Network


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

Hotspot


Dive into the research topics where Ömer Yilmaz is active.

Publication


Featured researches published by Ömer Yilmaz.


Journal of Cataract and Refractive Surgery | 2008

Intracorneal inlay for the surgical correction of presbyopia

Ömer Yilmaz; Sukru Bayraktar; Alper Agca; Basak Yilmaz; Marguerite B. McDonald; Corina van de Pol

PURPOSE: To evaluate the clinical safety and efficacy of the ACI‐7000 intracorneal inlay in increasing the depth of field in emmetropic presbyopic patients. SETTING: Beyoglu Eye Research and Education Hospital, Istanbul, Turkey. METHODS: This prospective unmasked study comprised 39 presbyopic patients; 12 were naturally emmetropic and 27 had emmetropia resulting from previous hyperopic laser in situ keratomileusis. The intracorneal inlay was placed over the pupil in the patients nondominant eye after flap lift or creation of a conventional flap using a microkeratome. The inlay was centered on the visual axis. Postoperative follow‐up was 1 year. RESULTS: Of the 39 inlays implanted, 3 were explanted during the study. At 1 year, the mean uncorrected near visual acuity improved from J6 (preoperatively) to J1+. All eyes with an inlay had an uncorrected near acuity of J3 or better and 85.3%, of J1 or better. Binocularly, the mean uncorrected near acuity remained J1 or better throughout the study. The mean uncorrected distance visual acuity in eyes with an inlay did not change significantly from preoperatively and remained 20/20 throughout the study period. All 3 eyes with inlay explantation returned to within ±1.00 diopter of the preoperative refractive state for near and distance vision, with no loss of best corrected distance visual acuity. CONCLUSION: The ACI‐7000 intracorneal inlay showed the potential to provide safe, effective, and reversible treatment of presbyopia.


Current Eye Research | 2007

Evaluation of Macular Changes After Uncomplicated Phacoemulsification Surgery by Optical Coherence Tomography

Irfan Perente; Canan Asli Utine; Can Öztürker; Mehmet Çakır; Vedat Kaya; Hakan Eren; Ziya Kapran; Ömer Yilmaz

Purpose: To evaluate the effect of uncomplicated phacoemulsification surgery on macula by optical coherence tomography (OCT). Methods: A total of 110 eyes of 102 patients who underwent uncomplicated phacoemulsification and foldable intraocular lens implantation at Beyoglu Eye Research and Training Hospital between February and March 2005 and who were without any systemic disease, fundus or other ocular pathology were included. Postoperatively, topical prednisolone acetate (6× 1) and ofloxacine (5× 1) was started, and by decreasing the dosage progressively, treatment was continued for 6 weeks. Full ophthalmologic and OCT examinations were done preoperatively and at the postoperative 1st day, 1st week, 1st, 3rd, and 6th months. Mean retinal thicknesses, volumetric analyses at central fovea, superior, inferior, temporal, and nasal macular quadrants, and thinnest foveal retinal thicknesses were recorded. Preoperative and postoperative measurements were analyzed statistically by using ANOVA test, paired samples t-test with Bonferroni correction, and Pearsons correlation test. Results: The mean central foveal retinal thickness was preoperatively 202.4 ± 25.9 μ m, postoperatively 200.4 ± 26.1 μ m at 1st day (p = 0.29), 208.4 ± 27.6 μ m at 1st week (p = 0.29), 226.2 ± 54.9 μ m at 1st month, 215.2 ± 24.0 μ m at 3rd month, 213.5 ± 29.4 μ m at 6th month (p < 0.001). Perifoveal macular thicknesses at superior, inferior, temporal, and nasal quadrants were 264.9 ± 28.8 μ m, 266.1 ± 29.5 μ m, 255.0 ± 31.3 μ m, 260.3 ± 34.0 μ m, respectively, preoperatively; 287.9 ± 28.4 μ m, 288.0 ± 26.3 μ m, 286.8 ± 33.1 μ m, 272.0 ± 32.4 μ m, respectively, at postoperative 1st month (p < 0.001). The change in mean central foveal thickness, foveal thinnest retinal thickness, mean perifoveal retinal thickness and volumetric analyses was insignificant at postoperative 1st day (p > 0.05), and significant at 1st week, 1st, 3rd, and 6th months (p < 0.05 for all measurements). Conclusions: Statistically significant increase in macular thickness was detected at postoperative early periods, after the 1st week after uncomplicated cataract operation. The increase in macular thickness starts from parafoveal regions. Longer follow-up of patients is required for the macular consequences, and different treatment protocols should be studied in a randomized controlled fashion.


Journal of Cataract and Refractive Surgery | 2011

Intracorneal inlay to correct presbyopia: Long-term results

Ömer Yilmaz; Neşe Alagöz; Gökhan Pekel; Engin Azman; Ebru Funda Aksoy; Hanefi Cakir; Ercument Bozkurt; Ahmet Demirok

PURPOSE: To evaluate the long‐term visual results of Acufocus ACI‐7000 (now Kamra) intracorneal inlay implantation in presbyopic phakic patients. SETTING: Beyoğlu Eye Training and Research Hospital, Istanbul, Turkey. DESIGN: Clinical trial. METHODS: This study comprised patients with emmetropic or post‐laser in situ keratomileusis (LASIK) presbyopia. Patients had an uncorrected near visual acuity (UNVA) of 20/40 or worse, correctable to 20/25 or better at distance. The inlay was implanted on the stromal bed after the LASIK flap was relifted or a flap created. The inlay was centered on the presurgical position of the first Purkinje reflex. The main outcome measures were distance and near vision and the complication rate. RESULTS: The study enrolled 39 patients aged 45 to 60 years. At the 4‐year follow‐up, all patients (N = 22) had 2 or more lines of improvement in UNVA with no significant loss in distance vision. The mean final UNVA was 20/20 (Jaeger [J1]); 96% of patients could read J3 or better. The uncorrected distance acuity was 20/40 or better in all eyes. Five patients had cataract progression, and 2 had a change in refractive status. No eye with an intracorneal inlay had intraoperative complications during cataract extraction. Four inlays were explanted during the study. There were no severe corneal complications that affected final vision. CONCLUSION: Intracorneal inlay implantation was an effective, safe, and reversible procedure for the long‐term surgical treatment of presbyopia. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.


Journal of Cataract and Refractive Surgery | 1998

Effect of superior and temporal clear corneal incisions on astigmatism after sutureless phacoemulsification

Şaban Şİmşek; Tekin Yasar; Ahmet Demirok; Adnan Çinal; Ömer Yilmaz

Purpose: To evaluate the effect of superior and temporal clear corneal incisions on astigmatism after sutureless, small incision phacoemulsification. Setting: World Eye Hospital, Istanbul, Turkey. Methods: This prospective study evaluated 40 eyes of 20 patients with cataract having bilateral, sutureless, small incision phacoemulsification by the same surgeon. A superior clear corneal incision was used in all right eyes and a temporal clear corneal incision in all left eyes. Mean preoperative astigmatism was 0.63 diopter (D) ± 0.21 (SD) and 0.65 ± 0.20 D, respectively. Mean patient age was 66.45 years. Patients were examined preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively. Results: Three months postoperatively, mean astigmatism was 1.60 ± 0.37 D in the superior incision group and 0.83 ± 0.19 D in the temporal incision group. Induced astigmatism calculated by vector analysis was 1.44 ± 0.31 D and 0.62 ± 0.28 D, respectively. The temporal incision group had significantly lower astigmatism at all follow‐ups (P = .000). Conclusion: Upper lid pressure on the superior corneal incisions led to fluctuating, against‐the‐rule astigmatism that was significantly higher than that induced by temporal incisions.


Journal of Cataract and Refractive Surgery | 2012

Accelerated corneal crosslinking concurrent with laser in situ keratomileusis.

H. Ugur Celik; Neşe Alagöz; Yusuf Yildirim; Alper Agca; John Marshall; Ahmet Demirok; Ömer Yilmaz

PURPOSE: To assess accelerated corneal collagen crosslinking (CXL) applied concurrently with laser in situ keratomileusis (LASIK) in a small group of patients. SETTING: Beyoglu Eye Research and Training Hospital, Istanbul, Turkey. DESIGN: Prospective pilot interventional case series. METHODS: In May 2010, patients had LASIK with concurrent accelerated CXL in 1 eye and LASIK only in the fellow eye to treat myopia or myopic astigmatism. The follow‐up was 12 months. The attempted correction (spherical equivalent) ranged from −5.00 to −8.50 diopters (D) in the LASIK–CXL group and from −3.00 to −7.25 D in the LASIK‐only group. Main outcome measures were manifest refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, and the endothelial cell count. RESULTS: Eight eyes of 3 women and 1 man (age 22 to 39 years old) were enrolled. At the 12‐month follow‐up, the LASIK–CXL group had a UDVA and manifest refraction equal to or better than those in the LASIK‐only group. No eye lost 1 or more lines of CDVA at the final visit. The endothelial cell loss in the LASIK–CXL eye was not greater than in the fellow eye. No side effects were associated with either procedure. CONCLUSIONS: Laser in situ keratomileusis with accelerated CXL appears to be a promising modality for future applications to prevent corneal ectasia after LASIK treatment. The results in this pilot series suggest that evaluation of a larger study cohort is warranted. Financial Disclosure: Drs. Yilmaz and Marshall are paid consultants to Avedro, Inc. No other author has a financial or proprietary interest in any material or method mentioned.


Journal of Cataract and Refractive Surgery | 2001

Capsular tension ring implantation after capsulorhexis in phacoemulsification of cataracts associated with pseudoexfoliation syndrome intraoperative complications and early postoperative findings

Şükrü Bayraktar; Tugrul Altan; Yaşar Küçüksümer; Ömer Yilmaz

Purpose: To evaluate the effect of an endocapsular tension ring in preventing zonular complications during phacoemulsification of cataracts associated with pseudoexfoliation syndrome. Setting: Eye Clinic of Beyoğlu Education and Research Hospital, Istanbul, Turkey. Methods: A prospective randomized study comprised 78 eyes with cataract and pseudoexfoliation syndrome that were randomly divided into 2 groups. The age, sex, cataract density, iridodonesis, axial length, anterior chamber depth, best corrected visual acuity (BCVA), and intraocular pressure (IOP) were matched between groups. In 39 eyes, a capsular tension ring (CTR) was implanted after capsulorhexis and hydrodissection but before nucleus emulsification. Thirty‐nine eyes that did not have a CTR implanted served as a control. The main outcome measures were the rates of intraoperative zonular separation and capsular fixation of a foldable intraocular lens (IOL). Posterior capsule rupture without zonular dialysis, vitreous loss, corneal edema, fibrin in the anterior chamber, BCVA, and IOP in the immediate postoperative period were also compared between the 2 groups. Results: Five eyes (12.8%) in the control group and no eye in the CTR group had intraoperative zonular separation (P = .02). Posterior capsule rupture without zonular separation occurred in 3 eyes (7.7%) in the control group and 2 (5.2%) in the CTR group. Capsular IOL fixation was achieved in 37 eyes (94.9%) in the CTR group and 31 eyes (74.3%) in the control group (P = .012). The difference in BCVA was not statistically significant between the 2 groups (P = .44); however, uncorrected visual acuity (UCVA) was significantly better in the CTR group (P = .026). Conclusion: In cases of cataract associated with pseudoexfoliation syndrome, implanting a CTR before phacoemulsification of the nucleus reduced intraoperative zonular separation, increased the rate of capsular IOL fixation, and improved UCVA.


Contact Lens and Anterior Eye | 2014

Comparison of corneal hysteresis and corneal resistance factor after small incision lenticule extraction and femtosecond laser-assisted LASIK: A prospective fellow eye study

Alper Agca; Engin Bilge Ozgurhan; Ahmet Demirok; Ercument Bozkurt; Ugur Celik; Abdullah Ozkaya; Ilker Cankaya; Ömer Yilmaz

PURPOSE To compare corneal hysteresis (CH) and corneal resistance factor (CRF) between eyes treated with small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (femto-LASIK). SETTING Beyoğlu Eye Training and Research Hospital. DESIGN Prospective comparative case series. METHODS Sixty eyes from 30 patients with bilateral myopia or myopic astigmatism were studied. Inclusion criteria were spherical equivalent of subjective manifest refraction (SE) <10diopters (D) and a difference ≤0.50D between the SEs of both eyes. One eye of each patient was treated with SMILE, and the fellow eye underwent femto-LASIK. Randomization was performed using a sealed envelope system. The main outcome measures were CH and CRF measured preoperatively and postoperatively (1 and 6 months). RESULTS Preoperative SE was similar in both groups (p=0.852). CH and CRF values were reduced postoperatively in both groups compared to their corresponding preoperative values (p<0.001). At the 6-month follow-up visit, the mean CH values in the SMILE and femto-LASIK groups were 8.95±1.47 and 9.02±1.27, respectively (p=0.852), and the mean CRF values were 7.77±1.37 and 8.07±1.26, respectively (p=0.380). CONCLUSION CH and CRF decreased after SMILE. There were no differences between SMILE and femto-LASIK treatments in postoperative CH or CRF values.


Journal of Refractive Surgery | 2010

Central corneal thickness, anterior chamber depth, and pupil diameter measurements using Visante OCT, Orbscan, and Pentacam.

Ahmet Taylan Yazici; Ercument Bozkurt; Cengiz Alagöz; Neşe Alagöz; Gökhan Pekel; Vedat Kaya; Ömer Yilmaz

PURPOSE To evaluate the agreement among three different optical methods in measuring anterior chamber depth (ACD), central corneal thickness (CCT), and pupil diameter. METHODS One hundred eyes of 50 healthy patients (25 men, 25 women) were enrolled in the study. Mean patient age was 25 years (range: 21 to 32 years). Exclusion criteria were history of any intraocular or corneal surgery, contact lens wear, corneal anomalies, and spherical refraction >5.00 diopters (D) or cylindrical refraction >2.00 D. All measurements were done by the same operator under mesopic light conditions and repeated using three different optical methods: Visante optical coherence tomography (OCT) (Carl Zeiss Meditec), Orbscan (Bausch & Lomb), and Pentacam (Oculus Optikgeräte GmbH). RESULTS Mean CCT as measured by Visante OCT, Orbscan, and Pentacam was 529+/-30.5 microm, 554+/-32.7 microm, and 552+/-29.3 microm, respectively. Mean ACD values were 2.94+/-0.34 mm, 2.84+/-0.33 mm, and 2.98+/-0.33 mm, respectively. Mean pupil diameter measurements were 4.87+/-1.09 mm, 4.0+/-0.67 mm, and 3.05+/-0.59 mm, respectively. The Visante OCT measured CCT thinner and Orbscan measured ACD shallower than the other two methods. All three methods measured pupil diameters significantly different. CONCLUSIONS This study found some statistically significant but clinically insignificant differences among the optical methods assessed. The differences are small and do not influence decisions for refractive surgery in clinical practice.


Journal of Cataract and Refractive Surgery | 2000

Posterior capsule opacification 3 years after implantation of an AcrySof and a MemoryLens in fellow eyes

Yaşar Küçüksümer; Şükrü Bayraktar; Şükran Şahin; Ömer Yilmaz

PURPOSE To compare the rates of lens epithelial cell (LEC) migration and posterior capsule opacification (PCO) 1 and 3 years after sutureless small incision phacoemulsification and in-the-bag implantation of 2 acrylic polymer intraocular lenses (IOLs)-the AcrySof and MemoryLens-in fellow eyes of patients. SETTING Eye Clinic, Beyoğlu Education and Research Hospital, Istanbul, Turkey. METHODS Fifty patients with no systemic or ocular problems that would interfere with postoperative visual acuity were included in this prospective study. Each patient had in-the-bag implantation of an AcrySof IOL in 1 eye and a MemoryLens in the fellow eye in a randomized fashion after uneventful phacoemulsification through a sutureless clear corneal incision. RESULTS At 1 year (n = 32 patients), there was no significant difference between fellow eyes in postoperative best corrected visual acuity (BCVA) and contrast sensitivity. In the MemoryLens group, 10 eyes (31.3%) had PCO and 9 (28.1%), LEC migration. In the AcrySof group, no eye had PCO and 2 eyes (6.3%) had LEC migration (P <.001). At 3 years (n = 21 patients), 1 eye (4.7%) in the AcrySof group had PCO and 3 eyes (14.4%) had LEC migration without PCO. In the MemoryLens group, 1 eye (4.7%) had a clear posterior capsule, 11 eyes (52.4%) had LEC migration, and 9 eyes (42.9%) had PCO (P <.001). A neodymium:YAG capsulotomy was required in 4 eyes (19.0%) in the MemoryLens group but no eye in the AcrySof group. At 3 years, BCVA was lower in the MemoryLens group than in the AcrySof group (P <.05). CONCLUSION The 3 year clinical data of fellow eyes indicate that the AcrySof IOL causes less PCO than the MemoryLens.


Contact Lens and Anterior Eye | 2014

Comparison of visual acuity and higher-order aberrations after femtosecond lenticule extraction and small-incision lenticule extraction.

Alper Agca; Ahmet Demirok; Kadir Ilker Cankaya; Dilek Yaşa; Ali Demircan; Yusuf Yildirim; Abdullah Ozkaya; Ömer Yilmaz

PURPOSE To compare postoperative visual acuity and higher-order aberrations (HOAs) after femtosecond lenticule extraction (FLEX) and after small-incision lenticule extraction (SMILE). METHODS Medical records of refractive lenticule extraction patients were retrospectively reviewed. Twenty patients were treated with FLEX. A comparable group of 20 SMILE patients were retrospectively identified. Only one eye of each patient was randomly chosen for the study. Visual acuity, subjective manifest refraction and corneal topography before and 6 months after the surgery were analyzed for both groups. Total HOAs, spherical aberrations, coma and trefoil were calculated from topography data over the 4- and 6-mm-diameter central corneal zone. RESULTS The mean preoperative SE was -4.03 ± 1.61 in the SMILE group and -4.46 ± 1.61 in the FLEX group. One year after surgery, the mean SE was -0.33 ± 0.25 in the SMILE group and -0.31 ± 0.41 in the FLEX group (p=0.86). In the SMILE group a greater number of eyes were within ±0.50D of the target refraction (95% versus 75%); however, the difference was not statistically significant (p=0.18). Furthermore, 80% of FLEX eyes and 95% of SMILE eyes had an uncorrected distance visual acuity of 20/25 or better (p=0.34). Total HOAs, spherical aberration, coma and trefoil increased postoperatively in both groups. However, there was no statistically significant difference between the groups preoperatively and postoperatively. CONCLUSION FLEX and SMILE result in comparable refractive results. In addition, corneal aberrations induced by different techniques of lenticule extraction seemed similar to each other.

Collaboration


Dive into the Ömer Yilmaz's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ahmet Demirok

Yüzüncü Yıl University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Necip Kara

University of Gaziantep

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge