Gülizar Demirok
Ufuk University
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Publication
Featured researches published by Gülizar Demirok.
Seminars in Ophthalmology | 2017
Gülizar Demirok; Yasemin Topalak; Mustafa M. Başaran; Gökçe K. Ataç; Sertaç Öztürk; Ahmet Sengun
ABSTRACT Introduction: The choroid receives about 65–85% of ocular blood flow, which comes from the ophthalmic artery (OA), the first branch of the internal carotid artery (ICA). In the foveal avascular zone, there is no retinal vascular supply; therefore, choroidal blood supply plays a significant role in this subfoveal region. The ocular pulse amplitude (OPA) provides useful information about intraocular blood flow and is an indirect indicator of choroidal perfusion. In this study, we aimed to assess the correlation between the OPA, subfoveal choroidal thickness (CT), and ICA Doppler ultrasound findings in healthy eyes. Methods: In total, 48 eyes of 48 healthy volunteers were included in this study. All eyes underwent detailed ophthalmic evaluation, including slit-lamp biomicroscopy, fundus examination, axial length, OPA measurements, and optical coherence tomography (OCT) with enhanced depth imaging mode. Carotid Doppler ultrasound examination was performed by the radiologist. The correlation between the OPA, subfoveal CT, and ICA Doppler findings [peak systolic velocity (PSV) and end-diastolic velocity (EDV)] were evaluated, considering gender and age. Results: The mean OPA was 3.06 ± 1.34 mmHg. The mean subfoveal CT was 305.85 ± 33.98 µm. The mean PSV and EDV of ICA were 73.25 ± 23.63 cm/s and 26.93 ± 13.42 cm/s, respectively. A moderate positive correlation was found between OPA and subfoveal CT (p = 0.001; rho = 0.481). This relationship was present in both men and women. While a positive correlation was found between the OPA and subfoveal CT in subjects under the age of 50 years, there was no correlation in those over the age of 50 years. Conclusions: A fair correlation was found between the OPA and subfoveal CT in healthy subjects under the age of 50.
Journal of Glaucoma | 2017
Mehmet Yakin; Umit Eksioglu; Gulten Sungur; Banu Satana; Gülizar Demirok; Firdevs Örnek
Purpose: To evaluate short-term to long-term outcomes of Ahmed glaucoma valve (AGV) implantation in the management of uveitic glaucoma (UG) secondary to Behçet disease (BD). Patients and Methods: A retrospective chart review of 47 eyes of 35 patients with UG secondary to BD who underwent AGV implantation was conducted. Success was defined as having an intraocular pressure (IOP) between 6 and 21 mm Hg with (qualified success) or without (complete success) antiglaucomatous medications and without need for further glaucoma surgery. Results: Mean postoperative follow-up was 57.72±26.13 months. Mean preoperative IOP was 35.40±8.33 mm Hg versus 12.28±2.90 mm Hg at the last follow-up visit (P<0.001). Mean number of preoperative topical antiglaucomatous medications was 2.96±0.29 versus 0.68±1.12 at the last follow-up visit (P<0.001). In all eyes, IOP could be maintained between 6 and 21 mm Hg with or without antiglaucomatous medications during follow-up. The cumulative probability of complete success was 46.8% at 6 months, 40.4% at 12 months, and 35.9% at 36 months, and the cumulative probability of eyes without complication was 53.2% at 6 months, 46.5% at 12 months, and 39.6% at 24 months postoperatively based on Kaplan-Meier survival analysis. No persistent or irreparable complications were observed. Conclusions: This study includes one of the largest series of AGV implantation in the management of UG with the longest follow-up reported. AGV implantation can be considered as a primary surgical option in the management of UG secondary to BD with 100% total success rate (with or without medications).
Current Eye Research | 2017
Yeşim Altay; Ozgur Balta; Gülizar Demirok; Ayse Burcu; Oyku Bezen Balta; Firdevs Örnek
ABSTRACT Purpose: To evaluate the agreement of corneal thickness (CT) measurements obtained by the Pentacam Scheimpflug camera, noncontact specular microscopy (SM), and ultrasonographic pachymetry (UP) in diabetic (DM) patients; and whether duration of diabetes and level of Hb A1c affect the agreement.Materials and Methods: The CT was measured in 127 patients with DM, and 137 age and sex-matched healthy controls sequentially by Pentacam, SM, and UP. Also diabetic subjects were subdivided according to duration of diabetes and Hb A1c levels. Pearson correlation analysis, linear regression analysis, and Bland–Altman plots were used for examination of agreement.Results: We found an excellent and statistically significant correlation of CT measurements between Pentacam–SM (R2 = 0.768; R2 = 0.855), Pentacam–UP (R2 = 0.546; R2 = 0.652), and SM–UP (R2 = 0.759; R2 = 0.797) in diabetic and control groups, respectively. We performed further comparisons of the pair of instruments using the Bland–Altman analysis, and the mean difference between pair of methods was much smaller for SM–UP pair (−4.20 ± 9.79 in diabetic, and −4.58 ± 8.08 in control group). The group having Hb A1c level less than 7.5% showed the best agreement between SM–UP pair as in the control group. Whereas Pentacam–UP showed the best agreement in the group having Hb A1c level ≥7.5%. The best agreement was between Pentacam–UP in 0–4 year group, and between Pentacam-SM in 5–9 year and ≥10 year groups.Conclusion: SM–UP pair showed a higher agreement in diabetic patients. According to subgroup analyses, Hb A1c level, rather than the duration of diabetes, may determine the agreement of these pachymetry devices. But the difference in CT measurements between devices can still influence clinical diagnosis and treatment. Therefore, these methods are not completely interchangeable.
Scientifica | 2016
Yeşim Altay; Mehmet Metin Altay; Gülizar Demirok; Ozgur Balta; Hülya Bolu
Purpose. To show whether pregnancy affects the measurements of pupillary diameter and wavefront (WF) aberrations. Methods. This was a case-control study including 34 healthy pregnant women in the third trimester and age-matched 34 nonpregnant women. Only women who had no ocular abnormalities and no refractive error were included. We measured photopic and mesopic pupil diameter and WF aberrations at the third trimester and at the second postpartum month. Measurements of the right eyes were used in this study. The differences between groups were analysed by paired t-test and t-test. Results. Pregnant womens mean photopic pupil size in the third trimester was significantly higher than in postpartum period and in control group (3.74 ± 0.77, 3.45 ± 0.53, and 3.49 ± 0.15 mm, p < 0.05, resp.). Mesopic pupil size in the third trimester was also higher than in postpartum period and in control group (6.77 ± 0.52, 6.42 ± 0.55, and 6.38 ± 0.21 mm, p < 0.05, resp.). RMS-3 and RMS-5 values were higher in pregnancy but these differences were not statistically significant. Conclusion. Pregnancy increased photopic and mesopic pupil size significantly but did not increase wavefront aberrations notably. Increased pupil size may be due to increased sympathetic activity during pregnancy. And this activity can be noninvasively determined by measuring pupil size.
Therapeutic Advances in Urology | 2017
Hande Husniye Telek; Ömer Gökhan Doluoğlu; Ayse Burcu; Gülizar Demirok; Firdevs Örnek; Ali Ayyildiz
Background: To evaluate the effects of tolterodine on anterior segment and choroidal thickness by using the Pentacam system and optical coherence tomography (OCT) (Pentacam). Methods: A total of 122 eyes of 61 patients (34 female; 27 male) were included in the study. All patients underwent a regular ocular examination and intraocular pressure measurements before and after 3 months of antimuscarinic drug tolterodine treatment, in addition, pupil diameter, anterior chamber depth, anterior chamber volume, anterior chamber angle, and lens thickness were measured through Pentacam (Oculus Inc., Wetzlar, Germany) system. Measurements of choroidal thickness were performed by OCT (Spectralis®, Heidelberg Engineering, Heidelberg, Germany). Results: The mean age was 58.4 ± 7.3 years and 56.5 ± 11.1 years for female and male patients. The mean intraocular pressure was 15.10 ± 2.75 mmHg before treatment and 15.18 ± 2.65 mmHg after treatment. Pupil diameters were 3.09 ± 0.48 mm before treatment and 3.12 ± 0.43 mm after treatment. Anterior chamber depth, before and after treatment were 2.68 ± 0.65 mm and 2.70 ± 0.61 mm. The mean value for subfoveal choroidal thickness was 267.92 ± 81.35 μm before the administration of tolterodine, whereas the mean choroidal thickness was 271.83 ± 75.42 μm after the administration of tolterodine. The alterations in the subfoveal choroidal thickness were not statistically significant (p = 0.862). Conclusions: After 3 months of therapy with tolterodine, there were no significant changes in anterior segment parameters and choroidal thickness.
Seminars in Ophthalmology | 2017
Gülizar Demirok; Mehmet Fatih Kocamaz; Yasemin Topalak; Yeşim Altay; Burcu Tabakci; Ahmet Şengün
ABSTRACT Purpose: To evaluate the changes in the macular ganglion cell complex (GCC) thickness and central macular thickness (CMT) as measured by spectral domain optical coherence tomography (OCT) post-argon laser panretinal photocoagulation (PRP). Methods: The medical records of 25 patients with proliferative diabetic retinopathy (PDR) who underwent PRP, 29 patients with non-proliferative diabetic retinopathy (NPDR), and 29 patients with diabetes but without diabetic retinopathy (DR) were analyzed. The patients who received PRP were followed up for one year. The follow-up measurements were evaluated at baseline, and months 1, 6, and 12 post-argon laser PRP. The baseline values of CMT and GCC thickness were compared among the groups to assess changes with PRP therapy. Results: The CMT gradually increased in months 1 and 6 and then decreased; however, it was significantly higher than the baseline value at month 12 in the PDR group post-PRP. The GCC thickness also increased at months 1 and 6 in almost all segments of the macula, but at month 12 decreased to the baseline value. There was no correlation between the increasing thickness of the macula and change in the GCC thickness post-PRP period in the PDR group. In addition, no significant correlation was detected between the GCC thickness and best-corrected visual acuity during all follow-up visits. Conclusions: GCC thickness increased significantly until month 6 compared with baseline values in most of the macular segments post-PRP in the PDR group. The GCC thickness at month 12 was not different from the baseline thickness in any of the macular segments.
Indian Journal of Ophthalmology | 2015
Gülizar Demirok; Mehmet Fatih Kocamaz; Yasemin Topalak; Ahmet Sengun; Berati Hasanreisoglu
A 23-year-old girl presented to the clinic with metamorphopsia and photopsia in her left eye. After detailed ophthalmic examination, central retinal vein occlusion with optic disc edema was detected in that eye. Three days after diagnosis, the patient returned to our clinic with visual acuity decrease. Central retinal artery occlusion sparing cilioretinal artery was detected. All the laboratory tests were normal except for heterozygous methylenetetrahydrofolate reductase mutation (A1298C genotypes) and an indefinite Lyme disease seropositivity. Symptoms and visual disturbance recovered without any further treatment other than acetylsalicylic acid for prophylaxis.
International Ophthalmology | 2018
Umit Eksioglu; Caglar Oktem; Gulten Sungur; Mehmet Yakin; Gülizar Demirok; Firdevs Örnek
Canadian Journal of Ophthalmology-journal Canadien D Ophtalmologie | 2017
Umit Eksioglu; Mehmet Yakin; Gulten Sungur; Banu Satana; Gülizar Demirok; Ozgur Balta; Firdevs Örnek
Cornea | 2018
Mehmet Yakin; Umit Eksioglu; Zuleyha Yalniz-Akkaya; Selma Uzman; Evin Singar-Ozdemir; Kemal Gultekin; Gülizar Demirok; Ilgaz Sagdic Yalvac; Firdevs Örnek; Ayse Burcu