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Dive into the research topics where Muhammed Sahin is active.

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Featured researches published by Muhammed Sahin.


International Journal of Ophthalmology | 2013

Effects of vernal and allergic conjunctivitis on severity of keratoconus

Abdullah Kürşat Cingü; Yasin Çınar; Fatih Mehmet Türkcü; Alparslan Sahin; Seyhmus Ari; Harun Yüksel; Muhammed Sahin; İhsan Çaça

AIM To demonstrate the effects of two different types of allergic conjunctivitis on severity of keratoconus (KC). METHODS We retrospectively reviewed the medical records of 171 KC patients referred between June 2010 and June 2011. The KC patients were divided into 3 groups as KC (group A), KC with vernal keratoconjunctivitis (VKC) (group B) and KC with allergic conjunctivitis (AC) (group C). Main outcome measures were demographic and ocular clinical features including age at presentation, gender, spherical equivalent (SE), best spectacle corrected visual acuity (BCVA), mean keratometric measurement (Km), central corneal thickness (CCT), and intraocular pressure (IOP). Groups were compared in term of study variables. RESULTS The median age at presentation was significantly lower in group B (P<0.001). According to the median SE (P=0.003), BCVA (P=0.022), Km (P<0.001), CCT (P=0.015) and Amsler-Krumeich classification (P<0.001), KC was more severe in group B. There was no significant difference in terms of IOP and corrected IOP among the groups (P=0.44), however there were 4 patients who had increased corrected IOP developed after topical corticosteroid use in group B. The differences among the groups persisted even after controlling for age and gender. CONCLUSION Our findings demonstrated a more severe KC in VKC patients despite their younger age which suggests evaluation of VKC patients as a separate group in keratoconus disease.


Journal of Ophthalmology | 2013

Evaluation of Cystoid Macular Edema Using Optical Coherence Tomography and Fundus Autofluorescence after Uncomplicated Phacoemulsification Surgery

Muhammed Sahin; Abdullah Kürşat Cingü; Nilüfer Gözüm

Aim. To investigate the utility of fundus autofluorescence (FAF) and optical coherence tomography (OCT) in the evaluation of cystoid macular edema (CME) following cataract surgery. Materials and Methods. Forty eyes of 29 patients undergone phacoemulsification, with posterior chamber intraocular lens implantation surgery. Central macular thickness (CMT) of the patients was evaluated using OCT and FAF preoperatively and postoperative 1st, 30th, 60th, 90th, and 180th days. Results. CME was detected in three eyes (7.5%) of two patients using OCT. Hyperautofluorescence (HAF) was detected in two of these three eyes and resolved with treatment. In the remaining 37 eyes without CME, there was a significant increase in visual acuity when compared to preoperative values (P = 0.008) Mean macular thicknesses (MMT) of the eyes without CME were 174 ± 20 μm preoperatively and 179 ± 22 μm at day 1, 178 ± 19 μm at 1st month, and 168 ± 10 μm at 6th month postoperatively. In the eyes with CME, the MMTs, measured with OCT were 189 ± 23 μm preoperatively and 432 ± 361 on day 1, 343 ± 123 μm at 1st month, 345 ± 196 at 2nd month, and 200 ± 36 μm at 6th month postoperatively. Conclusion. We found a moderate increase in CMT in the first 3 months postoperatively, in the eyes without CME which did not cause visual disturbances. FAF is a noninvasive, rapid method for the evaluation and follow-up of CME following cataract surgery.


International Journal of Ophthalmology | 2013

Secondary glaucoma after pediatric cataract surgery

Alparslan Sahin; İhsan Çaça; Abdullah Kürşat Cingü; Fatih Mehmet Türkcü; Harun Yüksel; Muhammed Sahin; Yasin Çınar; Seyhmus Ari

AIM To determine the incidence and risk factors of secondary glaucoma after pediatric cataract surgery. METHODS Two hundred and forty nine eyes of 148 patients underwent cataract surgery without intraocular lens (IOL) implantation (group 1), and 220 eyes of 129 patients underwent cataract surgery with IOL implantation (group 2) retrospectively, were evaluated between 2000 and 2011. The outcome measure was the presence or absence of post-cataract surgery glaucoma, defined as an intraocular pressure (IOP) ≥26mmHg, as measured on at least two occasions along with corneal or optic nerve changes. RESULTS The mean follow-up periods of group 1 and 2 were (60.86±30.95) months (12-123 months) and (62.11±31.29) months (14-115 months) respectively. In group 1, 12 eyes of 8 patients (4.8%) developed glaucoma. None of the patients developed glaucoma after surgery in group 2. The mean age of the patients at the cataract surgery was (2.58±0.90) months (1 month-4 months) and the average period for glaucoma development after surgery was (9.50±4.33) months (4-16 months) in group 1. Three of the 12 glaucomatous eyes were controlled with antiglaucomatous medication and 9 eyes underwent trabeculectomy+mitomycin C surgery. One patient underwent a second trabeculectomy + mitomycin C operation for both of his eyes. CONCLUSION The incidence of glaucoma after pediatric cataract surgery is very low in patients in whom IOL is implanted. The aphakic eyes after pediatric cataract surgery are at an increased risk for glaucoma development particularly if they underwent surgery before 4 months of age.


Cutaneous and Ocular Toxicology | 2014

Topical and subconjunctival ranibizumab (lucentis) for corneal neovascularization in experimental rat model

Fatih Mehmet Türkcü; Yasin Çınar; Gül Türkcü; Alparslan Sahin; Abdullah Kürşat Cingü; Hatice Yüksel; Muhammed Sahin; Adnan Yıldırım; İhsan Çaça

Abstract Purpose: To compare the effectiveness of the topical and subconjunctival (SC) ranibizumab treatment in experimental corneal neovascularization (NV) model in rats. Methods: A model of NV was generated by cauterizing right corneas of 30 Sprague-Dawley rats with silver nitrate. The animals were separated into five groups randomly. first group (control group) received topical artificial tear drops two times daily while second and third groups received topical ranibizumab four times daily at concentrations of 5 mg/mL and 10 mg/mL, respectively. Forth and fifth groups were given 0.5 mg/0.05 mL and 1 mg/0.1 mL of SC ranibizumab in the 1st, 3rd and 7th days. The measurements (percentage of NV area and number of vessels) from digital photographs of the corneas were determined and analyzed using analysis software (ImageJ, v1.38). The animals were sacrificed on the 10th day and their corneas were subjected to hemotoxylin-eosin histopathological staining and antisera against CD34 and von-Willebrand factor to evaluate microvascular structures immunohistochemically. Results: The percentage of the corneal NV area and number of vessels in all treatment groups was found to be significantly lower than the control group. There was no significant difference in relation to the percentage of NV area and number of vessels in the treatment groups. Score of the corneal edema was determined to be significantly less in the groups that undertook treatment. Number of vessels and inflammatory cells were significantly lower in the histological and immunohistochemical sections in the treated groups than in the control group. In all treatment groups, fibroblast intensity was significantly lower than the control group (p = 0.005). Conclusion: Topical or SC administration of ranibizumab seems to be a promising and effective medication in the treatment of corneal NV. Further research is recommended to assess the potential side effects and effective dose.


Cutaneous and Ocular Toxicology | 2014

Evaluation of retinal nerve fiber layer thickness in vernal keratoconjunctivitis patients under long-term topical corticosteroid therapy

Abdullah Kürşat Cingü; Yasin Çınar; Fatih Mehmet Türkcü; Nedime Sahinoglu-Keskek; Alparslan Sahin; Muhammed Sahin; Harun Yüksel; İhsan Çaça

Abstract Purpose: The aim of this study was to evaluate the retinal nerve fiber layer (RNFL) thickness in vernal keratoconjunctivitis (VKC) patients who were under long-term topical corticosteroid therapy. Methods: Thirty-six eyes of 36 VKC patients with clear cornea and normal videokeratography and 40 eyes of 40 age- and gender-matched normal children were included in the study. Clinical and demographic characteristics of the patients were noted and detailed ophthalmological examination was performed. Visual acuity (VA), spherical equivalent (SE), axial length (AL) and RNFL thickness measurements were compared between the groups. To correct ocular magnification effect on RNFL, we used Littmann’s formula. Results: All VKC patients had history of topical corticosteroid use and the mean duration of the topical corticosteroid use was 23.8 ± 9.09 months. There was no significant difference between the groups in terms of intraocular pressure (IOP). VKC group had significantly worse VA, greater SE and AL and thinner mean global, superior and inferior RNFL thickness. There were significant negative correlations between the duration of topical corticosteroid use and the mean global, superior and temporal RNFL thickness in VKC group. After correction of magnification effect, VKC group still had thinner mean global, superior and inferior RNFL thickness, and significant difference between the groups in inferior RNFL thickness did not disappear. Conclusion: Significant RNFL thickness difference between the groups suggests a possible effect of long-term corticosteroid use in VKC patients. Because visual field (VF) analysis in pediatric patients is difficult to perform and IOP may be illusive, RNFL thickness measurements in addition to routine examinations in VKC patients may help clinicians in their practice.


Turkish journal of trauma & emergency surgery | 2013

Demographic and etiologic characteristics of children with traumatic serious hyphema

Fatih Mehmet Türkcü; Harun Yüksel; Alparslan Sahin; Kürşat Cingü; Seyhmus Ari; Yasin Çınar; Muhammed Sahin; Adnan Yıldırım; İhsan Çaça

BACKGROUND We aimed to evaluate the etiologic factors, complications, follow-up, and treatment outcomes in serious hyphema following blunt ocular trauma in childhood. METHODS The medical records of 136 patients diagnosed as grade 3 or 4 hyphema due to blunt ocular trauma between January 2006 and December 2011 were evaluated. Visual acuity (VA), complications, and medical and surgical treatments were analyzed. Factors affecting visual prognosis were compared in grade 3 and 4 hyphema cases. RESULTS The mean age of patients was 9.7±4 years. Etiologic factors for trauma were stone in 53 (39%), bead bullet in 25 (18.4%) and others in 58 (42.6%) patients. The most common complication of grade 3 and 4 hyphema was traumatic mydriasis (19.1%), followed by cataract (9.6%) and glaucoma (5.1%). Medical treatment was successful in 114 (83.8%) patients, and 22 (16.2%) patients underwent surgery. Mean initial and final VA of grade 4 patients were found to be significantly lower than those of grade 3 patients. CONCLUSION In grade 3 and 4 hyphema due to blunt trauma, visual prognosis worsened in the presence of additional ocular pathologies. Considering the bad visual prognosis of severe hyphema patients, prompt treatment and close follow-up may prevent complications resulting in poor VA.


Arquivos Brasileiros De Oftalmologia | 2016

The effects of delivery type and gender on intraocular pressure and central corneal thickness in newborns

Zeynep Özkurt; Selahattin Balsak; Berrin Balsak; Hande Guclu; Muhammed Sahin; Harun Yüksel; Fatih Mehmet Türkcü

PURPOSE To analyze intraocular pressure (IOP) and central corneal thickness (CCT) in newborns during the first 12 h of life. METHODS Forty-three newborns born by vaginal delivery (VD) and 30 newborns born by cesarean section (CS) were evaluated. IOP and CCT were measured using Tono-Pen and handheld pachymeter, respectively, at both the 5th minute after delivery and at the 12th h of life. RESULTS The mean IOP for the VD group was significantly higher than that of the CS group at both the 5th minute and 12th h (p =0.042 and p =0.018, respectively). In both groups, the IOP decreased by the 12th h, but the decrease was only significant for the CS group (p =0.020). The decrease in CCT over the 12 h was significant for both groups (p <0.001). In the VD and CS groups, the IOP values of the males were significantly higher than those of the females at the fifth minute only (p =0.024 and p =0.043, respectively). No other values were significantly different between the genders. CONCLUSIONS Newborn IOP is affected by the mode of delivery and gender. A higher IOP was found in vaginally delivered newborns than in CS newborns for at least 12 h postpartum. CCT showed a significant decline within 12 h. Male newborns have significantly higher IOP values in the first minutes of life.


Turkish journal of trauma & emergency surgery | 2014

Etiology and prognosis of penetrating eye injuries in geriatric patients in the Southeastern region of Anatolia Turkey.

Harun Yüksel; Fatih Mehmet Türkcü; Yasin Çınar; Abdullah Kürşat Cingü; Alparslan Sahin; Muhammed Sahin; Zeynep Özkurt; Mehmet Murat; İhsan Çaça

BACKGROUND The purpose of this study was to evaluate the etiologic and prognostic factors of open eye injuries in geriatric patients in the Southeastern region of Anatolia. METHODS Forty-five geriatric patients who underwent surgery for an open eye injury in our clinic between the years of 2008 and 2012 were evaluated retrospectively. Age, gender, cause and the mechanism of the trauma, visual acuity (VA), and the time between the trauma and the surgery were obtained from files and evaluated. RESULTS The mean age of the patients was 70.4±8.2 (65-90) years. Thirty-four of the cases were male and 11 were female. The most frequent mechanism of trauma was a wood strike, while the second most common one was injury with a knife. Corneoscleral penetration was the most frequently observed trauma. The mean VA of the patients was 2.26±0.65 at admission, and was 1.53±0.99 logarithm of the minimum angle of resolution at the final evaluation. The most frequent complications of trauma were iris prolapse and hyphema. There was a significant correlation between the first and final VA. CONCLUSION Penetrating ocular injuries are seen less frequently among geriatric patients, and their prognosis may be worse due to less-efficient wound site healing and differences in scleral rigidity. The most important factor affecting the final VA measurement was the VA of the patient at admission.


European Journal of Ophthalmology | 2014

Author reply to: Mean platelet volume in pseudoexfoliation syndrome and glaucoma.

Fatih Mehmet Türkcü; Hatice Yüksel; Alparslan Sahin; Yasin Çınar; Kürşat Cingü; Muhammed Sahin; Adnan Yıldırım; İhsan Çaça

We are pleased with the interest in our article and appreciate the comments that complement the presented article and provide useful information. This was a retrospectively designed study and any patient with a known systemic disease that may affect the value of MPV was excluded. As we mentioned in the study, because we excluded patients with liver and renal diseases, other blood parameters were in the normal range, so we did not need to provide them in the article. Although some studies report better results with citrate, others report similar results with with citrate and EDTA. (1-4). However, due to the retrospective study design, we used tubes with EDTA, which is routinely used in our laboratory. As mentioned in the article, blood parameters were analyzed within 1 hour following blood draw. Financial Support: No financial support was received for this submission.


International Ophthalmology | 2014

Keratouveitis caused by Euphorbia trigona sap

Yasin Çınar; Fatih Mehmet Türkcü; Abdullah Kürşat Cingü; Harun Yüksel; Muhammed Sahin; Alparslan Sahin

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