Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ahmet Akman is active.

Publication


Featured researches published by Ahmet Akman.


Acta Ophthalmologica | 2009

Efficacy of olopatadine HCI 0.1%, ketotifen fumarate 0.025%, epinastine HCI 0.05%, emedastine 0.05% and fluorometholone acetate 0.1% ophthalmic solutions for seasonal allergic conjunctivitis: a placebo-controlled environmental trial.

Mehmet Borazan; Aylin Karalezli; Yonca A. Akova; Ahmet Akman; Halil Kiyici; Selim S. Erbek

Purpose:  We aimed to compare the clinical efficacy and ocular surface variables of olopatadine, ketotifen fumarate, epinastine, emedastine and fluorometholone acetate ophthalmic solutions in preventing the signs and symptoms of seasonal allergic conjunctivitis (SAC).


Journal of Glaucoma | 2010

Aqueous humor and plasma levels of vascular endothelial growth factor and nitric oxide in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

Mehmet Borazan; Aylin Karalezli; Cem Küçükerdönmez; Nilufer Bayraktar; Sevsen Kulaksizoglu; Ahmet Akman; Yonca A. Akova

PurposeTo investigate levels of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in the aqueous humor and plasma of patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG), compared with controls. MethodsThis prospective study involved 37 patients with PXS, 15 with PXG, and 32 control subjects in whom cataract surgery was indicated. Aqueous humor and plasma VEGF and NO levels were measured with enzyme-linked immunosorbent assay and chemiluminescence methods, respectively. ResultsAqueous humor and plasma VEGF concentrations were higher in patients with PXS and PXG than in controls (P<0.001). Aqueous humor NO concentrations were higher in patients with PXS and PXG than in controls (P<0.05 and P=0.001, respectively). Plasma NO concentrations did not differ between the 3 groups. Aqueous humor and plasma VEGF and NO levels were not significantly different in patients with PXS versus PXG. VEGF and NO levels showed no significant correlation among the 3 groups (P>0.05). ConclusionsElevated aqueous humor VEGF and NO levels and plasma VEGF concentrations in eyes with PXS and PXG can be explained by the ischemic nature of these disorders. The lack of correlation between VEGF and NO levels may indicate impaired downregulation, which may have a role in the progression to PXG.


Neuro-Ophthalmology | 1995

Acquired esotropia as presenting sign of cranio-cervical junction anomalies

Ahmet Akman; Volkan Dayanir; Am Sefik Sanaç; Tiilay Kansu

Basilar impression and Arnold Chiari malformation are two congenital cranio cervical junction anomalies that could remain unrecognized until symptoms start at a certain age. Generally the first symptoms are nystagmus and hyperactive deep tendon reflexes. The authors present two cases of acquired esotropia, one with Arnold Chiari malformation and the other with basilar impression together with Arnold Chiari malformation. Divergence palsy is thought to be the underlying mechanism of esotropia in these patients due to the brainstem dysfunction. The authors would like to emphasize the importance of early diagnosis with MRI and unnecessary ophthalmic surgery.


Journal of Glaucoma | 2015

Comparison of Intraocular Pressure Measurements Between Goldmann Applanation Tonometry and Reichert 7 Noncontact Tonometry.

Sirel Gür Güngör; Ahmet Akman; Ayşe C. Yazici

Purpose:The aim of this study was to compare the Reichert 7 (R7) noncontact tonometry with Goldmann applanation tonometry (GAT) and to determine the influence of central corneal thickness (CCT) in these measurements in the healthy population. Design:A prospective cross-sectional study. Methods:Intraocular pressure (IOP) of the right eyes of 120 patients was measured with GAT and R7. All patients were free of glaucoma. All the measurements were carried out between 7 AM and 9 AM The measurements with the R7 were taken in the automatic mode. After 15 minutes, IOP with GAT was measured followed by pachymetry. The R7 provided a Goldmann-correlated IOP (IOPg) and a corneal-compensated IOP (IOPcc). Results:The mean age of the patients was 53.9±19.3 (range, 26 to 85 y). The male/female ratio was 0.9/1. When R7 measurements were compared with GAT measurements, R7 measurements (both IOPcc and IOPg) were significantly higher than GAT measurements (P⩽0.001). Besides that, IOPcc was significantly higher than IOPg (P⩽0.001). There was a significant positive linear relationship between IOPcc and GAT (r=0.761, P⩽0.001), and similar relationship between IOPg and GAT (r2=0.739, P⩽0.001). The mean CCT was 545.9±33.2 &mgr;m (range, 476 to 634 &mgr;m). A weak correlation was observed between CCT and GAT (r=0.196, P=0.032). There was a significant correlation between CCT and IOPg (r=0.283, P=0.02). The correlation between CCT and IOPcc was not statistically significant (r=0.123, P=0.179). Conclusions:IOP values of R7 are higher than GAT values. However, IOPg was observed more coherent to the GAT values than IOPcc. IOPcc should be an evaluation factor along with GAT or IOPg in glaucoma examination.


Journal of Glaucoma | 2013

Childhood glaucoma as an ophthalmic manifestation of Seckel syndrome.

Zeynep Aktas; Nilay Yuksel; Serdar Kula; Ahmet Akman; Berati Hasanreisoglu

Purpose:The purpose of the study was to report a patient with Seckel syndrome associated with high intraocular pressures despite intensive antiglaucoma treatment. Methods:Case report. Results:High intraocular pressure readings in both eyes measured with the Goldman applanation tonometer, bilateral pigmentary retinopathy and total cupping of optic discs were found. The patient underwent bilateral trabeculectomy surgery as he had medically uncontrolled glaucoma. Conclusions:Childhood glaucoma may be associated with Seckel syndrome.


Ophthalmic Research | 2009

Ciliary Body Toxicity of Subconjunctival Suramin Compared with Mitomycin-C in the Rabbit Eye: Determining the Toxic Concentration

Altuğ Çetinkaya; Ahmet Akman; Gulnur Take; Banu Bilezikçi; Yonca A. Akova

Background/Aims: To evaluate the safety of suramin compared with mitomycin-C (MMC) as an adjunctive agent in trabeculectomy by determining its ciliary body toxicity at predetermined effective dosages in rabbit eyes. Methods: Thirty-two New Zealand albino rabbits received either suramin (200, 300, 400, or 800 mg/ml) or MMC (0.2, 0.3, 0.4, or 0.8 mg/ml) injections subconjunctivally in the right eye. Enucleations were performed on the 1st, 3rd, 7th and 28th day. Untreated left eyes were injected with balanced salt solution and served as controls. The injection-exposed ciliary body specimens were processed to be investigated under the light microscope and transmission electron microscope. Results: There was no pathologic abnormality in specimens under light microscopy. The morphologic evaluation with transmission electron microscopy showed severe changes in structure, except for eyes treated with 200 mg/ml suramin and 0.2 mg/ml of MMC. These changes were more prominent in eyes exposed to MMC, and appeared earlier compared to suramin-treated eyes. Conclusions: Suramin 200 mg/ml and MMC 0.2 mg/ml seem to be comparatively nontoxic to the ciliary body of the rabbit eye. Concentrations higher than these values caused severe damage.


Türk Oftalmoloji Dergisi | 2017

Are All Retinal Nerve Fiber Layer Defects on Optic Coherence Tomography Glaucomatous

Sirel Gür Güngör; Ahmet Akman

Objectives: In this study, we investigated the patients who were referred to our clinic with a prediagnosis of glaucoma based on retinal nerve fiber layer (RNFL) defects on optic coherence tomography (OCT) but were determined to have nonglaucomatous RNLF defects upon detailed examination. Materials and Methods: The ophthalmic examination notes, OCT images, Heidelberg retinal tomography (HRT) II and fundus photographs of 357 patients were retrospectively evaluated. Final diagnoses of these patients were investigated. Results: Of the 357 patients, 216 (60.5%) were diagnosed as open angle glaucoma, 33 (9.2%) as low-tension glaucoma, 39 (10.9%) as pre-perimetric glaucoma. The ophthalmic examinations of 14 patients (3.9%) were normal and there were no RNFL defects in OCT examinations after dilatation. In 39 patients (10.9%), the ophthalmic and optic disc examinations were completely normal and no etiologic factor explaining RNFL defects was found. Twenty-two eyes of 16 patients (4.5%) were included in this study (the mean age was 53.8±11.5 years; 9 men and 7 women). After detailed questioning of the medical history and systemic and neurologic examinations, a diagnosis of ischemic optic neuropathy was made in 11 eyes (10 patients) (2.8%), optic neuritis in 3 eyes (2 patients) (0.6%), optic disc drusen in 4 eyes (2 patients) (0.6%), pseudotumor cerebri in 2 eyes (1 patient) (0.3%), and cerebral palsy in 2 eyes (1 patient) (0.3%). Conclusion: Decrease in RNFL thickness on OCT images alone may be misleading in glaucoma examination. In cases where optic disc cupping is not evident, diagnosis should not be based on OCT RNFL examinations alone, and the patient’s medical history, detailed ophthalmic examination, OCT optic disc parameters, HRT, and visual field tests should all be carefully evaluated together.


Türk Oftalmoloji Dergisi | 2016

Changes in Anterior Chamber Depth after Phacoemulsification in Pseudoexfoliative Eyes and their Effect on Accuracy of Intraocular Lens Power Calculation.

Sirel Gür Güngör; Ahmet Akman; Leyla Asena; Mustafa Aksoy; Almila Sarıgül Sezenöz

Objectives: To compare anterior chamber depth (ACD) changes after phacoemulsification surgery in patients with pseudoexfoliation syndrome (PEX) and normal patients using an anterior segment imaging method. Another aim of this study was to evaluate the effect of these changes on the accuracy of intraocular lens (IOL) power calculation and postoperative refraction. Materials and Methods: Twenty-two eyes of 22 patients with PEX and 30 eyes of 30 normal patients who underwent uneventful phacoemulsification surgery and IOL implantation were included in the study. The ACD of all patients was evaluated preoperatively and at 3 months postoperatively with the ALLEGRO Oculyzer (WaveLight® Oculyzer™ II, Alcon, Novartis)-Scheimpflug imaging system. Results: The postoperative mean ACD values were significantly larger than the preoperative ACD values in both groups (p<0.001 for both groups). The pre- to postoperative change in ACD was 0.46±0.3 mm in the PEX group, which was a larger change than seen in the normal patients (0.12±0.1 mm) (p=0.04). The mean absolute errors (MAE) calculated with different IOL formulas (SRK/T, Haigis, Hoffer and Holladay 1 formulas) were comparable and no statistically significant difference was observed between the two groups (p=0.21). Conclusion: Phacoemulsification induces more significant ACD changes in patients with PEX compared to normal patients. However, the MAE did not differ significantly between the groups.


Türk Oftalmoloji Dergisi | 2017

Corneal, Scleral, Choroidal, and Foveal Thickness in Patients with Rheumatoid Arthritis

Onur Gökmen; Nilufer Yesilirmak; Ahmet Akman; Sirel Gür Güngör; Ahmet Eftal Yücel; Hilmi Yeşil; Fatih Yıldız; Adam Sise; Vasilios F. Diakonis

Objectives: To investigate corneal, scleral, choroidal, and foveal thicknesses in female patients with rheumatoid arthritis (RA) and compare them with healthy subjects. Materials and Methods: This prospective study included consecutive female patients diagnosed with RA and healthy subjects. Corneal, scleral, choroidal, and retinal (foveal) thicknesses were obtained by using optical coherence tomography and a comparison was performed between groups for all outcome measures. Results: Thirty-six eyes of 36 female patients diagnosed with RA (group 1) and 36 eyes of 36 healthy female volunteers (group 2) were included. Mean corneal, scleral, choroidal thicknesses and retinal thickness at the fovea of group 1 were 543.3±33.7 µm, 343.7±42.2 µm, 214.6±50, and 213.5±18.9 µm, respectively; in group 2, these values were 549.9±29.6 μm, 420.9±42.4 μm, 206.4±41.9 μm, and 222±15.5 μm, respectively. The comparison between group 1 and 2 with respect to corneal, choroidal, and foveal thicknesses did not reveal statistical significant differences (p>0.05). On the contrary, there was a statistically significant difference with respect to scleral thickness between the groups, with the RA patients demonstrating a thinner scleral layer (p<0.001). Conclusion: Female patients with RA seem to demonstrate statistically significant scleral thinning when compared with healthy subjects, while there was no difference concerning corneal, choroidal, and foveal thickness.


Türk Oftalmoloji Dergisi | 2017

Early Clinical Features of Pseudoexfoliation Syndrome in Anterior Segment and Gonioscopy Examination

Sirel Gür Güngör; Atilla Bayer; Ahmet Akman; Leyla Asena

Objectives: To determine the early signs of pseudoexfoliation (PEX) in fellow eyes of cases with unilateral PEX. Materials and Methods: Fellow eyes of 34 cases with unilateral PEX were evaluated by slit-lamp and gonioscopy. Findings associated with PEX were recorded. Results: Mean age was 67.8±8.1 years (range 55-86 years). Twenty-five patients (73.5%) had pigmentation in the inferior angle and 23 patients (67.6%) had Sampaolesi’s line located on the inferior angle in fellow eyes. The other most common findings were loss of peripupillary ruff in 10 patients (29.4%) and pigment dispersion following pupil dilation in 14 patients (41.1%). Conclusion: Pigmentation in the inferior angle and Sampaolesi’s line on the inferior angle seem to be the most common early findings associated with PEX. Special attention should be paid to these findings in cases with ocular hypertension for proper management.

Collaboration


Dive into the Ahmet Akman's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge