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Dive into the research topics where Berker Bakbak is active.

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Featured researches published by Berker Bakbak.


Journal of Ocular Pharmacology and Therapeutics | 2013

Comparison of the Effect of Unilateral Intravitreal Bevacizumab and Ranibizumab Injection on Diabetic Macular Edema of the Fellow Eye

Berker Bakbak; Banu Turgut Ozturk; Saban Gonul; Mevlut Yilmaz; Sansal Gedik

PURPOSE To find out whether intravitreally administered bevacizumab and ranibizumab affect the contralateral, untreated, eyes of patients with bilateral diabetic macular edema (DME). METHODS A retrospective review of patients with bilateral DME, who were treated with intravitreal bevacizumab or ranibizumab, was performed. All enrolled patients received intravitreal 1.25 mg bevacizumab or 0.5 mg ranibizumab in the eye with more severe macular edema. As outcome measures, best-corrected visual acuity (BCVA) was assessed with the Early Treatment Diabetic Retinopathy Study chart and central foveal thickness (CFT) measurement was obtained using optical coherence tomography-3 before and at 2 and 4 weeks after injections. RESULTS The study included 55 eyes of 55 patients who received bevacizumab (group 1) and 32 eyes of 32 patients who received ranibizumab (group 2). The mean age of the 55 patients [35 female (63.6%), 20 male (36.4%)] in group 1 was 54.31±12.67 years, and the mean age of the 32 patients [20 female (62.5%), 12 male (37.5%)] in group 2 was 56.01±13.29 years. The median BCVA in the uninjected eye showed no statistically significant change at any visit after either bevacizumab or ranibizumab injection (P=0.302, P=0.582, respectively). In group 1, the median CFT in the uninjected eye was 417 μm at baseline; this was reduced to 401 μm at 2 weeks and 372 μm at 4 weeks. The change in CFT was found to be statistically significant (P=0.009). No statistically significant change was found in the median CFT of uninjected eyes of patients treated with ranibizumab (399, 403, and 407 μm before and at 2 and 4 weeks after treatment, respectively). CONCLUSIONS Compared with ranibizumab, intravitreal administration of bevacizumab resulted in a greater decrease in macular thickness in the untreated eye, in patients with bilateral DME.


British Journal of Ophthalmology | 2013

Comparison of the ganglion cell complex and retinal nerve fibre layer measurements using Fourier domain optical coherence tomography to detect ganglion cell loss in non-arteritic anterior ischaemic optic neuropathy

Saban Gonul; Bengu Ekinci Koktekir; Berker Bakbak; Sansal Gedik

Objective To evaluate the diagnostic ability of macular ganglion cell complex (GCC) and peripapillary nerve fibre layer (NFL) measurements to detect ganglion cell loss (GCL) in patients with non-arteritic anterior ischaemic optic neuropathy (NAION), at the chronic stage. Methods This study included 10 eyes from 10 patients with NAION and 15 eyes from 15 age-matched healthy subjects. The measurements included the GCC thicknesses as average, superior and inferior, the GCC parameters as focal loss volume (FLV) and global loss volume (GLV), the NFL thicknesses as average, superior hemisphere and inferior hemisphere, and the disc parameters as rim area and rim volume. The curves for the area under the receiver operator characteristic (AUROC) were generated to assess the ability of each parameter to detect GCL. Results The patient group had significantly lower GCC thicknesses than the control group (p<0.001, <0.001 and 0.004, for the GCC average, superior and inferior, respectively), and also significantly higher FLV and GLV measurements (p<0.001). The NFL thicknesses were found to be significantly lower in the patient group than the control subjects (p<0.001). Among all the parameters, the FLV and the GLV had the highest levels of AUROC values (1.000, 0.990, respectively). Conclusions The FLV and the GLV showed the strongest abilities to detect GCL in patients with NAION. In addition, peripapillary NFL thickness was comparable to macular GCC thickness in detecting GCL. Therefore, macular GCC scans may provide a good alternative or a complementary practice to NFL scans in the detection of GCL in patients with NAION.


Cornea | 2012

Comparison of central corneal thickness measurements with optical low-coherence reflectometry and ultrasound pachymetry and reproducibility of both devices.

Bengu Ekinci Koktekir; Sansal Gedik; Berker Bakbak

Purpose: To compare the accuracy of optical low-coherence reflectometry (Lenstar LS 900; Haag Streit, Köniz, Switzerland) and conventional ultrasound pachymetry (UP) (US 4000; Nidek, Japan) for measuring central corneal thickness and to assess the interexaminer reproducibilities of both devices. Methods: Department of Ophthalmology, Selcuklu Faculty of Medicine, Selcuk University was the study setting. Central corneal thickness (CCT) was measured in both eyes of 65 emmetropic patients by the same examiner using Lenstar LS 900 noncontact biometry and UP. To assess the interexaminer reproducibility, 2 different examiners consecutively obtained CCT measurements in 16 eyes with Lenstar LS 900 noncontact biometry and UP. Results: Mean CCT measurements with Lenstar LS 900 noncontact biometry and ultrasound biometry were 541.09 ± 33.8 and 545.69 ± 34.0, respectively. Significant correlation was present between these 2 measurements; intraclass correlation coefficient was found to be 95.8% (95% confidence interval: 93.2%–97.4%)(P < 0.001). Interexaminer reproducibility with Lenstar was high, and the intraclass correlation was found to be 99.3% (95% confidence interval: 98.0%–99.7%). We have also investigated the interexaminer reproducibility with UP in these 16 patients, and the results showed a 99.2% (95% confidence interval: 97.7%–99.7%) intraclass correlation. Conclusions: The results of Lenstar LS 900 noncontact biometry correlated with the results of UP. It may be used as an alternative method to UP for measuring CCT. Because of the mild underestimation of CCT by Lenstar, the measurements should be carefully evaluated in patients whose intraocular pressure must strictly be monitored.


Cornea | 2013

The effect of pupil dilation on biometric parameters of the Lenstar 900.

Berker Bakbak; Bengu Ekinci Koktekir; Sansal Gedik; Hüseyin Güzel

Purpose: To evaluate the effect of pupil dilation on the biometric parameters of the Lenstar LS 900 (Haag Streit AG, Koeniz, Switzerland). Methods: In this cross-sectional study of 33 eyes with cataracts, axial length (AL), anterior chamber depth, intraocular lens (IOL) power, keratometry, and pupil diameter measurements were performed using Lenstar biometry before and after pupil dilatation. Intraobserver repeatability was assessed by taking 2 consecutive recordings of biometric parameters using Lenstar biometry in the undilated pupils of 30 eyes with cataracts. Results: The mean difference in AL measurements from intraobserver readings was −0.001 ± 0.01 mm. The study group showed a statistically significant change in the first keratometry reading and anterior chamber depth values (P < 0.05); however, the mean difference in AL and IOL power was statistically insignificant between the undilated and dilated pupil Lenstar biometry readings. Three cases in the study group (9.1%) and 1 case in the control group (3.3%) demonstrated changes in IOL power >0.50 diopter. Conclusions: Dilated and undilated pupil size did not affect the measurement of IOL using the Lenstar biometry.


Clinical and Experimental Ophthalmology | 2012

Bilateral severe anterior uveitis after unilateral selective laser trabeculoplasty.

Bengu Ekinci Koktekir; Sansal Gedik; Berker Bakbak

ing to malignancy was not convincing, and the likely cause for bone growth would be inflammation related to ISOI. In cases of chronic refractory sinusitis, lytic and blastic forms of osteitis occur, and can result in hyperostosis of the nasal and paranasal bones, which was seen in 64% of patients with recurrent rhinosinusitis. The chronic inflammation of ISOI likely caused a corresponding osteitis, an osteoblastic type in this case, producing hyperostosis and the bony changes seen in this case. Diagnosing ISOI is difficult and can further be complicated by the unusual finding of hyperostosis. Treatment of ISOI is controversial as studies using steroids, azathioprine, cyclosporine and radiation have been used with limited success. With our patient’s age and the systemic complications associated with his mesothelioma, treatment was deferred. This case highlights ISOI associated with hyperostosis, and it is important with this presentation that a concomitant work-up for occult malignancy is considered.


Cutaneous and Ocular Toxicology | 2014

Assessment of ocular neurotoxicity in patients treated with systemic cancer chemotherapeutics

Berker Bakbak; Sansal Gedik; Bengu Ekinci Koktekir; Kamil Yavuzer; Baykal Tulek; Fikret Kanat; Esra Pancar

Abstract Purpose: Cisplatin and Paclitaxel are two chemotherapeutic agents known to produce neurotoxicity when used for cumulative dose regimens. In this study we aim to assess their toxicity in the optic nerve, and to evaluate the retinal nerve fibre layer (RNFL) thickness and visual field changes in lung cancer patients treated with Cisplatin and Paclitaxel. Methods: Fifteen patients who were treated intravenously with 75 mg/m2 cisplatin and 175 mg/m2 paclitaxel every 3 weeks, up to a maximum of six courses, were enrolled in this prospective clinical trial. All patients underwent complete ophthalmological assessments before their treatments began, as well as three months after the completion of their treatments. The RNFL thickness measurements were performed using optical coherence tomography (OCT). Functional testing included the use of frequency-doubling technology (FDT) perimetry and the Humphrey visual field analyser (HFA). The main outcome measurements included the average RNFL thicknesses and visual field indices (mean deviation [MD] and pattern standard deviation [PSD]). Results: The median age of the 15 patients (nine male and six female) was 63.49 years old (range: 53–77). The average RNFL thickness measurement during the baseline examination was 103.73 μm (range: 97–111). Three months after the cessation of treatment the RNFL thickness declined to 97.4 μm (range: 91–102). Statistical analysis showed a significant thinning between the two measurements (p = 0.032). The MD and PSD values recorded by the HFA demonstrated no statistically significant changes 3 months after the cessation of treatment (p > 0.207 and p > 0.186, respectively). There were statistically significant decreases in both the MD (0.48 to −1.13 dB) and PSD (2.13 to 0.65 dB) indices measured by the FDT perimetry (p = 0.041 and p = 0.025, respectively). Conclusions: In our study, the systemic administration of Cisplatin and Paclitaxel affected the peripapillary RNFL thicknesses and visual field indices as revealed by FDT perimetry. OCT and FDT perimetry may be adjunctive tools for the screening of ocular toxicity in patients treated with these agents.


Journal of Medical Case Reports | 2012

Cluster headache with ptosis responsive to intranasal lidocaine application: a case report

Berker Bakbak; Sansal Gedik; Bengu Ekinci Koktekir; Mehmet Okka

IntroductionThe application of lidocaine to the nasal mucosal area corresponding to the sphenopalatine fossa has been shown to be effective at extinguishing pain attacks in patients with a cluster headache. In this report, the effectiveness of local administration of lidocaine on cluster headache attacks as a symptomatic treatment of this disorder is discussed.Cases presentationA 22-year-old Turkish man presented with a five-year history of severe, repeated, unilateral periorbital pain and headache, diagnosed as a typical cluster headache. He suffered from rhinorrhea, lacrimation and ptosis during headaches. He had tried several unsuccessful daily medications. We applied a cotton tip with lidocaine hydrochloride into his left nostril for 10 minutes. The ptosis responded to the treatment and the intensity of his headache decreased.ConclusionIntranasal lidocaine is a useful treatment for the acute management of a cluster headache. Intranasal lidocaine blocks the neural transmission of the sphenopalatine ganglion, which contributes to the trigeminal nerve as well as containing both parasympathetic and sympathetic fibers.


Current Eye Research | 2016

Association of Apolipoprotein E Polymorphism with Intravitreal Ranibizumab Treatment Outcomes in Age-Related Macular Degeneration.

Berker Bakbak; Banu Turgut Ozturk; Zamani Ag; Saban Gonul; Iyit N; Sansal Gedik; Yıldırım Ms

Abstract Purpose: Genetic factors are known to influence the response to anti-vascular endothelial growth factor (VEGF) treatment in exudative age-related macular degeneration (AMD). The current study was conducted to investigate the association of Apolipoprotein E (ApoE) polymorphism with the treatment response to ranibizumab for exudative AMD. Methods: One hundred nine eyes (109 patients, 59.6% male, mean age 63.84 ± 7.22 years) treated with intravitreal ranibizumab injections were included in the analysis. Smoking status and lesion type were recorded. Patients were categorized into three groups according to visual acuity (VA) change at 6 months after the first injection: VA loss >5 Early Treatment Diabetic Retinopathy Study (ETDRS) letters (Group 1); VA change between five ETDRS letters gain and loss (Group 2); VA improvement >5 ETDRS letters (Group 3). The association of ApoE gene polymorphisms with the three groups was evaluated. Results: Both smoking status and lesion type showed no significant association with VA change (p = 0.12 and p = 0.64, respectively). A lower frequency of ɛ2 and a higher frequency of ɛ4 were observed in Group 3 (2.9 and 25.7%, respectively). VA improvement with more than five ETDRS letters was significantly associated with the presence of the ɛ4 genotype (p = 0.01). Conclusions: This study demonstrated that carriers of the ApoE ɛ4 polymorphism genotype show demonstrable improvement in VA after treatment with ranibizumab in exudative AMD. ApoE polymorphism identification may be used as a genetic screening to tailor individualized therapeutic approach for optimal treatment in neovascular AMD.


Arquivos Brasileiros De Oftalmologia | 2015

Postoperative fungal endophthalmitis caused by Trichosporon asahii treated with voriconazole

Saban Gonul; Sansal Gedik; Banu Turgut Ozturk; Berker Bakbak; Bengu Ekinci Koktekir; Süleyman Okudan; Hatice Turk Dagi

Postoperative fungal endophthalmitis is a rare but devastating complication of cataract surgery. Vitrectomy and intravitreal amphotericin B injection as well as administration of systemic antifungal agents have been suggested as optimal treatments for fungal endophthalmitis. However, this therapy may fail to eliminate fungal species resistant to current antifungal agents. The saprophytic fungus Trichosporon asahii is frequently observed as a cause of endogenous endophthalmitis in immunosuppressed patients. We report a case of postoperative endophthalmitis caused by T. asahii, resistant to amphotericin B. To the best of our knowledge, this is the first report of T. asahii endophthalmitis successfully treated with intravitreal and systemic voriconazole, pars plana vitrectomy, and removal of the intraocular lens and entire lens capsule.


Ocular Immunology and Inflammation | 2013

Quantitative Assessment of Anterior Chamber Inflammation in Patients with Retained Presumed Intraocular Cotton Fiber after Phacoemulsification

Berker Bakbak; Sansal Gedik; Banu Turgut Ozturk; Bengu Ekinci Koktekir; Saban Gonul; Mevlut Yilmaz

Abstract Purpose: To evaluate anterior chamber inflammation in eyes with retained presumed intraocular cotton fibers after small-incision cataract surgery. Methods: Fourteen patients with retained presumed intraocular cotton fibers after phacoemulsification were evaluated for anterior chamber inflammation. The control group consisted of 15 patients with no postoperative intraocular cotton fibers. An aqueous flare meter was used to evaluate anterior chamber reaction 1 day, 1 week, and 1 month postoperatively. Results: Retained cotton fibers were detected in the anterior chamber in 6 cases, and in the corneal incision site, extending into the anterior chamber, in 8 cases. The mean flare values at each postoperative visit were statistically similar between two groups. Conclusions: Following cataract surgery, retained presumed intraocular cotton fibers did not cause any additional inflammation in the eye within the short term. In contrast to other intraocular foreign bodies, which may cause severe inflammation, retained intraocular cotton fibers seem to be well tolerated following cataract surgery.

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