Publications by authors named "Burak Özdemir"

17 Publications

  • Page 1 of 1

New nanodrug design for cancer therapy: Its synthesis, formulation, in vitro and in silico evaluations.

Arch Pharm (Weinheim) 2020 Nov 5;353(11):e2000137. Epub 2020 Aug 5.

Department of Chemistry, Yildiz Technical University, Davutpasa Campus, Istanbul, Turkey.

The aim of this study was to develop a novel nanosize drug candidate for cancer therapy. For this purpose, (S)-methyl 2-[(7-hydroxy-2-oxo-4-phenyl-2H-chromen-8-yl)methyleneamino]-3-(1H-indol-3-yl)propanoate (ND3) was synthesized by the condensation reaction of 8-formyl-7-hydroxy-4-phenylcoumarin with l-tryptophan methyl ester. Its controlled release formulation was prepared and characterized by different spectroscopic and imaging methods. The cytotoxic effects of ND3 and its controlled release formulation were evaluated against MCF-7 and A549 cancer cell lines, and it was found that both of them have a toxic effect on cancer cells. For drug design and process development, the molecular docking analysis technique helps to clarify the effects of some DNA-targeted anticancer drugs to determine the interaction mechanisms of these drugs on DNA in a shorter time and at a lower cost. By using the molecular docking analysis and DNA binding assays, the interaction between the synthesized compound and DNA was elucidated and non-binding interactions were also determined. To predict the pharmacokinetics, and thereby accelerate drug discovery, the absorption, distribution, metabolism, excretion and toxicity values of the synthesized compound were determined by in silico methods.
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http://dx.doi.org/10.1002/ardp.202000137DOI Listing
November 2020

Synthesis, characterization, biological activities and molecular docking of Epilobium parviflorum aqueous extract loaded chitosan nanoparticles.

Int J Biol Macromol 2020 Oct 13;161:947-957. Epub 2020 Jun 13.

Yildiz Technical University, Faculty of Chemical and Metallurgical Engineering, Department of Bioengineering, 34220 Istanbul, Turkey.

Epilobium is a medicinal plant; its extracts are widely used traditional medicine due to their broad range of pharmacological and therapeutic properties. Its most prominent feature is its therapeutic effects on prostatic diseases. The aim of this study is preparation of controlled release system of Epilobium parviflorum, and determination of its potential of anticancer applications. For this purpose, Epilobium parviflorum extract (EPE) loaded chitosan nanoparticles were prepared with ionic gelation method to increase the bioavailability of the extract. The nanoparticles were investigated in terms of size, zeta potential, polydispersity index, encapsulation efficiency, loading capacity and release profile. Besides, scanning electron microscopy (SEM) was used to observe the morphology of the nanoparticles. Moreover, Ames/Salmonella test was used to determine the mutagenicity of EPE, and it was shown that it had no mutagenic effect. It was found that EPE loaded chitosan nanoparticles were with 64.47 nm in average size, 0.168 PdI and 15.2 mV zeta potential. Encapsulation efficiency and loading capacity were found as 92.46% and 8%, respectively. Finally, DNA binding assay and in silico molecular docking studies were performed between EPE and DNA in order to contribute to design of plant based controlled release system for use in cancer therapy.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.06.066DOI Listing
October 2020

Cranio-Orbital Tumors: Clinical Results and A Surgical Approach.

Sisli Etfal Hastan Tip Bul 2019 27;53(3):240-246. Epub 2019 Aug 27.

Department of Neurosurgery, Sisli Etfal Training and Research Hospital, Istanbul, Turkey.

Objectives: In this study, we aimed to share the surgical approaches and clinical experiences of cranio-orbital tumors, which are surgically difficult anatomies.

Methods: A total of 22 orbital tumors with extraorbital-transcranial pathology between January 2004 and December 2017 were retrospectively reviewed. Information was obtained from hospital, operation and outpatient records for this study. Preoperative demographic data, ophthalmologic examination findings, clinical and radiological findings were recorded. All patients had cranial magnetic resonance and cranial computerised tomography examinations at this time. The location of the tumor, its size and its relation to neighboring structures were recorded in the light of these examinations.

Results: The lateral approach was performed in 12 cases. The lateral approach was performed with frontotemporal craniotomy. Because of the lateral inferior location of the tumor in three of 12 cases, zygoma osteotomy was added to classical osteotomy. In 10 cases, the anterior approach was applied and the frontal craniotomy was found sufficient in seven cases. In three cases subfrontal craniotomy was added to classical craniotomy.

Conclusion: The findings obtained in this study suggest that high resection rates can be achieved with appropriate surgical intervention in orbital tumors requiring a transcranial surgical approach. The most important factor in surgical planning is the location of the tumor. The size of the tumor and the expectation of the percentage of surgical removal are the other important factors. In our series, it has reached high excision ratio in most cases with low complication rate, good visual field and eye movements results.
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http://dx.doi.org/10.14744/SEMB.2018.82698DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7192274PMC
August 2019

Factors associated with mortality in acute subdural hematoma: Is decompressive craniectomy effective?

Ulus Travma Acil Cerrahi Derg 2019 Mar;25(2):147-153

Department of Neurosurgery, University of Health Sciences, Şişli Hamidiye Etfal Training and Research Hospital, İstanbul-Turkey.

Background: Despite rapid diagnosis and aggressive neurosurgical intervention, acute subdural hematoma (ASDH) is a severe type of head injury that can result in high morbidity and mortality. Although surgical procedures, such as craniotomy and decompressive craniectomy (DC), can be effective, the preferred approach for treating an ASDH remains controversial. The aim of this report was to evaluate factors associated with mortality in patients with ASDH and determinants of outcome in those with ASDH who underwent DC.

Methods: The demographic details and clinical and radiological characteristics of a total of 93 patients with ASDH who underwent DC during a 60-month period from 2012 to 2017 were evaluated to determine the effect on mortality and any association with the Glasgow Coma Scale (GCS) score recorded on arrival.

Results: Sixty-five male and 28 female subjects with a mean age of 59.82+-19.49 years (range: 16-88 years) were included in the study. Sixteen patients (17.2%) died following the surgery. Older age (p=0.007) and lower GCS scores (p=0.022) were statistically significantly associated with the mortality rate. The mean hematoma thickness was 15.46+-5.73 mm, and the mean midline shift was 9.90+-4.84 mm. The mortality rate was positively correlated with an excessive midline shift (p=0.011; r=0.262) and age (p=0.022; r=0.237) in patients with ADSH. A midline shift of ≥10 mm and a hematoma thickness of ≥15 mm was significantly associated with mortality (p=0.014; p=0.039). The etiology of the trauma; comorbidities of subarachnoid, epidural, or intracranial hemorrhage; compression fractures; or contusions were not significantly correlated.

Conclusion: The results indicated that there was a higher mortality rate among older patients and those with a GCS score of <6 on arrival. A midline shift of ≥10 mm and a hematoma thickness of ≥15 mm were significantly related to mortality. Our study supports the conclusion that DC may help prevent further midline shift and be associated with a lower mortality rate compared with a craniotomy.
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http://dx.doi.org/10.5505/tjtes.2018.48079DOI Listing
March 2019

Timing of Decompressive Craniectomy for Malignant Middle Cerebral Artery Infarction: A Single-Center Analysis.

Medicina (Kaunas) 2019 Jan 30;55(2). Epub 2019 Jan 30.

University of Health Sciences, Şişli Hamidiye Etfal Training and Research Hospital, Department of Neurosurgery, Istanbul 34371, Turkey.

: Malignant middle cerebral artery infarction (MMCAI) usually leads to brain edema that may result in transtentorial herniation and brainstem compression. The prognosis of MMCAI is generally poor. The aim of this study was to discuss our experience with surgical decompression for MMCAI, and determine the association between timing of craniectomy and neurological outcomes. We identified consecutive patients diagnosed with MMCAI who underwent decompressive craniectomy (DC). Clinical and demographic data were obtained from electronic medical records, including: age, sex, preoperative Glasgow Coma Scale (GCS) score, surgery timing, postoperative GCS scores, and modified Rankin Scale (mRS) scores. This study included 27 stroke patients (aged 38⁻80 years) operated within 72 h of the onset of neurological symptoms. Sixteen, five, and six patients underwent DC within 24 h, between 24 and 48 h, and after 48 h after onset of symptoms, respectively. Five patients died after the surgery. Patients who underwent DC within 24 h and 24⁻48 h had better mean GCS scores than those who underwent DC after 48 h ( = 0.000, = 0.015). In addition, patients who underwent DC within 24 h had better mean postoperative mRS scores ( = 0.000) than other patients. Patients older than 60 years had significantly lower GCS scores ( = 0.027) and higher mRS scores ( = 0.033) than younger patients. Our findings support that DC had satisfying outcomes in patients who underwent DC within 24 h. Older age and lower Glasgow Coma Scale scores among DC patients with MMCAI are associated with high morbidity and mortality.
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http://dx.doi.org/10.3390/medicina55020031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6409760PMC
January 2019

Management of Craniopharyngioma.

J Craniofac Surg 2019 Mar/Apr;30(2):e178-e183

Department of Pathology, Şişli Hamidiye Etfal Training and Research Hospital, University of Health Sciences, Istanbul, Turkey.

Objective: Craniopharyngiomas are one of the most challenging problems for neurosurgeons because of the high recurrence rates due to their localization and associated endocrinological disorders. This study reports the outcomes of surgeries and recurrence rates of 45 craniopharyngioma cases.

Method: Patients who were diagnosed with craniopharyngioma in the authors' clinic between 1998 and 2016 evaluated retrospectively.

Results: A total of 45 patients (25 males and 20 females; age, 3-56 years) who had previously undergone surgery for craniopharyngioma were enrolled and followed up for 12 to 222 months (mean follow-up duration, 73.5 ± 55.2 months). Among these, 25 were children (55.5%) with a mean age of 9.5 ± 4.6 years and 20 were adults (45.5%) with a mean age of 37.2 ± 12.7 years. A total of 39 (86.6%) patients underwent total tumor resection, while 6 (13.4%) underwent subtotal tumor removal. During 12 to 30 months of follow-up, the progression of residual tumor was recorded in 4 patients, 3 of whom underwent surgery and postoperative radiotherapy. Despite the total resection of tumor in their first surgery, 3 patients showed tumor recurrence during 15 to 34 months of the follow-up.

Conclusion: Our findings suggest that the total resection of craniopharyngiomas, when possible, results in a favorable quality of life, with acceptable mortality and morbidity rates.
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http://dx.doi.org/10.1097/SCS.0000000000005136DOI Listing
August 2019

Production and characterization of a conserved M2e peptide-based specific IgY antibody: evaluation of the diagnostic potential via conjugation with latex nanoparticles.

Prep Biochem Biotechnol 2018 2;48(10):930-939. Epub 2018 Nov 2.

c GlaxoSmithKline-Vaccine , Istanbul , Turkey.

Antibodies play an important role in combating and controlling viral diseases such as influenza. Immunoglobulin Y (IgY) antibodies have several advantages such as a less invasive manufacturing process, ease of isolation, higher affinity compared with IgG antibodies, and cost-effectiveness. To date, although specific IgY production has been performed for different strains of influenza A, to the best of our knowledge, an IgY against the M2e peptide has not been produced. In the current study, IgY antibodies are produced, purified, and characterized using the M2e peptide sequence for the first time with the intent to apply them for the diagnosis of influenza A virus. Anti-M2e IgY antibodies are obtained from eggs using a two-step purification method. The activity and characterization of the antibodies are determined using an enzyme-linked immunosorbent assay, a nano-spectrophotometer, an SDS-Page assay, and a Western Blot analysis. Finally, anti-M2e IgY antibodies are conjugated to the latex nanoparticles, and the reaction between the influenza A virus and the nanoparticles is demonstrated using light microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy. In conclusion, this study shows that anti-M2e IgY antibodies can contribute to the diagnosis, treatment, and prevention of the influenza A virus.
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http://dx.doi.org/10.1080/10826068.2018.1525564DOI Listing
February 2019

Cycle length identifies obstructive sleep apnea and central sleep apnea in heart failure with reduced ejection fraction.

Sleep Breath 2018 Dec 10;22(4):1093-1100. Epub 2018 Apr 10.

Clinic for Cardiology, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Georgstraße 11, 32545, Bad Oeynhausen, Germany.

Aim: To clarify whether unmasking of central sleep apnea during continuous positive airway pressure (CPAP) initiation can be identified from initial diagnostic polysomnography (PSG) in patients with heart failure with reduced ejection fraction (HFREF) and obstructive sleep apnea (OSA) MATERIALS AND METHODS: Forty-three consecutive patients with obstructive sleep apnea and central sleep apnea (OSA/CSA) in HFREF were matched with 43 HFREF patients with OSA and successful CPAP initiation. Obstructive apneas during diagnostic PSG were then analyzed for cycle length (CL), ventilation length (VL), apnea length (AL), time to peak ventilation (TTPV), and circulatory delay (CD). We calculated duty ratio (DR) as the ratio of VL/CL and mathematic loop gain (LG).

Results: While AL was similar, CL, VL, TTPV, CD, and DR was significantly longer in patients with OSA/CSA compared to those with OSA, and LG was significantly higher. Receiver operator curves identified optimal cutoff values of 50.2 s for CL (area under the curve (AUC) 0.85, 29.2 s for VL (AUC 0.92), 11.5 s for TTPV (AUC 0.82), 26.4 s for CD (AUC 0.79), and 3.96 (AUC 0.78)) respectively for LG to identify OSA/CSA.

Conclusion: OSA/CSA in HFREF can be identified by longer CL, VL, TTPV, and CD from obstructive events in initial diagnostic PSG. The underlying mechanisms seem to be the presence of an increased LG.
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http://dx.doi.org/10.1007/s11325-018-1652-4DOI Listing
December 2018

Endovascular stent-coiling of a giant basilar artery aneurysm through a previous radial artery bypass.

J Clin Neurosci 2018 May 23;51:100-102. Epub 2018 Feb 23.

Department of Neurological Surgery, University of Washington, Seattle, WA, United States; Department of Radiology, University of Washington, Seattle, WA, United States.

Giant, partially-thrombosed basilar artery (BA) aneurysms are extraordinarily difficult to treat. Due to the high risk of rupture exclusion of these aneurysms from the circulation is imperative. In certain instances, direct clipping is unsuitable, and high-flow bypass and proximal parent vessel clip occlusion is required. We report a case of a recurrent partially-thrombosed giant BA apex aneurysm treated with endovascular stent-coiling through a previous radial artery bypass graft. Following the initial bypass and aneurysm trapping six years prior, the patient was neurologically stable until three months prior to admission when he developed new diplopia and left third nerve palsy. Imaging studies demonstrated interval enlargement of the thrombosed portion of the aneurysm and increased size in the filling portion of the aneurysm. In the present case, the existing radial artery bypass graft between left VA and left PCA permitted successful stent-assisted embolization of the recurrent BA aneurysm. To our knowledge, this is the first published case of endovascular stent-coiling of a BA aneurysm through a radial artery bypass graft. This novel technique can be a useful alternative for endovascular aneurysm treatment in these challenging lesions.
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http://dx.doi.org/10.1016/j.jocn.2018.02.004DOI Listing
May 2018

Tunable Broadband Nanocarbon Transparent Conductor by Electrochemical Intercalation.

ACS Nano 2017 01 4;11(1):788-796. Epub 2017 Jan 4.

Department of Physics and Science of Advanced Materials Program, Central Michigan University , Mount Pleasant, Michigan 48859, United States.

Optical transparent and electrical conducting materials with broadband transmission are important for many applications in optoelectronic, telecommunications, and military devices. However, studies of broadband transparent conductors and their controlled modulation are scarce. In this study, we report that reversible transmittance modulation has been achieved with sandwiched nanocarbon thin films (containing carbon nanotubes (CNTs) and reduced graphene oxide (rGO)) via electrochemical alkali-ion intercalation/deintercalation. The transmittance modulation covers a broad range from the visible (450 nm) to the infrared (5 μm), which can be achieved only by rGO rather than pristine graphene films. The large broadband transmittance modulation is understood with DFT calculations, which suggest a decrease in interband transitions in the visible range as well as a reduced reflection in the IR range upon intercalation. We find that a larger interlayer distance in few-layer rGO results in a significant increase in transparency in the infrared region of the spectrum, in agreement with experimental results. Furthermore, a reduced plasma frequency in rGO compared to few-layer graphene is also important to understand the experimental results for broadband transparency in rGO. The broadband transmittance modulation of the CNT/rGO/CNT systems can potentially lead to electrochromic and thermal camouflage applications.
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http://dx.doi.org/10.1021/acsnano.6b07191DOI Listing
January 2017

Potassium Ion Batteries with Graphitic Materials.

Nano Lett 2015 Nov 30;15(11):7671-7. Epub 2015 Oct 30.

Department of Physics and Science of Advanced Materials Program, Central Michigan University , Mount Pleasant, Michigan 48859, United States.

Graphite intercalation compounds (GICs) have attracted tremendous attention due to their exceptional properties that can be finely tuned by controlling the intercalation species and concentrations. Here, we report for the first time that potassium (K) ions can electrochemically intercalate into graphitic materials, such as graphite and reduced graphene oxide (RGO) at ambient temperature and pressure. Our experiments reveal that graphite can deliver a reversible capacity of 207 mAh/g. Combining experiments with ab initio calculations, we propose a three-step staging process during the intercalation of K ions into graphite: C → KC24 (Stage III) → KC16 (Stage II) → KC8 (Stage I). Moreover, we find that K ions can also intercalate into RGO film with even higher reversible capacity (222 mAh/g). We also show that K ions intercalation can effectively increase the optical transparence of the RGO film from 29.0% to 84.3%. First-principles calculations suggest that this trend is attributed to a decreased absorbance produced by K ions intercalation. Our results open opportunities for novel nonaqueous K-ion based electrochemical battery technologies and optical applications.
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http://dx.doi.org/10.1021/acs.nanolett.5b03667DOI Listing
November 2015

Hexagonal BC3: A Robust Electrode Material for Li, Na, and K Ion Batteries.

J Phys Chem Lett 2015 Jul 29;6(14):2728-32. Epub 2015 Jun 29.

Department of Physics and Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, United States.

We have investigated the stability, maximum intercalation capacity, and voltage profile of alkali metal intercalated hexagonal BC3 (MxBC3), for 0 < x ≤ 2 and M = Li, Na, and K. Our calculations, based on dispersion-corrected density functional theory, show that these intercalation compounds are stable with respect to BC3 and their bulk metal counterparts. Moreover, we found that among all MxBC3 considered, the maximum stable capacity corresponds to an x value of 1.5, 1, and 1.5 for Li, Na, and K, respectively. These values are associated with large gravimetric capacities of 572 mA h/g for Na and 858 mA h/g for Li and K. Importantly, we show that metal intercalated hexagonal BC3 has the advantage of a small open-circuit voltage variation of approximately 0.49, 0.12, and 0.16 V for Li, Na, and K, respectively. Our results suggest that BC3 can become a robust alternative to graphitic electrodes in metal ion batteries, thus encouraging further experimental work.
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http://dx.doi.org/10.1021/acs.jpclett.5b01110DOI Listing
July 2015

Penetrating keratoplasty in congenital hereditary endothelial dystrophy.

Cornea 2012 Apr;31(4):359-65

Kartal Training and Education Hospital, Second Eye Clinic, Istanbul, Turkey.

Purpose: To compare the results of penetrating keratoplasty (PK) in a series of congenital hereditary endothelial dystrophy (CHED) patients operated at amblyogenic years and at later ages.

Methods: Records of 65 eyes of 35 CHED patients who underwent PK were reviewed retrospectively. Visual results and graft clarity rates were compared between patients operated after (group 1) and before (group 2) 12 years of age. Results were also compared between eyes with and without nystagmus.

Results: Group 1 consisted of 47 eyes (24 patients), whereas group 2 consisted of 18 eyes (11 patients). Thirteen patients (54%) in group 1 and 10 patients (91%) in group 2 had nystagmus. Mean ages at surgery were 26.4 and 7.6 years in group 1 and group 2, respectively. Mean follow-up period was 101.0 months in group 1 and 59.7 months in group 2. Group 1 cases had better graft clarity rates than group 2 cases (P = 0.023). Postoperative best-corrected visual acuities (BCVAs) were 20/80 or better in 39 eyes of group 1 (83%) and in 5 eyes of group 2 (28%). Visual outcomes were found significantly better in group 1 cases (P < 0.001). In group 1, 76% of eyes with nystagmus and 91% of eyes without nystagmus had BCVAs of 20/80 or better. In group 1, both preoperative and postoperative BCVAs were found significantly better in eyes without nystagmus (P < 0.001 and P = 0.002, respectively).

Conclusions: Delayed keratoplasty seems to offer better graft outcomes and visual prognosis to CHED patients, even in the presence of nystagmus.
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http://dx.doi.org/10.1097/ICO.0b013e31823d03afDOI Listing
April 2012

Is pseudoexfoliation syndrome associated with coronary artery disease?

N Am J Med Sci 2010 Oct;2(10):487-90

Department of Cardiology, Kartal Kosuyolu Cardiovascular Research and Training Hospital, Istanbul, Turkey.

Background: Pseudoexfoliation syndrome (PEX) is recognised by chronic deposition of abnormal pseudoexfoliation material on anterior segment structures of the eye, especially the anterior lens capsule. In recent years, several studies have shown the presence of vascular, cardiac and other organ pseudoexfoliative material in patients with ocular pseudoexfoliation.

Aims: The purpose of this study is to determine whether an association exists between ocular pseudoexfoliation and coronary artery disease, aortic aneurysms and peripheric vascular disease.

Patients And Methods: 490 patients who underwent coronary angiography (CAG) at Kosuyolu Cardiovascula Research and Training Hospital were included in the study. Patients were evaluated for conventional risk factors such as age, sex, family history, hypertension, diabetes, dislipidemia and smoking. Detailed eye examinations including evaluation of lens were done in all patients. The presence of PEX material in the anterior segment was best appreciated by slit lamp after pupillary dilation. The patients were divided into two groups according to the presence of PEX, and compared for the presence of CAD and other risk factors.

Results: CAD was present in 387 patients. 103 patients had normal coronary angiography. 20 (5.2 %) of CAD patients and 4 (3.9%) of normal CAG patients were found to have PEX (p>0.05). There was no significant relationship between CAD and the presence of PEX (p>0.05). When patients were grouped according to the presence of PEX, only age was significantly different between the two groups (r: 0.25, p<0.001).

Conclusion: There is no significant relationship between the presence of PEX and CAD. Further studies in larger scales with elderly population may be more valuable.
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http://dx.doi.org/10.4297/najms.2010.2487DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3339112PMC
October 2010

Bilateral conjunctival MALT lymphoma mimicking chronic conjunctivitis.

Onkologie 2010 11;33(6):317-20. Epub 2010 May 11.

Department of Medical Oncology, Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey.

Background: The diagnosis of conjunctival lymphoid tu-mors is straightforward when they present with a characteristic salmon-pink, pebbly, multinodular appearance. However, rarely a diffuse clinical presentation is encountered, and this may mimic chronic conjunctivitis of other etiologies.

Case Report: A 60-year-old man was referred to our clinic with bilateral conjunctival masses in May 2005. With the assumption of chlamydial conjunctivitis, without microbiological or histopathological evidence, tetracycline ointment and oral doxycycline 100 mg twice daily were prescribed. Although a partial response was achieved, 2 months after the treatment, the patient's complaints returned. On second referral to our clinic in March 2006, the patient was re-evaluated. He presented with bilateral conjunctival masses resembling conjunctival lymphoma, and a bilateral diagnostic biopsy was performed. Histopathological evaluation of the biopsy specimens revealed mucosa-associated lymphoid tissue (MALT) lymphoma. The patient received CVP chemotherapy (cyclophosphamide, vincristine, prednisolone). After 6 courses of chemotherapy, he achieved partial remission in both eyes. Currently, 28 months after CVP, sustained remission is obtained.

Conclusions: In these cases, a high index of suspicion is required if one is to avoid a delay in diagnosis, and the importance of correct early diagnosis is obvious.
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http://dx.doi.org/10.1159/000313853DOI Listing
October 2010

Comparison of 2 intrastromal corneal ring segment models in the management of keratoconus.

J Cataract Refract Surg 2010 Jun;36(6):978-85

Dr. Lütfi Kirdar Kartal Training and Research Hospital, Istanbul, Turkey.

Purpose: To compare the outcomes of implantation of 2 models of intrastromal corneal ring segments (ICRS) to manage keratoconus.

Setting: Kartal Training and Research Hospital, Istanbul, Turkey.

Methods: This study evaluated eyes with keratoconus that had implantation of Keraring ICRS (Group A) or Intacs ICRS (Group B). The corneal tunnels were created mechanically or with a femtosecond laser. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, keratometry (K) readings (Orbscan II), and complications in the 2 groups were compared.

Results: Group A comprised 100 eyes and Group B, 68 eyes. The postoperative increase in UDVA and CDVA was statistically significant in both groups (P<.05). Group A had greater improvement in CDVA than Group B at 6 months and 1 year (both P<.001). At 1 year, the decrease in the mean maximum K power was statistically significant in Group A (51.27 diopters [D] +/- 4.46 [SD] to 47.87 +/- 3.39 D) and in Group B (51.12 +/- 4.54 D to 47.58 +/- 3.66 D) (P<.05). The mean reduction in maximum K was statistically significantly greater in Group A at 6 months and 1 year (P = .018 and P = .024, respectively). There were no statistically significant differences in visual or refractive results between femtosecond laser and mechanical tunnel creation.

Conclusion: Although both ICRS models were effective and safe in managing keratoconus, the Keraring ICRS led to more improvement in CDVA and UDVA and a greater reduction in the maximum K value.
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http://dx.doi.org/10.1016/j.jcrs.2009.12.031DOI Listing
June 2010