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Featured researches published by Atilla Bayer.


American Journal of Ophthalmology | 2002

Validity of a new disk grading scale for estimating glaucomatous damage: correlation with visual field damage

Atilla Bayer; Paul Harasymowycz; Jeffrey D. Henderer; William G. Steinmann; George L. Spaeth

PURPOSE To determine the correlation of a new disk grading system, the disk damage likelihood scale (DDLS), with the visual field damage in patients with glaucoma. DESIGN Observational case series. METHODS Charts of 75 patients (150 eyes) with primary open-angle glaucoma (POAG), 41 patients (82 eyes) with low-tension glaucoma (LTG), and 25 patients (50 eyes) with pseudoexfoliative glaucoma (PXFG) were reviewed retrospectively. DDLS stages and vertical disk sizes were recorded. A masked observer staged the Humphrey field analyzer (program 24-2) visual fields using the Hodapp-Parrish-Anderson (HPA) visual field staging system. Mean deviation (MD) and pattern standard deviation (PSD) values were obtained. The correlation of DDLS with the visual field parameters and HPA staging system were evaluated. Findings were assessed by the Pearson and Spearman correlation coefficients. RESULTS In the 282 eyes studied, the DDLS was strongly correlated with both MD (Pearson r = - 0.695, P <.001) and PSD (Pearson r =.703, P <.001). The HPA visual field staging system was also strongly correlated with the DDLS (Spearman r =.711, P <.001). These relationships continued to be significant when the three diagnostic groups (POAG, LTG, PXFG) were evaluated separately (P <.001) and also for small (< 1.5 mm) and average size (1.5-2.0 mm) disks. Large disks (> 2.0 mm) were not evaluated, because there was an insufficient number of cases. CONCLUSION DDLS, a new system for estimating glaucomatous disk damage, strongly correlates with the degree of glaucomatous visual field damage.


Ophthalmology | 2010

Safety and Effectiveness of Interferon Alpha-2a in Treatment of Patients with Behçet's Uveitis Refractory to Conventional Treatments

Gungor Sobaci; Uzeyir Erdem; A.Hakan Durukan; Cuneyt Erdurman; Atilla Bayer; Serkan Köksal; Suat Karagül; M.Zeki Bayraktar

PURPOSE To evaluate the intermediate-term safety and effectiveness of interferon alpha-2a (IFNalpha2a) in patients with Behçets uveitis (BU) refractory to corticosteroids and immunosuppressive agents. DESIGN Open, nonrandomized, uncontrolled, interventional, prospective study. PARTICIPANTS Fifty-three patients (106 eyes) with active, vision-threatening BU who failed to respond to conventional treatments. INTERVENTION In 53 patients, acute inflammation was suppressed with effective prednisolone dosage (1-2 mg/kg/day, tapered to 10 mg within 4-6 weeks). The patients were treated with IFNalpha2a 4.5 million international units (MIU) 3 times per week for the first 3 months followed by IFNalpha2a 3 MIU 3 times per week for the next 3 months. Observation or other treatment methods were performed according to the decision tree developed for this study. MAIN OUTCOME MEASURES Remission and complete response (primary outcome measures), frequency of uveitis attacks, visual acuity (VA), and adverse effects (secondary outcome measures). RESULTS During 2 years of follow-up (median 65 months, range 12-130 months), compliance with the therapy was excellent. At the end of 1-year follow-up, treatment response was obtained in 45 of 53 patients (84.9%). The mean attack rate of 3.6+/-1.1 per year (range, 2-8) decreased to 0.56+/-0.75 (range, 0-4) per year (P=0.001). Visual acuity improved (> or = 0.2 logarithm of the minimum angle of resolution units from initial VA) in 30 eyes (28.3%) and worsened in 12 eyes (11.3%). Five patients (9.4%) did not respond to the initial treatment, and 3 patients (5.6%) developed severe adverse effects, including psoriasis, epileptic seizure, and extreme tiredness. Fifteen patients (28.3%) were off treatment for all the medications and disease free for 28+/-13.1 months (range, 12-50 months). CONCLUSIONS These results suggest that IFNalpha2a may be a valuable treatment option in BU that is refractory to corticosteroids and conventional immunosuppressive agents. The possible role of IFNalpha2a as a first-line agent in BU should be validated in randomized controlled clinical trials against newly described biologic agents. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.


American Journal of Ophthalmology | 2003

Reliability of the disk damage likelihood scale

Jeffrey D. Henderer; Connie Liu; Muge Kesen; Undraa Altangerel; Atilla Bayer; William C. Steinmann; George L. Spaeth

PURPOSE To report the reliability of the glaucoma disk damage likelihood scale (DDLS) in comparison to the Armaly cup/disk ratio by determining the interobserver and intraobserver agreement for optic disk stereo photographs and the interobserver agreement for in vivo patient measurements of the optic disk. DESIGN Observational case series. METHODS Optic disk photographs: 48 stereo pairs of optic nerve photographs were selected from patients with a spectrum of glaucomatous visual field loss. Two masked observers graded the optic disk photographs three times according to the DDLS and Armaly cup/disk ratio. Interobserver and intraobserver agreements were calculated using the test-retest method. Patient measurements: three observers performed in vivo patient measurements on 34 eyes of glaucoma clinic patients and made a single determination of the DDLS stage and Armaly cup/disk ratio, based on the indirect biomicroscopic examination. Level of interobserver agreement was tabulated. RESULTS Optic disk photographs: interobserver and intraobserver agreement for the vertical DDLS measurement was greater than for two determinations (clinical impression and measured) of the vertical Armaly cup/disk ratio (interobserver: 85% vs 68% and 74%, respectively; intraobserver grader 1: 97% vs 89% and 80%, grader 2: 99% vs 95% and 89%, respectively). In vivo patient measurements: the interobserver agreement for the DDLS and Armaly cup/disk ratio was similar (70.1% vs 67.6%, respectively). CONCLUSIONS For the stereo optic disk photographs, the inter- and intra-observer agreement for the DDLS is greater than the Armaly cup/disk ratio. For the in vivo patient measurements, the level of agreement for the DDLS and the Armaly cup/disk ratio is similar.


Journal of Glaucoma | 2007

Laser suture lysis or releasable sutures after trabeculectomy.

Aykan U; Ahmet Hamdi Bilge; Tugrul Akin; Ismail Certel; Atilla Bayer

PurposeTo compare the efficacy and complication rates of laser suture lysis (LSL) or releasable sutures techniques after trabeculectomy. Materials and MethodsForty-eight eyes of 43 consecutive patients with uncomplicated glaucoma who were recruited for primary trabeculectomy with mitomycin-C were divided into 2 groups. Group 1 and group 2 comprised 27 and 21 eyes that were randomly assigned to a standard surgery and releasable suture groups, respectively. A target intraocular pressure (IOP) had been determined on the basis of the severity of the glaucoma and was called a complete success, qualified success, or failure. ResultsIn group 1, the mean change in IOP after LSL was 7.31±1.98 mm Hg, 6.1±1.1 mm Hg, and 3.9±1.5 mm Hg when sutures were lysed on the first, second, and third months. In group 2, the mean change in IOP after releasable suture removed was 8.20±2.74 mm Hg, 5.12±1.65 mm Hg, and 4.4±1.0 mm Hg when sutures were released at the first, second, and third months. At the end of 6 months, the success (complete and qualified success) rates were 92% and 90% for LSL and releasable suture groups, respectively. There was no statistically significant differences in success (P>0.05) and complication (P>0.05) rates between groups. ConclusionsWe observed an effective IOP reduction in eyes that had suture release both in the early and late postoperative periods after LSL and suture release. We believe that both the laserable and releasable suture techniques can be preferred to permanent sutures for closing scleral flaps in primary trabeculectomy with mitomycin-C in uncomplicated glaucoma.


Journal of Glaucoma | 2010

Intraocular pressure values obtained by ocular response analyzer, dynamic contour tonometry, and goldmann tonometry in keratokonic corneas.

Atilla Bayer; Afsun Sahin; Volkan Hurmeric; Gokhan Ozge

PurposeTo determine the agreement between dynamic contour tonometer (DCT), Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA) in keratoconic corneas and to find out the effect of corneal biomechanics on intraocular pressure (IOP) measurements obtained by these devices. Subjects and MethodsIOP was measured with the ORA, DCT, and GAT in random order in 120 eyes of 61 keratoconus patients. Central corneal thickness (CCT) and keratometry were measured after all IOP determinations had been made. The mean IOP measurement by the ORA and DCT was compared with the measurement by the GAT, using Student t test. Bland-Altman analysis was performed to assess the clinical agreement between these methods. The effect of corneal hysteresis (CH), corneal resistance factor (CRF), and CCT on measured IOP was explored by multiple backward stepwise linear regression analysis. ResultsThe mean±SD patient age was 30.6±11.2 years. The mean±SD IOP measurement obtained with GAT, ORA Goldmann-correlated IOP (IOPg), ORA corneal-compensated IOP (IOPcc), and DCT was 10.96±2.8, 10.23±3.5, 14.65±2.8, and 15.42±2.7 mm Hg, respectively. The mean±SD CCT was 464.08±58.4 microns. The mean difference between IOPcc and GAT (P<0.0001), IOPcc and DCT (P<0.001), GAT and DCT (P<0.0001), IOPg and GAT (P<0.002), and IOPg and DCT (P<0.0001), was highly statistically significant. In multivariable regression analysis, DCT IOP and GAT IOP measurements were significantly associated with CH and CRF (P<0.0001 for both). ConclusionsDCT seemed to be affected by CH and CRF, and the IOP values tended to be higher when compared with GAT. ORA-measured IOPcc was found to be independent of CCT and suitable in comparison to the DCT in keratoconic eyes.


Journal of Glaucoma | 2005

Clinical predictors of latanoprost treatment effect.

Atilla Bayer; Jeffrey D. Henderer; Terry Kwak; Jonathan S. Myers; J. Fontanarosa; George L. Spaeth

Purpose:To determine the relationship between latanoprost efficacy and clinical features of glaucoma. Patients and Methods:Study design was retrospective, observational case series. The charts of all patients who underwent a one-eyed therapeutic trial of latanoprost during the course of their clinical care between 1997 and 2001 were reviewed. Intraocular pressures of both eyes prior to and one month after initiation of latanoprost were recorded. Latanoprost treatment effect was calculated by subtracting the change in intraocular pressure (IOP) in the fellow eye from the change in the treated eye. The effect of optic disc stage, age, race, sex, diagnosis, involved eye, type and number of other glaucoma medications, pattern of cupping (concentric, focal, or indeterminate), and pre-treatment IOP was correlated with the treatment effect. The stage of glaucoma was determined by determining the disc damage likelihood scale (DDLS) stage. Results:One hundred eighty-six cases were included. Latanoprost treatment effect was 4.5 ± 5.7 mm Hg, was moderately correlated with pre-treatment IOP (Pearsons r = 0.527, P < 0.01), and was weakly inversely correlated with advancing disc stage (Pearsons r = −0.194, P < 0.01) and age (Pearsons r = −0.175, P < 0.05). It was independent of the other variables studied (P > 0.05). Conclusion:Most clinical parameters examined in this study were not correlated with latanoprost treatment response. A moderate direct correlation was noted with pre-treatment IOP and a weak inverse correlation was noted with optic disc stage and age.


European Journal of Ophthalmology | 2009

Evaluating a new disc staging scale for glaucomatous damage: the ability to detect change over time.

Jeffrey D. Henderer; Yun Wang; Atilla Bayer; Undraa Altangerel; Louis W. Schwartz; Courtland M. Schmidt

Purpose To assess the ability of Disc Damage Likelihood Scale (DDLS) in detecting glaucomatous changes in the optic nerve on sequential optic disc stereo-photographs as compared with three other different cup/disc grading systems (C/D). Methods Eighty-three pairs of stereo-photographs with a minimum of 5-year follow-up were examined by one group of three observers masked to chronological order by using their clinical expertise. Their conclusions were considered gold standard. Another group of three glaucoma experts examined the same masked pairs to evaluate glaucomatous changes using four different optic nerve grading systems: DDLS, vertical, horizontal, and maximal cup/disc. Ratings of these four methods in the second group were then compared with the gold standard. Results Baseline and follow-up photographs of 83 eyes were included. Mean follow-up was 6 years. The sensitivities for detecting glaucomatous nerve changes were 71.4%, 63.9%, 66.7%, and 47.2% for DDLS, vertical, horizontal, and maximal cup/disc, respectively. The specificity for finding nerve change was 70.9%, 51.1%, 40.4%, and 48.9%, respectively. The proportion of photographs identified as showing glaucomatous changes differed significantly between the DDLS and vertical C/D (VCD) (χ2=7.900, p=0.005), between the DDLS and horizontal C/D (HCD) (χ2=13.89, p=0.000), and between DDLS and maximum C/D (MCD) (χ2=4.192, p=0.041). The largest area (74.4%) under the receiver operator characteristic curve was obtained by using the DDLS. Conclusions DDLS had higher sensitivity and specificity for detecting glaucomatous changes versus the other three C/Ds when considering sequential stereo-photographs.


Journal of Trauma-injury Infection and Critical Care | 2010

An unusual case of glaucoma: traumatic glaucoma probably caused by shock waves.

Atilla Bayer; Tarkan Mumcuoglu; Gokhan Ozge; Ali İhsan Uzar

Ocular traumas often result in multiple structural alterations within the eye.1 High velocity blunt objects such as balls, stones, or airbags often cause direct trauma to the eye. The damage from the impact of a blunt object is mediated through structural injury associated with rapid compression of the ocular tissue resulting in rapid elongation along the equatorial plane.1 Penetrating ocular injuries, on the other hand, have different mechanisms of action and are commonly combined with injuries of various ocular tissues such as cornea, sclera, iris, lens, vitreous, retina, and choroid. Damage or obstruction of the trabecular meshwork by the effect of these injuries can lead to the development of posttraumatic glaucoma.2 We report an unusual case in which posttraumatic glaucoma has developed after injury to the eyebrow area with a gunshot. This case had a glaucoma that might have an unusual mechanism of development.


Transactions of the American Ophthalmological Society | 2002

The disc damage likelihood scale: reproducibility of a new method of estimating the amount of optic nerve damage caused by glaucoma.

George L. Spaeth; Jeffrey D. Henderer; Connie Liu; Muge Kesen; Undraa Altangerel; Atilla Bayer; L. Jay Katz; Jonathan S. Myers; D.J. Rhee; William C. Steinmann


Journal of Refractive Surgery | 2008

Pupil center shift relative to the coaxially sighted corneal light reflex under natural and pharmacologically dilated conditions.

Uzeyir Erdem; Orkun Muftuoglu; Fatih C. Gundogan; Gungor Sobaci; Atilla Bayer

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Gungor Sobaci

Military Medical Academy

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Cem Ozgonul

University of Michigan

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Gokhan Ozge

Military Medical Academy

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Suat Karagül

Military Medical Academy

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