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Dive into the research topics where Orhan Baykal is active.

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Featured researches published by Orhan Baykal.


Clinical Biochemistry | 2000

Serum 1,25 dihydroxy vitamin D (1,25(OH)2D3), 25 hydroxy vitamin D (25(OH)D) and parathormone levels in diabetic retinopathy.

Hülya Aksoy; Fatih Akcay; Naciye Kurtul; Orhan Baykal; Bahattin Avci

OBJECTIVES To investigate whether there is a relationship between serum 1,25 dihydroxy vitamin D3 [1,25(OH)2D3], which is an inhibitor of angiogenesis, concentrations and severity of diabetic retinopathy (DR). DESIGN AND METHODS Serum 1,25(OH)2D3, 25 hydroxy vitamin D [25(OH)D] and parathormone (PTH) concentrations were measured in diabetic patients (n = 66) and nondiabetic healthy subjects (n = 20). RESULTS The mean serum 1,25(OH)2D3 concentration in diabetic patients was lower than that in nondiabetics (57.3+/-21.44 vs. 89.4+/-18.01 pmol/L, p<0.001); mean 1,25(OH)2D3 concentrations fell with increasing severity of DR [being 63.4+/-17.26 pmol/L for background DR (BDR), 47.7+/-13.27 pmol/L for preproliferative DR (pre-PDR), and 43.1+/-19.45 pmol/L for proliferative DR (PDR)]. Compared with the control group, serum 25(OH)D concentrations were found to be decreased in diabetic patients (p<0.001). There were negative correlations between 1,25(OH)2D3 and age (r = -0.331, p<0.01) and duration of diabetes (r = -0.255, p<0.05). CONCLUSION From these findings, it was found that there was an inverse relationship between the severity of the retinopathy, i.e., neovascularization, and serum 1,25(OH)2D3 concentrations, being the lowest in PDR and the highest in diabetic patients without retinopathy (NDR) patients. The measurement of serum 1,25(OH)2D3 concentrations might be helpful to predict severity of DR in patients with diabetes mellitus.


Acta Ophthalmologica | 2010

Oxidative DNA damage in patients with cataract

Orhan Ates; Hakan Hamit Alp; Ibrahim Kocer; Orhan Baykal; İlknur Akyol Salman

Acta Ophthalmol. 2010: 88: 891–895


Journal of Ocular Pharmacology and Therapeutics | 2010

Efficacy of Topical N-Acetylcysteine in the Treatment of Meibomian Gland Dysfunction

İlknur Akyol-Salman; Sedat Azizi; Uğur Mumcu; Orhan Baykal

PURPOSE To evaluate the efficacy of topical N-acetyl-cysteine (NAC) therapy in patients with meibomian gland dysfunction (MGD). METHODS Twenty patients with MGD were prospectively randomized and assigned into 2 groups. The patients were instructed to use either NAC 5% or preservative-free artificial tear topically 4 times a day for a month. All patients were instructed to apply lid hygiene once daily. Preservative-free artificial tears treated group served as control. Paired sample Students t-tests were used to detect differences between the baseline and 1 month after treatment initiation in mean ocular symptoms, fluorescein break-up time (FBUT) values, and Schirmer scores in each group. Difference in mean ocular symptoms, Schirmers test scores, and FBUT values between the baseline and 1 month after treatment initiation were compared between the groups using Mann-Whitney U test. RESULTS One month of topical NAC therapy provided statistically significant improvements in FBUT and Schirmer scores as compared with the initial study visit. The average Schirmer increase rate was significantly better in the NAC group than in the control group. Significant improvements for the symptoms of ocular burning, foreign body sensation, and intermittent filmy or blurred vision were noted in both groups; and only NAC-treated group showed improvement for the symptom of itching, at 1 month as compared with 1 day. NAC provided significantly better improvement in itching symptom when compared with controls. CONCLUSIONS Topical administration of NAC is thought to be effective and well tolerated in patients with MGD.


Vision Research | 2003

Correlation between hand preference and intraocular pressure from right- and left-eyes in right- and left-handers

Şenol Dane; Kenan Gumustekin; Ahmet Taylan Yazici; Orhan Baykal

To test whether there is a relationship between handedness and the intraocular pressure and there is a lateralization in the intraocular pressure, the intraocular pressures of the right- and left-eyes were compared in right- and left-handed students. The intraocular pressures were higher in the right-eye than in the left-eye in men, right-handers, and right-eyed subjects; there was no right-left difference in females, left-handers, left-eyed, and both-eyed subjects. The intraocular pressure of right- and left-eyes was higher in left-handers than right-handers. And there were significant negative correlations between hand preference and the intraocular pressure of both right- and left-eyes. We have concluded that the dominant eye has higher intraocular pressure compared to the nondominant one, and there is a relationship between hand preference and the intraocular pressure.


Advances in Therapy | 2007

Conjunctival Flora in Patients With Type 1 or Type 2 Diabetes Mellitus

Habib Bilen; Orhan Ates; Neslihan Astam; Hakan Uslu; Güngör Akçay; Orhan Baykal

Patients with diabetes mellitus (DM) are prone to infection because glucose in the skin, urine, mucous membranes, and tears promotes growth of microorganisms. Conjunctival flora develops soon after birth, and some saprophytic conjunctival flora play a pathogenic role when immune function is compromised, which can lead to serious infection. DM is one condition that may compromise immune status. In lacrimal function tests of DM patients, a decrease in breakup time (BUT) of lacrimal film and a decrease in Schirmer’s test results were seen. In the present study, conjunctival flora in patients with DM was compared with that in controls with regard to type and duration of diabetes and results of lacrimal function tests. Seventeen patients with type 1 DM (n=34 eyes), 66 patients with type 2 DM (n=132 eyes), and 50 control subjects (n=100 eyes) were included. The control group consisted of age-matched patients with no ophthalmologic problems other than refractive error. Clycosylated hemoglobin values were measured with highpressure liquid chromatography with the Hi-AUTOA1c analyzer (Kyoto Daiichi Kagatu Co., Ltd., Kyoto, Japan). Type and duration of diabetes and demographic data were recorded, and routine ophthalmologic examinations were performed; the BUT of lacrimal film was determined, and the results of Schirmer’s test were assessed. Microbiologic sampling was performed twice for both eyes with sterile cotton swabs. One sample was incubated in 2 mL of brain-heart infusion broth agar; the other was incubated for the presence of fungi in Sabouraud dextrose agar. Colony morphology, hemolysis, and Cram’s stain, as well as catalase, oxidase, and coagulase tests were performed. No growth was observed in 12 of 1 7 patients (35.4%) with type 1 DM, 28 of 66 patients (21.2%) with type 2 DM, and 25 of 50 control subjects (50%).Staphylococcus epidermidis (11.79%) andStaphylococcus aureus (11.7%) were the most frequently isolated organisms in the type 1 DM group, and Sepidermidis (24.2%) and Saureus (21.2%) were the predominant organisms in the type 2 DM group. In control subjects, Sepidermidis (22%), Saureus (12%), andCorynebacterium spp (10%) were the most frequently isolated organisms, and the number of eyes with growth of Saureus was significantly higher in the type 2 DM group than in the other groups (P<.01). Patients with diabetes are more prone to postoperative endophthalmitis than are nondiabetics, and preoperative application of antiseptic or antimicrobial agents to the conjunctiva may not sterilize the area. Impaired integrity of the posterior capsule may also increase the risk of endophthalmitis. Postoperative endophthalmitis is usually associated with gram-positive organisms (75%–80%); gram-negative organisms (15%–29%) and fungi (3%–13%) account for a smaller number of cases. A high rate of resistance to penicillin, ampicillin, and tetracycline was observed in Saureus isolates, although resistance to vancomycin was absent, rendering this molecule the most effective therapeutic option. In this study, Sepidermidis and Saureus were the 2 most frequently isolated organisms in patients with DM. It is concluded that the conjunctival flora in diabetic subjects differs from that in nondiabetic subjects. This should be considered preoperatively and postoperatively, and prophylactic and postoperative treatment should be administered accordingly to diabetic patients.


European Journal of Ophthalmology | 2009

Oxidative DNA damage in retinopathy of prematurity

Orhan Ates; H. Hakan Alp; Caner I; Yildirim A; Tastekin A; Ibrahim Kocer; Orhan Baykal

Purpose This study examines the levels of oxidative damage in patients with retinopathy of prematurity (ROP). Methods Fifty patients were recruited with a birthweight below 1500 g or gestational age below 32 weeks. The cases were classified into those who developed ROP (n=25) and those without ROP (n=25). The authors obtained blood and urine samples from each infant, for measuring 8-hydroxy 2-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) levels, at the time of the first examination at 4–6 postnatal weeks. Results A significant difference was observed in leukocyte and urine 8-OHdG levels in patients with ROP compared to those without ROP (p<0.001 for both). Similarly, a significant difference was observed in plasma and urine MDA levels in patients with ROP compared to those without ROP (p<0.001 for both). In addition, significant correlations were found between levels of 8-OHdG in leukocyte DNA and plasma MDA (r=0.859, p<0.001), and between levels of urine 8-OHdG excretion and urine MDA (r=0.563, p<0.001). Conclusions 8-OHdG in leukocyte DNA and urine levels in premature infants can be useful as an indicator for ROP screening.


Journal of Ocular Pharmacology and Therapeutics | 2012

Comparison of the Efficacy of Topical N-Acetyl-Cysteine and a Topical Steroid-Antibiotic Combination Therapy in the Treatment of Meibomian Gland Dysfunction

İlknur Akyol-Salman; Sedat Azizi; Uğur Mumcu; Orhan Ates; Orhan Baykal

PURPOSE This study aimed to compare the efficacy of topical N-acetyl-cysteine (NAC) with a topical steroid-antibiotic combination, betamethasone-sulfacetamide sodium therapy in patients with meibomian gland dysfunction (MGD). METHODS Twenty patients with MGD were prospectively randomized and assigned into 2 groups. The patients were instructed to use either NAC 5% or a topical steroid-antibiotic combination, betamethasone 0.1%-sulfacetamide sodium 10%, topically 4 times a day for a month. All patients were instructed to apply lid hygiene once daily. RESULTS One month of topical therapy provided statistically significant improvements in fluorescein break-up time and Schirmer scores as compared with the initial study visit in both groups (P≤0.001). Significant improvements for the symptoms of ocular burning, itching, and intermittent filmy or blurred vision were noted in both groups at 1 month as compared with 1 day (P<0.05). Considering these rates, there was no significant difference between the groups (P>0.05). None of the patients developed an allergic reaction to the medications, and intraocular pressure measurements were within the normal limits in both groups. CONCLUSION When used in conjunction with eyelid hygiene, topical administration of NAC appears to be as effective as a topical steroid-antibiotic combination, betamethasone-sulfacetamide sodium therapy in patients with MGD.


International Journal of Ophthalmology | 2013

Plasma coenzyme Q10 levels in type 2 diabetic patients with retinopathy.

Orhan Ates; Habip Bilen; Sadullah Keles; H. Hakan Alp; Mevlüt Sait Keleş; Kenan Yildirim; Osman Ondas; L. Can Pınar; Mustafa Civelekler; Orhan Baykal

AIM To determine the relationship between proliferative diabetic retinopathy (PDRP) and plasma coenzyme Q10(CoQ10) concentration. METHODS Patients with type 2 diabetes and PDRP were determined to be the case group (n=50). The control group was consist of healthy individuals (n=50). Plasma CoQ10 and malondialdehyde (MDA) levels were measured in both groups. RESULTS Ubiquinone-10 (Coenzyme Q10) levels in PDRP and control subjects are 3.81±1.19µmol/L and 1.91±0.62µmol/L, respectively. Plasma MDA levels in PDRP and control subjects were 8.16±2µmol/L and 3.44±2.08µmol/L, respectively. Ratio of Ubiquinol-10/ubiquinone-10 in PDRP and control subjects were 0.26±0.16 and 1.41±0.68, respectively. CONCLUSION The ratio of ubiquinol-10/ubiquinone-10 is found lower in patients with PDRP. High levels of plasma ubiquinol-10/ubiquinone-10 ratio indicate the protective effect on diabetic retinopathy.


Acta Medica (Hradec Kralove, Czech Republic) | 2005

Leukocyte lipid peroxidation, superoxide dismutase and catalase activities of type 2 diabetic patients with retinopathy.

Naciye Kurtul; Ebubekir Bakan; Hülya Aksoy; Orhan Baykal

Increased oxidative stress might play an important role in the initiation and progression of diabetic complications. The present study has been undertaken to investigate whether there is any relationship between retinopathy degree and leukocyte superoxide dismutase (SOD) and catalase (CAT) activities and lipid peroxidation (LPO) in diabetic individuals with type 2 diabetic retinopathy. Patients were groupped with respect to the degree of retinopathy. Leukocyte malondialdehyde (MDA) levels, and SOD and CAT activities were measured in patients with type 2 diabetes mellitus (n=41) and nondiabetic healthy controls (n=23). Leukocyte LPO of the type 2 diabetic patients with retinopathy was significantly increased (p < 0.001), whereas SOD and CAT activities were decreased (p<0.001 and p<0.001, respectively) compared to those of controls. MDA concentrations rose while SOD and CAT activities fell with increasing severity of diabetic retinopathy, altough there was no significant difference in comprasion of the parameters mentioned above between the diabetic patients with and without retinopathy. Our results show that leukocytes in patients with type 2 diabetic retinopathy are affected by oxidative stress which might be contribute to pathogenesis of diabetic retinopathy. Prospective studies are needed to evaulate the relationship between the leukocyte antioxidants status and DR.


Medical Science Monitor | 2014

Paintball-related ocular trauma: paintball or painball?

Sadullah Keles; Osman Ondas; Metin Ekinci; Mustafa Talip Sener; Erim Erhan; Ahmet Sirinkan; İlknur Akyol Salman; Ibrahim Kocer; Orhan Baykal

Background The aim of this study is to describe the type and severity of paintball-related ocular trauma and to determine the necessary precautions to minimize the risk of ocular injury regardless of whether adequate eye protection was used. Material/Methods A retrospective chart review identified patients treated for paintball-related ocular trauma at the Ataturk University Medical Hospital from June 2010 through March 2013. A descriptive analysis of data was performed. Results Ten patients with paintball-related ocular trauma were identified. At the time of their first examination, 7 of these patients had visual acuity (VA) of 20/200 or worse. One patient had a final VA of no light perception and 4 patients had a final VA of 20/200 or worse. Hyphema was noted in 7 patients, traumatic cataract in 2, iridodialysis in 2, retinal detachment in 3, and secondary glaucoma in 1. Six patients required surgery. Although all victims have used eye protection during the game, all patients were injured after they thought the game was over and had taken off their helmets or eye-protective devices. Conclusions Paintball-related accidents result in serious ocular trauma and most of the patients require surgery. These injuries result in severe loss of VA in some patients. Uninterrupted use of proper eye protection whenever a player is in the game field, even after they believe the game has ended, may reduce the incidence of severe ocular trauma in paintball players.

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