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Dive into the research topics where Dilara Pirhan is active.

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Featured researches published by Dilara Pirhan.


Retina-the Journal of Retinal and Vitreous Diseases | 2014

Choroidal thickness changes after a single administration of coffee in healthy subjects.

Asli Vural; Necip Kara; Nihat Sayin; Dilara Pirhan; Hatice Bilge Araz Ersan

Purpose: To investigate the changes in the subfoveal choroidal thickness measured by enhanced depth imaging optical coherence tomography after a single administration of a cup of coffee in healthy subjects. Methods: In this prospective study, 62 healthy subjects (study group) who received a cup of 100 mL Turkish coffee (57 mg caffeine/100 mL) and 54 healthy subjects (control group) who received the same amount of water were enrolled. In the study group, the participants underwent enhanced depth imaging optical coherence tomography scanning at baseline, and at 5 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, and 6 hours after coffee drinking. The participants of the control group simultaneously underwent enhanced depth imaging optical coherence tomography scanning. Subfoveal choroidal thickness measurements were performed on both groups at another time. Results: Baseline choroidal thickness was 328 ± 79 &mgr;m in the study group and 311 ± 79 &mgr;m in the control group (P = 0.381). In the study group, choroidal thickness was significantly lower at 5 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours after coffee drinking when compared with the baseline measurement (P < 0.001, for all); however, there were no significant differences between the measurements at 6 hours and 24 hours after coffee drinking and the baseline measurement (P = 0.113 and P = 0.342, respectively). In the control group, no significant difference was found between each choroidal thickness measurement (P > 0.05, for all). Conclusion: The findings of this study revealed that drinking of a cup of coffee causes a significant decrease in choroidal thickness for at least 4 hours after coffee drinking.


Cytotherapy | 2015

Neuroprotective effects of intravitreally transplanted adipose tissue and bone marrow–derived mesenchymal stem cells in an experimental ocular hypertension model

Esra Emre; Nurşen Yüksel; Gokhan Duruksu; Dilara Pirhan; Cansu Subaşı; Gülay Erman; Erdal Karaoz

BACKGROUND AIMS The purpose of this study was to investigate the neuroprotective effects of bone marrow bone marrow-derived and adipose tissue-derived mesenchymal stromal cells (MSCs) that were intravitreally transplanted in an experimental ocular hypertension (OHT) model. METHODS An OHT rat model was generated by means of intracameral injection of hyaluronic acid into the anterior chamber. MSCs labeled with green fluorescence protein were transplanted intravitreally 1 week after OHT induction. At the end of the second and fourth weeks, retinal ganglion cells were visualized with the use of a flat-mount retina method and were evaluated by means of immunofluorescence staining against green fluorescence protein, vimentin, CD105, and cytokines (interleukin [IL]-1Ra, prostaglandin E2 receptor, IL-6, transforming growth factor-β1, interferon-γ and tumor necrosis factor-α). RESULTS The retinal ganglion cell numbers per area were significantly improved in stem cell-treated OHT groups compared with that in the non-treated OHT group (P < 0.05). The results of immunohistochemical analyses indicated that a limited number of stem cells had integrated into the ganglion cell layer and the inner nuclear layer. The number of cells expressing proinflammatory cytokines (interferon-γ and tumor necrosis factor-α) decreased in the MSC-transferred group compared with that in the OHT group after 4 weeks (P < 0.01). On the other hand, IL-1Ra and prostaglandin E2 receptor expressions were increased in the rat bone marrow-derived MSC group but were more significant in the rat adipose tissue-derived MSC group (P < 0.01). CONCLUSIONS After intravitreal transplantation, MSCs showed a neuroprotective effect in the rat OHT model. Therefore, MSCs promise an alternative therapy approach for functional recovery in the treatment of glaucoma.


Current Eye Research | 2016

Riluzole- and Resveratrol-Induced Delay of Retinal Ganglion Cell Death in an Experimental Model of Glaucoma

Dilara Pirhan; Nurşen Yüksel; Esra Emre; Abdulkadir Cengiz; Demir Kursat Yildiz

Abstract Purpose: To evaluate the effects of the neuroprotective agents riluzole and resveratrol on the survival of retinal ganglion cells (RGCs) when administered alone or in combination. Materials and methods: Experimental glaucoma was induced by injecting hyaluronic acid into the anterior chamber of Wistar albino rats weekly for a six-week period. Intraocular pressure was measured before and immediately after glaucoma induction. The neuroprotective effects of daily intraperitoneal injections of riluzole (8 mg/kg) and resveratrol (10 mg/kg) were evaluated and compared. After the six-week period, dextran tetramethylrhodamine was applied into the optic nerve and the density of surviving RGCs was evaluated by counting the labeled RGCs in whole mount retinas for retrograde labeling of RGCs. Results: The mean numbers of RGCs were significantly preserved in all treatment groups compared to the vehicle-treated glaucoma group (G). The mean number of RGCs in mm2 were 1207 ± 56 in the control group (C), 404 ± 65 in G group, 965 ± 56 in riluzole-treated group in the early phase of glaucoma (E-Ri), 714 ± 25 in riluzole-treated group in the late phase of glaucoma (L-Ri), 735 ± 29 in resveratrol-treated group in the early phase of glaucoma (E-Re), 667 ± 20 in resveratrol-treated group in the late phase of glaucoma (L-Re), and 1071 ± 49 in riluzole and resveratrol combined-treated group in the early phase of glaucoma (E-RiRe group). Conclusions: When used either alone or in combination, both riluzole and resveratrol, two agents with different mechanisms of action in glaucoma, significantly delayed RGC loss in this study’s experimental glaucoma model.


Seminars in Ophthalmology | 2014

Subfoveal Choroidal Thickness in Preeclampsia: Comparison with Normal Pregnant and Nonpregnant Women

Nihat Sayin; Necip Kara; Dilara Pirhan; Asli Vural; Hatice Bilge Araz Ersan; Ali Ismet Tekirdag; Ibrahim Polat; Bekir Gulac; Gokce Yilmaz

ABSTRACT Purpose: To compare the subfoveal choroidal thickness (SFCT) in preeclampsia, normal pregnancy, and non-pregnant women using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: One hundred nineteen volunteers were enrolled in this prospective and comparative study. The participants were divided into three groups: group 1 (33 preeclamptic women), group 2 (46 normal pregnant), and group 3 (40 non-pregnant healthy women). The SFCT was measured by EDI-OCT. The refractive error, intraocular pressure (IOP), axial length (AL), central corneal thickness (CCT), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured. Medical records of pregnant women, including gestational age, maternal weight gain, weight, and proteinuria, were noted. Results: Mean SFCT of groups 1, 2, and 3 were 333.8 ± 55.3 μm (range 235-440 μm), 368.6 ± 67.6 μm (range 223-517 μm), and 334.8 ± 59.9 μm (range 197-432 μm), respectively. The mean SFCT was thicker in group 2 than that in groups 1 and 3 (p = 0.045 and p = 0.038, respectively), whereas no significant difference was seen between groups 1 and 3 (p = 1.0). In group 1, SFCT showed a negative correlation with the CCT (p = 0.009, r = -0.493). In group 2, SFCT showed a positive correlation with OPP (p = 0.030, r = 0.321) and a negative correlation with gestational age and fetal weight (p = 0.008, r = -0.387 and p = 0.011, r = -0.373, respectively). Conclusion: Our results suggested that SFCT was significantly thicker in normal pregnant women than non-pregnant women. However, SFCT values of preeclamptic women were similar to those of non-pregnant women.


Current Eye Research | 2014

Evaluation of Subfoveal Choroidal Thickness in Pregnant Women Using Enhanced Depth Imaging Optical Coherence Tomography

Necip Kara; Nihat Sayin; Dilara Pirhan; Asli Vural; Hatice Bilge Araz-Ersan; Ali Ismet Tekirdag; Gonca Yetkin Yildirim; Bekir Gulac; Gokce Yilmaz

Abstract Purpose: To evaluate the subfoveal choroidal thickness (SFCT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in pregnant women. Methods: In this prospective and cross-sectional study, 100 pregnant women and 100 age-matched nonpregnant women were enrolled. The SFCT was measured by EDI-OCT. The refractive error, intraocular pressure (IOP), axial length (AL), central corneal thickness (CCT), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured. Pregnancy-related factors including gestational age, maternal weight gain, and fetal weight were noted. Results: Mean SFCT was 371.1 ± 61.8 µm in the study group and 337.2 ± 62.4 µm in the control group (p < 0.001). No significant correlation was found between SFCT and spherical refraction, IOP, AL, CCT, OPP, gestational age, maternal weight gain, or fetal weight. Conclusion: Our results suggest that subfoveal choroidal thickness increases in pregnant women compared with age-matched nonpregnant women.


Journal of Glaucoma | 2010

Systemic high-sensitivity C-reactive protein level in pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

Nurşen Yüksel; Dilara Pirhan; Özgül Altntaş; Yusuf Çağlar

PurposeTo evaluate the systemic high sensitivity C-reactive protein (hsCRP) levels in patients with pseudoexfoliation syndrome (XFS) and pseudoexfoliation glaucoma (XFG). Materials and MethodsWe prospectively examined 31 patients with XFS, 26 with XFG, and 25 controls. To the study patients with the exclusion of serious hypertension that do not have any cardiovascular and cerebrovascular disease and that diagnosed as XFS and XFG have been included. Each patient passed through a detailed blood sampling including hsCRP, biochemistry, and lipid profile. Plasma C-reactive protein (CRP) levels were measured with nephelometric method by using Beckman IMMAGE hsCRP reagent. ResultsEach group had similar demographic parameters including age, sex, body mass index, heart rate, and blood pressure. When we compared with controls, there was no statistically significant difference in the hsCRP and biochemistry results between the 3 groups. When all patients with pseudoexfoliation (PEX) compared with controls there was no difference. ConclusionsOur findings indicated no difference in the hsCRP level between XFS, XFG, and controls. This study suggests that CRP is not a predictive marker of inflammation and peripheral endothelial dysfunction in XFS, which is accepted as a systemic disorder.


Current Eye Research | 2016

Evaluation of Corneal Microstructure in Pseudoexfoliation Syndrome and Glaucoma: In Vivo Scanning Laser Confocal Microscopic Study

Nurşen Yüksel; Esra Emre; Dilara Pirhan

Abstract Purpose: To quantitatively evaluate corneas of patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) using in vivo scanning laser confocal microscopy (IVCM). Materials and Methods: The study population comprised 30 patients with PXS, 30 patients with PXG, and 30 normal control subjects. IVCM of the cornea was performed on all participants using the Rostock Cornea Module of the Heidelberg Retinal Tomograph (HRT). Mean outcome measures included density of basal epithelial cells, endothelial cells, and anterior and posterior keratocytes; and tortuosity and density of subbasal plexus nerves. Results: Mean densities of basal epithelial cells, endothelial cells, anterior and posterior keratocytes, and subbasal nerves differed significantly among the three groups. Subbasal nerve densities were significantly diminished in PXS and PXG patients (12.36 ± 2.89 and 6.8 ± 3.42 mm/mm2, respectively) compared with that of control subjects (16.13 ± 3.42 mm/mm2) (p < 0.05). Mean densities of anterior and posterior stromal keratocytes were significantly lower in PXS and PXG patients compared with control subjects (p < 0.05). Endothelial cell densities were 3073.63 ± 654.49, 2592.60 ± 276.36, and 2110.20 ± 620.53 cells/mm2 for control, PXS, and PXG groups, respectively (p < 0.05). The percentages of endothelial cell polymegathism and pleomorphism were higher in PXS and PXG patients compared with control subjects. Endothelial cell polymegathism and pleomorphism were more frequently associated with PXG. Conclusions: Results of this study demonstrate the existence of alterations in the (i) density of cells in the various layers of the cornea, (ii) cellular configuration of corneal endothelial cells, and (iii) density/diameter of the subbasal nerve plexus in patients with PXS, and that such alterations are common in patients with PXG. It would be beneficial to employ IVCM to assess the severity of pseudoexfoliation keratopathy (PXK).


Seminars in Ophthalmology | 2014

Evaluation of Subfoveal Choroidal Thickness in Children with Type 1 Diabetes Mellitus: An EDI-OCT Study

Nihat Sayin; Necip Kara; Dilara Pirhan; Asli Vural; Hatice Bilge Araz Ersan; Hasan Onal; Simge Cınar

Abstract Purpose: To evaluate the subfoveal choroidal thickness (SFCT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in children with type 1 diabetes without diabetic retinopathy. Methods: In this prospective and comparative study, 41 diabetic children without diabetic retinopathy and 42 age-matched healthy subjects were enrolled. The SFCT was measured by EDI-OCT. Correlations between SFCT and diabetic parameters such as fasting glucose level, HbA1c, age, or duration of diabetes were also evaluated. Results: The mean SFCT value was 375.3 ± 66.5 μm in the eyes with diabetes and 356.4 ± 52.0 μm in the control group. The SFCT was not correlated with fasting glucose level, HbA1c, age, or duration of diabetes. Conclusion: This study showed that SFCT of diabetic children are similar to those of healthy controls. In addition, SFCT are not affected by fasting glucose level, HbA1c, age, or duration of diabetes.


Eye & Contact Lens-science and Clinical Practice | 2016

Evaluation of Effect of Topical Tacrolimus Treatment on Herpetic Stromal Keratitis in a Rat Model.

Erdem Eriş; Nurşen Yüksel; Dilara Pirhan; Aynur Karadenizli; Mehmet Şehmuz Aslan; Gulcin Gacar; Gülay Erman; Cansu Subaş; Hüseyin Uzuner; Demir Kürşat Yldz; Erdal Karaoz

Objectives: To investigate the effectiveness of topical tacrolimus treatment on herpetic stromal keratitis (HSK) in a rat model. Methods: The development of HSK was monitored for 14 days after the inoculation of rats with herpes simplex type 1 virus. Rats that developed HSK were divided into four groups as follows: (1) topical antiviral treatment (control), (2) topical antiviral and 1% prednisolone acetate, (3) topical antiviral and 0.03% tacrolimus ointment, and (4) topical antiviral plus 0.1% tacrolimus ointment. After 14 days of treatment, the severity levels of HSK were scored and compared with the levels before the treatment. The expression of CD3, CD4, and CD8 was evaluated by flow cytometry. The development of the disease was evaluated clinically and histologically. Results: Significant improvement in vascularization was observed in the groups with the drug treatment in addition to the antiviral agent (P<0.05), but there was no obvious difference within groups 2, 3, and 4 in the vascularization severity. The regression of corneal edema was 8.05%±6% in group 1, 25.17%±14.55% in group 2 (P=0.01), 36.40%±21.69% in group 3 (P=0.03), and 46.39%±14.96% in group 4 (P=0.00). A significant decrease in the number of inflammatory cells in the groups with the drug treatment was evaluated by immunohistochemical staining and confirmed by flow cytometry analysis. Conclusions: Topical tacrolimus treatment caused a significant decrease in corneal vascularization accompanied by a lower number of inflammatory cells in the experimental HSK corneal edema model. Therefore, topical tacrolimus has the potential to be used in the treatment of HSK.


Current Eye Research | 2016

The Effect of Everolimus on Scar Formation in Glaucoma Filtering Surgery in a Rabbit Model

Ruken Çinik; Nurşen Yüksel; Dilara Pirhan; Mehmet Şehmuz Aslan; Cansu Subaşı; Erdal Karaoz

ABSTRACT Purpose: To investigate the efficiency of everolimus on the prevention of postoperative scar in a rabbit model of glaucoma filtering surgery in comparison with mitomycin-C (MMC).Materials and Methods: Thirty New Zealand albino rabbits were randomly assigned into 3 groups, each including ten rabbits: an everolimus group (Group 1), a MMC group (Group 2), and a sham group (Group 3). A limbal-based trabeculectomy was performed on the right eyes of all the rabbits. For 28 days following surgery, the eyes were evaluated in terms of intraocular pressure (IOP), morphological and biomicroscopic changes, and complications in the bleb. On the 28th day, four eyes randomized from each group were enucleated and histologically and immunohistochemically analyzed. Transforming growth factor-β1 (TGF-β1), metalloproteinase (MMP-2, MMP-9), and proliferative cell nuclear antigen (PCNA) expressions in each group were evaluated. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method was used for apoptosis.Results: Bleb survival was statistically significantly longer for a period in Group 1 compared to Group 2. When postoperative IOPs of three groups were measured, it was seen that there is significant IOP reduction in all three groups. However, there were increases in the mean IOP values beginning from the 5th day in Group 2 and from the 3rd day in Group 3 while in Group 1 mean IOP values began to increase beginning from 10th day and the mean IOP values in Group 1 remained at a lower level in comparison to the other groups for 28 days (p < 0.05). The expressions of TGF-β1, MMP-2, MMP-9, and PCNA were reduced in Group 1 compared to other groups. TUNEL positive apoptotic cells were significantly increased in Group 1 compared to other groups (p < 0.05).Conclusion: Everolimus appears to suppress the proliferation of fibroblast and thus may provide an effective treatment strategy in glaucoma filtering surgery.

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Necip Kara

University of Gaziantep

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