağlıklı bireylerle karşılaştırıldığında daha kalın retina, daha ince koroid kalınlığı ve daha yüksek GİB değerleri saptanmıştır. Gruplar arasında RSLT kalınlığı bakımından belirgin fark saptanmamıştır. Sonuçlarımız diyabetik retinopati gelişmemiş diyabetik olgularda GİB ve arka segment değerlendirilmesinin dikkatli yapılması gerektiğini göstermektedirÖğe Effect of smoking on choroidal thickness in healthy smokers(Informa Healthcare, 2014) Ulaş, Fatih; Çelik, Fatih; Doğan, Ümit; Çelebi, SerdalPurpose: To evaluate the acute and chronic effects of cigarette smoking on the choroidal thickness of young male smokers with smoking histories exceeding 10 years using spectral domain optical coherence tomography (SD OCT). Materials and methods: The right eyes of 40 never-smoking and 30 smoking healthy subjects were included in this study. We measured the choroidal thicknesses of the never-smoking subjects as a control group. The choroidal thicknesses of the smoking subjects were measured before, 5, 30 and 60 min after smoking. Choroidal thickness measurements were taken at the fovea and at two points that were 1500 mm nasal and temporal to the fovea. Results: No significant difference was found for the retinal thickness, choroidal thicknesses, spherical equivalent, intraocular pressure and central corneal thickness of the smokers and non-smokers (p>0.05 for all). In the measurements that were taken after smoking, a statistically significant increase was found in choroidal thickness that was observed between 0 and 5 min for the central, nasal and temporal segments (p<0.001 for all). Conclusions: Smoking caused acute, significant increase in choroidal thickness that returned to baseline levels after 1 h. The choroidal and retinal thicknesses did not differ significantly between the healthy young smokers and non-smokers.Öğe Effect of fasting on choroidal thickness and Its diurnal variation(Taylor & Francis Inc, 2019) Uyar, Enes; Doğan, Ümit; Ulaş, Fatih; Çelebi, SerdalPurpose: The aim of this study was to assess the effect of Ramadan fasting on choroidal thickness (CT) and its associated diurnal variations using spectral domain optic coherence tomography. Materials and Methods: Ocular measurements were performed on a single eye of 87 healthy individuals. Eyes were evaluated twice a day around 8.00 a.m. and 4.00 p.m. during Ramadan. Evaluations were repeated at the same time of the day, 1 month following Ramadan on the same subjects. Measurements of choroidal and retinal thickness were performed at central, temporal and nasal segments. Results: The comparison of measurements revealed that temporal CT at 8.00 a.m. and foveal, temporal and nasal CTs at 4.00 p.m. were significantly reduced during fasting (p values were 0.005, <0.001, 0.001 and 0.046, respectively). Mean changes of CTs during fasting were 14.76 +/- 16.01, 9.90 +/- 19.57 and 8.10 +/- 16.81 mu m at the fovea, temporal and nasal segments, respectively. However, CTs at non-fasting conditions were measured as 6.13 +/- 12.93, 3.78 +/- 15.23 and 5.05 +/- 13.60 mu m, respectively. In comparison, diurnal variations of foveal and temporal CTs during fasting were significantly higher than the controls (p values were <0.001 and 0.004, respectively). Additionally, retinal thicknesses during fasting were significantly reduced compared to the controls in all segments measured at 4.00 p.m. (p for all values <0.05) Conclusions: The results of the present study revealed that fasting and dehydration caused a reduction of the choroidal and retinal thicknesses. Likewise, they are also responsible for the increased diurnal variation of CTs. Therefore, early hours of the day may be preferred to evaluate retinal and choroidal thicknesses during Ramadan to avoid the effects of dehydration on the measurement results.Öğe Effect of prophylactic intraocular pressure-lowering medication on pain during cataract surgery(Mary Ann Liebert, Inc, 2013) Ulaş, Fatih; Balbaba, Mehmet; Çelebi, SerdalPurpose: This study evaluated the effects of acetazolamide, latanoprost, travoprost, bimatoprost, brimonidine, brinzolamide, and timolol on pain during phacoemulsification cataract surgery. Methods: This prospective randomized comparative study included 323 eyes of 323 patients with no history of intraocular surgery or chronic eye disease who underwent uncomplicated phacoemulsification cataract surgery and foldable intraocular lens implantation under topical anesthesia. Patients were divided into 8 groups according to the preoperative prophylactic intraocular pressure (IOP)-lowering medication. The intraoperative pain was assessed postoperatively using a visual analog pain scale. The Kruskal-Wallis test investigated the differences in the visual analog pain-scale scores of the groups, and the Mann-Whitney U test investigated the pairwise comparison of the groups. Results: The median visual analog pain-scale score of the group that did not receive any IOP-lowering medication was 2.0 +/- 1.89. The brimonidine group exhibited the lowest visual analog pain-scale scores, and the prostanoids, especially the bimatoprost group, demonstrated the highest visual analog pain-scale scores (median +/- standard deviation were 0.0 +/- 1.50 and 2.0 +/- 1.91, respectively). The median visual analog pain-scale scores of the acetazolamide, latanoprost, travoprost, brinzolamide, and timolol groups were 0.0 +/- 1.62, 2.0 +/- 1.67, 2.0 +/- 1.73, 0.0 +/- 1.66, and 1.0 +/- 1.54, respectively. A pairwise comparison using the Mann-Whitney U test with Bonferroni correction revealed significant differences between the groups of acetozolamide and travoprost (p = 0.001), acetozolamide and bimatoprost (p < 0.001), travoprost and brimonidine (p < 0.001), bimatoprost and brimonidine (p < 0.001), and bimatoprost and timolol (p = 0.001). Conclusions: Prophylactic application of the IOP-lowering medication may alter the pain sensation during phacoemulsification cataract surgery.Öğe Effect of quadrant switch on intraocular pressure change in intravitreal aflibercept or ranibizumab injection applications(Springer, 2022) Altıntaş, Melek; Ulaş, Fatih; Çelebi, Serdal; Uyar, EnesObjective To evaluate the effect of injection quadrant switch on the intraocular pressure (IOP) change in intravitreal aflibercept or ranibizumab applications. Methods 123 eyes of 123 patients who received intravitreal injection (IVE) into the superotemporal quadrant at least 10 times for age-related macular degeneration or diabetic macular edema have been recruited. The demographic data, lens status, IOP values (preoperative, postoperative 0th min, and postoperative 30th min), and amount of vitreous reflux (VR) following IVE have been recorded. Next IVE application was performed into the inferotemporal quadrant of the patient, which had never been injected before. Results The mean IOP value at postoperative 0th min was 50.24 +/- 7.66 mmHg after injections into the superotemporal quadrant and was 34.85 +/- 4.96 mmHg after injections into the inferotemporal quadrant. No significant difference was observed between the preoperative and postoperative 30th min-IOP values (p > 0.05), while a significant difference was found between the postoperative 0th min-IOP values among quadrants (p < 0.001). VR was significantly higher in applications into the inferotemporal quadrant than those into the superotemporal quadrant (p < 0.001). Conclusion One of the most principal factors affecting the postoperative short-term IOP increase is the amount of VR, and this amount decreases the IOP following an IVE. The high amount of VR produced in the quadrant where the injection was applied for the first time caused a low-level IOP, while the low amount of VR formed in the quadrant where the repeated injections were applied caused a higher IOP.Öğe Effect of serum parathormone level on retinal thickness and choroidal thickness in chronic renal disease(Gazi Eye Foundation, 2015) Ulaş, Fatih; Doäan, Ümit; Keleş, Asena; Ertilav, Muhittin; Tekçe, Hikmet; Çelebi, SerdalPurpose: To evaluate effects of serum parathormone level on retinal thickness and choroidal thickness in non-diabetic predialysis chronic renal disease (CRD) patients. Materials and Methods: Sixty-five eyes of 45 non-diabetic predialysis CHD patients and 20 healthy subjects were included in this cross-sectional study. Twenty-five CHD patients had high serum PTH levels and 20 CHD patients had PTH levels within normal limits. Spherical equivalent, central corneal thickness (CCT), intraocular pressure (IOP), retinal and choroidal thicknesses of CHD patients and healthy control subjects were measured. Serum creatinine, calcium, phosphor, C-reactive protein (CRP), vitamin D3 and PTH levels were recorded. Statistical analysis of data was carried out using independent samples t test, one-way analysis of variance and Pearson correlation analysis. Results: There was no statistically significant difference in serum calcium, phosphor, vitamin D3 and CRP levels (range of p values: 0.117-0.412) except for serum PTH levels (p<0.001). There was no statistically significant difference in age, spherical equivalent, CCT, and IOP measurements of groups (p values were ranging between 0.067-0.792). There was statistically significant difference in nasal and temporal retinal segment thicknesses between CHD patients and healthy control subjects (p values were 0.044 and 0.024, respectively). Patients with high serum PTH levels had thicker choroid than other 2 groups for all the measured segments, however this difference was not statistically significant (range of p values: 0.438-0.794). Conclusions: Retinal thickness decreased in non-diabetic predialysis CHD patients and high serum PTH levels might affect choroidal thickness in this group of CHD patients.Öğe Effects of a water-loading test on intraocular pressure and corneal hysteresis in young healthy subjects(Lippincott Williams & Wilkins, 2014) Ulaş, Fatih; Balbaba, Mehmet; Çelebi, SerdalPurpose:To evaluate the influence of a water-loading test on corneal compensated intraocular pressure (IOPcc) and corneal hysteresis (CH) in young healthy subjects.Materials and Methods:Forty healthy adult subjects (20 female and 20 male), with a mean age of 27.552.57 years (range, 24 to 35 y), participated in this prospective study. IOPcc and CH were measured for 1 eye from each participant with an Ocular Response Analyser. These measurements were taken before and 10, 20, and 30 minutes after water loading.Results:Thirty-seven right and 3 left eyes of the 40 subjects fulfilled the study's inclusion criteria. A statistically significant increase in IOPcc was observed between 0 and 10 minutes (P=0.002) and a significant decrease between 10 and 30 minutes (P<0.001). We did not observe any statistically significant changes in CH. The Pearson correlation revealed that there was a weak negative correlation between IOPcc and CH measurements taken at the baseline, 10 minutes, and 30 minutes [r values were -0.275 (P=0.086), -0.369 (P=0.019), and -0.246 (P=0.125), respectively].Conclusions:This study revealed changes in IOPcc and CH after a water-loading test, but only the change in the IOPcc measurement was statistically significant. The association of changes in IOP and CH identified in this study suggests that IOP changes might alter corneal biomechanical properties.
