Guenal Kahraman
Medical University of Vienna
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Publication
Featured researches published by Guenal Kahraman.
Journal of Cataract and Refractive Surgery | 2007
Sibylla Richter-Mueksch; Guenal Kahraman; M. Amon; Gebtraud Schild-Burggasser; J. Schauersberger; Claudette Abela-Formanek
PURPOSE: To evaluate the uveal and capsular biocompatibility of 3 types of sharp‐edged foldable intraocular lenses (IOLs) in eyes with pseudoexfoliation syndrome (PEX). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Eighty‐five eyes with PEX had implantation of 1 of the following sharp‐edged 3‐piece IOLs: hydrophilic acrylic (Injectacryl F3000, OphthalMed), hydrophobic acrylic (AcrySof MA60MB, Alcon), or silicone (CeeOn 911, AMO). Postoperative evaluation (flare, cellular reaction, and capsular reaction) was performed at 1, 3, and 7 days as well as 1, 3, 6, and 12 to 18 months. RESULTS: One year after surgery, flare was comparable between the IOLs. In terms of uveal biocompatibility, whereas the Injectacryl had the highest deposition of debris on the IOL surface (P = .04), the CeeOn 911 had significantly more small round cells in the first 6 months (P<.03). The AcrySof had the highest number of foreign‐body giant cells (P = .01). In terms of capsular biocompatibility, lens epithelial cell outgrowth was highest in the AcrySof group (P<.02). Anterior capsule opacification was comparable between the 3 groups. Posterior capsule opacification was mild in all groups but was significantly greater in the Injectacryl group (P<.05). There were no cases of clinically significant IOL decentration or capsule contraction. CONCLUSIONS: In general, inflammatory cells accumulated more easily on hydrophobic IOLs than on hydrophilic IOLs; the AcrySof IOL had the highest prevalence of foreign‐body giant cells. All 3 IOLs had good biocompatibility, although the AcrySof group had increased inflammatory signs.
Journal of Cataract and Refractive Surgery | 2011
Claudette Abela-Formanek; M. Amon; Guenal Kahraman; Joerg Schauersberger; Roman Dunavoelgyi
PURPOSE: To evaluate the long‐term uveal and capsular biocompatibility of 5 intraocular lenses (IOLs) in eyes with uveitic cataract. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. DESIGN: Comparative case series. METHODS: Patients with uveitis of various origin were consecutively recruited for cataract surgery (1998–2006) and received 1 of 3 hydrophilic acrylic IOLs (Hydroview, AcrySof MA60BM, or Injectacryl F3000), a silicone IOL (CeeOn 911), or a hydrophilic acrylic IOL with heparin surface modification (BioVue3). A 7‐year follow‐up was performed in the Hydroview, AcrySof, and CeeOn groups. Visual acuity, anterior chamber flare measurements, specular microscopy, biomicroscopy, and fundoscopy were performed postoperatively at 6 months and 1, 2, and 3 years. RESULTS: The study enrolled 136 eyes of 115 patients. There were no significant differences in anterior chamber flare results between the 5 groups. The Hydroview group had the highest grade and the CeeOn IOL and AcrySof groups had the lowest grade of posterior capsule opacification. The BioVue3 and Injectacryl IOLs had good uveal biocompatibility. Patients in all groups had better visual acuity postoperatively. CONCLUSIONS: Overall, patients with uveitis benefited from cataract surgery. The long‐term results indicate that all sharp‐edged hydrophilic and hydrophobic IOLs performed well in eyes with uveitis. Higher uveal biocompatibility was achieved with the modern hydrophilic acrylic IOLs than with the hydrophobic acrylic IOL. Modern hydrophilic acrylic IOLs seem to be a good option in these cases. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.
Acta Ophthalmologica | 2011
G. Stock; C. Ahlers; Roman Dunavoelgyi; Guenal Kahraman; Joerg Schauersberger; Ursula Schmidt-Erfurth; M. Amon
Purpose: To investigate the physiological retinal response to uneventful cataract surgery using conventional time‐domain (TD‐OCT) and current spectral‐domain optical coherence tomography (SD‐OCT) in combination with an assessment of the anterior chamber inflammatory reaction by laser flare/cell meter (LCFM).
British Journal of Ophthalmology | 2014
Guenal Kahraman; Harald Schrittwieser; Michael Walch; Frank Storch; Karl Nigl; Clara Ferdinaro; Michael Amon
Purpose To evaluate and compare the 1-year postoperative levels of posterior capsule opacification (PCO) as well as the level of anterior capsule retraction and opacification (ACO) after implantation of two single-piece hydrophobic acrylic intraocular lens (IOL) models. Methods Randomised, controlled, prospective and double-blind study including 148 eyes of 74 patients (age range, 61–80 years) with bilateral senile cataract. Each patient underwent surgery with implantation of an AcrySof SA60AT (Group A) in one eye and Tecnis ZCB00 (Group B) in the fellow eye by the same experienced surgeon. Lens allocation to the first or second operated eye followed a randomisation process. At 12 months postoperatively, the PCO level was evaluated with the Evaluation of Posterior Capsule Opacification software, whereas the level of ACO and capsule retraction was evaluated and graded subjectively. Results All surgeries were uneventful. The mean PCO scores were 0.10±0.17 and 0.21±0.89 in Groups A and B, respectively, with no statistically significant differences between the groups (p=0.47). No significant correlation was found between the PCO scores in Groups A and B (r=0.16, p=0.17). Regarding ACO, it was present in 15 eyes (20.3%) and two eyes (2.7%) in Groups A and B, respectively (p=0.37). Capsular phimosis (13 eyes, 17.6%) was only observed in Group A. Conclusions Both IOLs had a similar low rate of PCO 1 year after surgery. However, there seems to be a difference in the anterior capsule behaviour between both IOL models.
Journal of Cataract and Refractive Surgery | 2015
Guenal Kahraman; Michael Amon; Clara Ferdinaro; Karl Nigl; Michael Walch
Purpose To compare the 3‐year postoperative anterior (ACO) and posterior (PCO) capsule opacification and the level of anterior capsule retraction after implantation of 2 single‐piece hydrophobic acrylic intraocular lens (IOL) models. Setting Hospital of St. John of God, Vienna, Austria. Design Comparative randomized controlled double‐blind clinical trial. Methods Eyes with bilateral cataract were evaluated. Each patient had an Acrysof SA60AT (interrupted optic edge) IOL implanted in 1 eye (Group A) and a Tecnis ZCB00 (continuous optic edge) IOL implanted in the fellow eye (Group B). One and 3 years postoperatively, PCO was evaluated using Evaluation of Posterior Capsule Opacification software and the ACO level and capsule‐retraction level were evaluated and graded subjectively. Results The study evaluated 100 eyes of 50 patients ranging from 61 to 80 years. Postoperatively, there were no statistically significant differences in PCO between Group A and Group B at 1 year (0.06 ± 0.12 [SD] and 0.07 ± 0.13, respectively; P = 4.35) or 3 years (0.23 ± 0.36 and 0.22 ± 0.32, respectively; P = .66). In Group A and Group B, ACO was present in 18.0% of eyes and 2.7% of eyes, respectively, at 1 year (P = .03) and in 92.0% and 24.0%, respectively, at 3 years (P < .01). Capsule phimosis (18.0% at 1 year; 30.0% at 3 years) and glistenings (66.0% at 1 year; 86.0% at 3 years) were observed in Group A only. Conclusion Both IOLs had similarly low PCO rates 3 years postoperatively, although more ACO and capsule retraction were observed in eyes with the interrupted optic edge IOL. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.
European Journal of Ophthalmology | 2016
Barbara Wetzel; Georgios Mylonas; Franz Prager; Guenal Kahraman; Clemens Bernhart; Robert Lux; Michael Amon
Purpose To describe a case of epiretinal membrane (ERM) regression after optic nerve atrophy. Methods Retrospective case report. Results A 56-year-old man with progressive visual impairment was found to have an ERM with associated retinal thickening and distortion (documented with spectral-domain optical coherence tomography [OCT]). In addition, we noted a slight unilateral paleness of the optic nerve. The patient denied any further diagnostic investigation and presented himself again 2 years after the initial presentation. A new OCT examination at this point revealed a remarkable regression of the ERM and atrophy of the retinal nerve fiber layer. Conclusions Regression of ERM may occur after optic nerve atrophy. A potential causal linkage is suggested based on the atrophy of the retinal nerve fibers and regression of the glial cells.
Archive | 2014
Michael Amon; Guenal Kahraman
High biocompatibility is one of the main features expected of an intraocular lens (IOL) implant. In terms of anatomical position an implant is close to, or in contact with, uveal tissue and the capsule. Therefore, uveal reactions of the eye must be distinguished from capsular reactions. As both reactions are influenced by the implant, one should rightly address the subjects of uveal biocompatibility and capsular biocompatibility separately. The iris, the ciliary body, and the choroid are composed of vascularized tissue and are close to the implant. In cases of iridolenticular synechiae or sulcus position of the IOL, portions of the lens come into direct contact with uveal tissue. Changes in blood-aqueous barrier due to surgical trauma and the implanted foreign body cause leakage of proteins and macrophages from blood.
European Ophthalmic Review | 2011
Michael Amon; Guenal Kahraman
Summary: An overview on polypseudophakia (‘piggyback’ intraocular lens [IOLs]) is given. Requirements on a sulcus-supported supplementary IOL are defined. Two-year results of a new IOL (Sulcoflex®) are presented and indications for this IOL are defined. Methods: The IOL is especially designed for implantation into the ciliary sulcus in pseudophakic eyes (piggyback). It is a single-piece implant made of hydrophilic acrylic. Opticand haptic-edges are round. The optic has a diameter of 6.5mm and a concave/convex shape for perfect fit on the anterior convex surface of the primary IOL. The haptic is angulated, and has an undulated design to preclude IOL rotation. A monofocal, a multifocal or a toric version of the sulcoflex IOL were implanted into the ciliary sulcus of pseudophakic eyes. All IOLs were implanted by injector through a 3mm clear cornea incision. After surgery near and far uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) and eye pressure were assessed. Inflammation was measured by laser flare/cell meter. Position and rotational stability of the IOL were documented regularly at all control visits. Furthermore, Scheimpflug photography and ultrasound biomicroscopy were performed. Results: Surgery was performed without any complication in all cases. Two years after surgery there were no severe intraor post-operative complications detected. Emmetropia was achieved in all cases (±0.25dpt) and the refraction was stable. Flare values were lower than the values measured after standard cataract procedures. Rotational stability and centration were excellent. Intraocular pressure was within the normal range at all visits. After one year of follow-up no iris-chafing was documented. In all cases, a good distance was found between iris and the Sulcoflex-IOL and primary implant and the Sulcoflex-IOL. In those cases with the multifocal IOL-version all patient achieved independency from glasses. Conclusion: Surgery with implantation of a sulcus-IOL is safe and less traumatic than IOL-exchange. The material and design of the Sulcoflex IOL ensure that the implants are well tolerated within the eye. The implant can be used at the same time with the primary implant or as secondary implant. Indications for implantation of this IOL are the correction of ‘post-surgical’ ametropia, of astigmatism (toric IOL) of higher order aberrations (aspherical IOL) and of ‘pseudophakic presbyopia’ (multifocal IOL). In the future, other potential indications will be established.
Journal of Cataract and Refractive Surgery | 2017
Guenal Kahraman; Clara Ferdinaro; Barbara Wetzel; Clemens Bernhart; Franz Prager; Michael Amon
Journal of Cataract and Refractive Surgery | 2017
Franz Prager; Michael Amon; Joerg Wiesinger; Barbara Wetzel; Guenal Kahraman