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Makula-Pucker-Chirurgie mit und ohne Delamination der Membrana limitans interna bei Patienten mit Metamorphopsien / Macular pucker surgery with and without delamination of the internal limiting membraneKrüger, Christoph 26 June 2012 (has links)
No description available.
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The Relationship between Age-Related Macular Degeneration and Olfactory FunctionKar, Taner, Yildirim, Yildiray, Altundağ, Aytuğ, Sonmez, Murat, Kaya, Abdullah, Colakoglu, Kadir, Tekeli, Hakan, Cayonu, Melih, Hummel, Thomas 20 May 2020 (has links)
Background: Olfactory dysfunction is a common symptom of many neurodegenerative diseases, and age-related macular degeneration (AMD) is a late-onset neurodegenerative disease. Objective: Thus, the aim of this study was to investigate olfactory functions in patients with AMD. Methods: A total of 69 subjects with AMD and 69 age- and sex-matched healthy controls were enrolled. After a complete ophthalmic evaluation, the AMD patients were subclassified as earlyand late-stage AMD. Psychophysical testing of olfactory function was performed using the validated Sniffin’ Sticks test. Results: This study was carried out in 138 subjects, with a mean age of 74.3 ± 8.9 years (range 51–89). The current investigation showed the following two major findings: (1) patients with AMD had decreased olfactory abilities, especially in odor discrimination and odor identification, even at early stages compared to controls, whereas patients had decreased olfactory abilities in all subtasks of olfactory testings in advanced stages of AMD disease, and (2) as the visual acuity of AMD patients decreased, the olfactory abilities of these patients worsened. Conclusion: This study demonstrated that AMD had significant negative effects on all orthonasal olfactory tasks, particularly in advanced stages. Similar to other neurodegenerative diseases, odor discrimination and identification seemed to be more affected than odor detection threshold tasks.
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Häufigkeit des postoperativen Makulaödems nach primärer rhegmatogener Ablatio retinae / Incidence and Risk Factors for Cystoid Macula Oedema after Primary Rhegmatogenous Retinal Detachment SurgeryGebler, Marie 01 April 2020 (has links)
No description available.
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Značaj optičke koherentne tomografije makule kod glaukoma otvorenog ugla / Optical coherence tomography of macula in primary open angle glaucomaBabović Siniša 13 May 2016 (has links)
<p>Cilj ovog istraživanja je bio da se utvrdi da li postoji razlika u debljini makule kod pacijenata sa glaukomom otvorenog ugla (POAG) u odnosu na zdravu populaciju i u zavisnosti od stepena progresije bolesti, kao i da se utvrdi da li postoji povezanost između promene debljine makule i stepena oštećenja vidnog polja i debljine peripapilarnog sloja nervnih vlakana u zavisnosti od stepena progresije bolesti. Materijal i metode: U ovu kliničku prospektivnu studiju je uključeno 186 pacijenata. Na osnovu kliničkog nalaza formirane su tri grupe. Prva grupa (kontrolna – grupa zdravih): 68 pacijenata bez očnih oboljenja, sa najboljom korigovanom vidnom oštrinom ≥ 0.9, intraokularnim pritiskom (IOP) ≤ 21 mmHg, normalnim odnosom ekskavacije i površine glave vidnog živca i normalnim nalazom vidnog polja. Druga grupa (rani glaukom): 78 pacijenata sa klinički dijagnostikovanim primarnim glaukomom otvorenog ugla (sa karakterističnim oštećenjem glave vidnog živca i sloja nervnih vlakana retine i kod kojih je srednja vrednost devijacije standardne automatske perimetrije MD > -6 dB, prema Hodap klasifikaciji), bez drugih očnih ili sistemskih oboljenja, koja bi imala uticaj na nastanak glaukoma i sa najboljom korigovanom vidnom oštrinom ≥ 0.5. Treća grupa (glaukom srednjeg stepena): 40 pacijenata sa klinički dijagnostikovanim primarnim glaukomom otvorenog ugla (sa karakterističnim oštećenjem glave vidnog živca i sloja nervnih vlakana retine i kod kojih je srednja vrednost devijacije standardne automatske perimetrije -6 dB > MD > -12 dB, prema Hodap klasifikaciji), bez drugih očnih ili sistemskih oboljenja, koja bi imala uticaj na nastanak glaukoma i sa najboljom korigovanom vidnom oštrinom ≥ 0.5. Svim pacijentima je bio urađen kompletan oftalmološki pregled, kompjuterizovano vidno polje (Humphrey Field Analyzer, Carl Zeiss Meditec, Jena, Germany, SITA Standard, test C 24-2) i optička koherentna tomografija sloja nervnih vlakana peripapilarno i u predelu makule (SOCT Copernicus HR, Optopol Tech. SA, Zawiercie, Poland). Rezultati: Perifovea i parafovea, pokazuju statistički značajno smanjenje debljine i zapremine sloja nervnih vlakana u odnosu na stepen progresije glaukoma otvorenog ugla, pri čemu je ono naglašenije u perifovei (p<0,05). U svim segmentima makule (TPeriF, IPeriF, SPeriF, NPeriF, TParaF, SParaF, IParaF i NParaF) dolazi do smanjenja debljine i zapremine sloja nervnih vlakana sa progresijom bolesti (p<0,05). Segmenti makule TPeriF, IPeriF, a potom i SPeriF, prema navedenom redosledu, predstavljaju segmente sa najvećim potencijalom za predikciju ranih glaukomskih oštećenja s obzirom na uočeno najveće smanjenje debljine i zapremine nervnih vlakana (p<0,05). Segmenti makule SParaF i NParaF predstavljaju segmente sa najvećim potencijalom za predikciju napredovanja glaukomskih oštećenja srednjeg stepena s obzirom na uočeno najveće smanjenje debljine i zapremine nervnih vlakana (p<0,05). Debljina RNFL glave vidnog živca se statistički značajno smanjuje sa progresijom bolesti u svim posmatranim segmentima (p<0,05). Međusobni odnos između grupe zdravih i grupe pacijenata sa ranim glaukomom ukazuje da je statistički značajno smanjenje debljine RNFL prisutno u svim segmentima osim u segmentima P3 i P4 (p>0,05). Merenja debljine RNFL u segmentu P6 imaju najbolji potencijal za predikciju ranog glaukoma s obzirom na najizraženije smanjenje debljine nervnih vlakana upravo u ovom segmentu (p<0,05). Merenja debljine RNFL u segmentu P1 ima najbolji potencijal za predikciju dalje progresije bolesti. Debljina sloja nervnih vlakana makule srazmerna je smanjenju debljine RNFL na glavi vidnog živca, pri čemu je ona uočljivija na nivou segmenata koji su okarakterisani kao dobri prediktori za nastanak, odnosno progresiju bolesti (P6 sa IPeriF i TPeriF, odnosno P1 sa SPeriF), što dodatno naglašava njihovu važnost u dijagnostici glaukoma otvorenog ugla. Debljina makule kod pacijenata sa glaukomom otvorenog ugla je opisana umerenom do dobrom povezanošću sa stepenom oštećenja vidnog polja, pri čemu je ona najjača kod TPeriF, IPeriF i SPeriF segmenata i srazmerna je stepenu oštećenja vidnog polja. Koeficijenti korelacije između vrednosti srednje devijacije vidnog polja i debljine RNFL, odnosno sloja nervnih vlakana makule, pokazuju snažniju povezanost u odnosu na parametre dobijenog smanjenja debljine nervnih vlakana u makuli, što otvara mogućnost za dalja istraživanja. Segmenti glave vidnog živca i makule, koji su pokazali najbolju diskriminaciju u smislu predikcije nastanka POAGa, kao i oni koji sugerišu na njegovu progresiju, smešteni su na lokacijama koje su međusobno povezane opisanim prirodnim tokom nervnih vlakana. Zaključak: Optička koherentna tomografija makule je važna pomoćna metoda u dijagnostici glaukoma kojom je moguće izdvojiti pacijente sa ranim glaukomom u odnosu na zdravu populaciju, odnosno utvrditi progresiju glaukoma otvorenog ugla.</p> / <p>All patients underwent complete ophthalmologic examination, SAP (Humphrey Field Analyzer, Carl Zeiss Meditec, Jena, Germany, SITA Standard, test C 24-2) and optical coherent tomography scans of RNFL and macula (SOCT Copernicus HR, Optopol Tech. SA, Zawiercie, Poland). Results: Perifoveal and parafoveal nerve fiber layer have shown significant reduction of thickness and volume compared to stage of POAG progression, where perifovea showed higher significance (p<0,05). All macular segments (TPeriF, IPeriF, SPeriF, NPeriF, TParaF, SParaF, IParaF i NParaF) showed reduction in thickness and volume compared to disease progression (p<0,05). Macular segments TPeriF, IPeriF, as well as SPeriF, represent segments with highest potential to predict early glaucomatous damage according to the most significant reduction of nerve fiber layer thickness and volume (p<0,05). Macular segments SParaF and NParaF represent segments with highest potential to predict progression of POAG according to the most significant reduction of nerve fiber layer thickness and volume (p<0,05). Optic nerve head (ONH) RNFL thickness showed reduction compared to POAG progression in all segments (p<0,05). All ONH segments except P3 and P4 showed significant reduction of RNFL comparing control group to early glaucoma group patients (p>0,05). ONH segment P6 was found to be the highly specific for early glaucoma prediction according to the most significant reduction of RNFL thickness (p<0,05), while segment P1 was found to have highest potential for POAG progression. Macular nerve fiber layer thickness reduction follows ONH RNFL thickness reduction and there is mutual relation between both macular and ONH segments (P6 to IPeriF and TPeriF, P1 to SPeriF) with highest specificity for early defects and POAG progression. It was shown that macular thickness changes have moderate to good correlation with visual filed changes and it was highest in TPeriF, IPeriF and SPeriF segments. This correlation was found to be higher in macula then in ONH RNFL thickness changes, compared to visual field changes. Both macular and ONH RNFL segments, which were found to have highest specificity to POAG prediction and progression, are located in areas which mutually connect following natural course of nerve fiber layer between them. Conclusion: Optical coherence tomography of macula represents important ancillary method in POAG diagnosis and follow up, allowing to differentiate between early glaucoma patients and healthy individuals, as well as to determine progression of glaucomatous disease.</p>
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Morfološke karakteristike makule kao prognostički faktor poboljšanja vidne oštrine u terapiji pacijenata obolelih od dijabetesnog makularnog edema / Morphological characteristics of the macula as a prognostic factor of visual acuity improvement in the treatment of patients with diabetic macular edemaDžinić Vladislav 26 September 2016 (has links)
<p>Cilj ovog istraživanja je da se ispita uticaj centralne debljine makularne regije (CMT) i prisustva subretinalne tečnosti na vidnu oštrinu (VA) kod pacijenata obolelih od dijabetesnog makularnog edema, kao i uticaj očuvanosti kontinuiteta spoja spoljašnjeg i unutrašnjeg segmenta fotoreceptora (IS/OS – kompleks) i spoljašnje granične membrane (ELM) kao prognostičkih faktora u poboljšanju vidne oštrine nakon primenjene terapije kod pacijenata obolelih od dijabetesnog makularnog edema (DME). Materijal i metode: u ovu retrospektivno prospektivnu kliničku studiju nasumično je uključeno 100 pacijenata koji su podeljeni u dve grupe. Grupu A – prospektivni deo studije je činilo 50 pacijenata (50 očiju) kod kojih je dijagnostikovan dijabetesni makularni edem i kod kojih je inidikovana primena terapije, laserftotkogaulacije i/ili anti-VEGF terapije (bevacizumab). Grupu B – retrospektivnu grupu je činilo 50 pacijenata (58 očiju) koji su prethodno lečeni od dijabetesnog makularnog edema primenom laserfotokoagulacije i/ili anti-VEGF terapije (bevacizumab). Nakon kompletnog oftalmološkog pregleda koji se sastojao od određivanja vidne oštrine (optotipima po Snellenu), biomikroskopije, merenja intraokularnog pritiska i pregleda očnog dna – fundusa primenom panfundoskopa izvršena je optička koherentna tomografija u svih pacijenata (primenom aparata Stratus® OCT, Carl Zeiss, Meditec i Copercnicus® Optopol). Analiza OCT snimka, je obuhvatila određivanje centralne debljine makule (CMT), prisustva subretinalne tečnosti kao i procenu stanja očuvanosti kontinuiteta spoja spoljašenjeg i unutrašnjeg segmenta fotoreceptora (IS/OS kompleks) i očuvanost kontinuiteta spoljašnje granične membrane (ELM). CMT je izračunat primenom softvera OCT aparata i izražen kao srednja vrednost za svih 9 ETDRS polja. Prisutvno subretinalne tečnosti je klasifikovano kao pozitivno ukoliko je identifikovano makar u jednom preseku OCT tomograma .Očuvanost kontinuiteta IS/OS kompleksa i ELM je analizirana u svakom pojedinačnom snimku i podeljena u 3 kategorije. Prva – ukoliko je očuvano u svim presecima, druga – ukoliko je očuvano samo u pojedinim presecima i treća – ukoliko se IS/OS kompleks i ELM nisu mogli identifikovati na nalazu OCT tomograma. Rezultati ukazuju da prisustvo subretinalne tečnosti pre primenjene terapije nema statistički značajnog uticaja na poboljšanje vidne oštrine nakon primenjene terapije u pacijenata grupe A (pA=0,915), a statistička značajnost nije potvrđena ni kod pacijenata koji su prethodno tretirani od DME – grupa B (pB=0,772). Srednja vrednosti CMT i VA u pacijaneta grupe A iznosila je 474μm±140,67μm odnosno 0.25±0.20. Nakon primenjene terapije srednja vrednost vidnih oštrina iznosila je 0.41±0.25, dok su vrednosti srednje vrednosti CMT iznosile 343.68μm±99.03μm. Potvrđeno je statistički značajno poboljšanje vidne oštrine nakon primenjene terapije (pVA=0,0001) i statistički značajno smanjenje centralne debljine makule (pCMT=0,0001). Korelacija VA sa vrednostima CMT pre primenjene terapije pokazuje statističku značajnost sa negativnom korelacijom (r=-0,391; p=0,005) dok se nakon primenjene terapije ne uočava statistički značajna korelacija (r=-0,047; p=0,746). Analizom vrednosti CMT pre primenjene terapije sa vrednostima VA nakon terapije se uočava statistički značajna negativna korelacija, odnosno veće vrednosti CMT pre primenjene terapije ograničavaju poboljšanje vidne oštrine nakon primenjene terapije (r=-0,393; p=0,005). Evaluacija OCT tomograma, pre primenjene terapije, u pacijenata grupe A utvrđen je u potpunosti očuvan kontinuitet IS/OS kompleksa i ELM u svim presecima u 23 odnosno 27 očiju, u pojedinim presecima u 18 odnosno 16 očiju, i nije mogao biti identifikovan u 9 odnosno 7 očiju. U pacijenata grupe A nakon primenjene terapije uočava se statistički značajno poboljšanje vrednosti VA u zavisnosti od očuvanosti kontinuiteta IS/OS kompleksa (F=5,550, p=0,007) i ELM (F=5,428, p=0,008). Univarijantna odnosno multivarjiantna analiza podataka za granične vrednosti vidnih oštrina od 0,1 i koraka poboljšanja od 0,1 ukazuje na statističku značajnost prediktora IS/OS kompleksa (p=0,012 i p=0,032) i ELM (p=0,003 i p=0,018) u poboljšanju vrednosti vidnih oštrina nakon primenjene terapije. Pacijenti sa očuvanim kontinuitetom IS/OS kompelsa u svim presecima imaju 9,5 puta (OR=9,500 ) veću šansu za poboljšanje VA nakon primenjene terapije u odnosu na pacijente gde kontinuitet IS/OS kompleksa nije uočljiv. Pacijenti sa očuvanim kontinuitetom IS/OS kompleksa u pojedinim presecima imaju 7 puta veću šansu (OR=7,000) za poboljšanje vidne oštrine nakon terapije u poređenju sa onima kod kojih IS/OS nije uočljiv. Pacijenti sa očuvanim kontinuitetom ELM u svim presecima imaju 34,5 puta (OR=34,500 ) veću šansu za poboljšanje vidne oštrine u odnosu na pacijente gde ELM nije uočljiv. Pacijenti sa očuvanim kontinuitetom ELM u pojedinim presecima imaju 18 puta veću šansu (OR=18,000) za poboljšanje VA nakon terapije u odnosu na one kod kojih ELM nije uočljiv. Pored statistički značajnog uticaja očuvanosti kontinuiteta IS/OS kompleksa i ELM na poboljšanje vrednosti vidnih oštrina nakon primenjene terapije, uočava se i pozitvna korelacija između vidnih oštrina pre i nakon terapije (r=0,869; p=0,0001). U pacijenata grupe B srednja vrednost CMT odnosno VA iznosila je 253,72μm±75,27μm odnosno 0,68±0,29. Postoji statistički značajna razlika u vrednostima VA u odnosu na očuvanost kontinuiteta IS/OS kompleksa (F=107,913, p=0,0001) i ELM (F=25,619, p=0,0001). Poređenjem vrednosti parametara za obe posmatrane grupe uočava se statistički značajna razlika u vrednostima CMT koje su bile manje u grupi B (t=5,355, p=0,0001) i srednjim vrednostima VA ( t=5,137, p=0,0001) koje su bile veće u grupi B. Analizom očuvanosti kontinuiteta IS/OS kompleksa (χ2=0,119, p=0,730) i ELM (χ2=2,957, p=0,085) ne uočava se statistički značajna razlika. Zaključak: Odnos vidnih oštrina sa centralnom debljinom makule prikazuje različite vrednosti vidnih oštrina za iste vrednosti centralne debljine makule. Značajan uticaj na vidnu oštrinu pacijenata obolelih od DME ima očuvanost integriteta spoljašnje granične membrane (ELM) i spoja unutrašnjeg i spoljašnjeg segmenta fotoreceptora (IS/OS kompleks) evaluiranih na osnovu OCT snimka – tomograma. Očuvanost integriteta ELM i IS/OS kompleksa u svim presecima na OCT tomogramu pre primenjene terapije u pacijenta sa DME se mogu smatrati pozitivnim prognostičkim faktorom u poboljšanju vidne oštrine nakon primenjene terapije. U pacijenata kod kojih je kontinuitet ELM i IS/OS kompleksa očuvan u svim pravcima vrednost CMT pre primenjene terapije nema uticaj na poboljšanje vidne funkcije nakon terapije. Integritet IS/OS kompleksa i ELM ima pozitivnu korelaciju sa vidnom oštrinom bez obzira na vrstu primenjene terapije, anti-VEGF odnosno laserfotokoagulacije. Prisustvo subretinalne tečnosti ne utiče na vidnu oštrinu pacijenata obolelih od DME. Vrednosti VA pre terapije utiču na poboljšanje vidne oštrine nakon terapije.</p> / <p>The aim of this study was to investigate the influence of the central macular thickness (CMT) and the presence of sub retinal fluid on visual acuity (VA) in patients with diabetic macular edema, as well as the impact of preservation and continuity of the photoreceptor inner/outer segment junction (IS / OS - complex ) and external limiting membrane (ELM) as a prognostic factor in improving visual acuity after the applied therapy in patients with diabetic macular edema (DME). Materials and Methods: this retrospective - prospective randomized clinical study included 100 patients who were divided into two groups. Group A - a prospective part of the study, consisted of 50 patients (50 eyes), with the diagnosis of diabetic macular edema in which laser photocoagulation and / or anti-VEGF therapy (bevacizumab) was indicated. Group B - retrospective group, consisted of 50 patients (58 eyes), who were previously treated for diabetic macular edema either with laser photocoagulation and / or anti-VEGF therapy (bevacizumab). After complete ophthalmologic examination, which consisted of the determination of visual acuity (measured with Snellen charts), biomicroscopy, intraocular pressure measurement and inspection of the fundus, optical coherence tomography was performed in all patients (using the Stratus® OCT, Carl Zeiss Meditec and Copercnicus® Optopol). Analysis of OCT image, included the determination of the central macular thickness (CMT), presence of sub retinal fluid, as well as an assessment of the preservation of the continuity of the photoreceptor inner/outer segment junction (IS/OS - complex) and external limiting membrane (ELM). CMT is calculated using software of the OCT apparatus and expressed as the mean value for all 9 ETDRS fields. Presence of sub retinal fluid is classified as positive if it is identified in at least one cross-section of OCT tomogram. Preserved continuity of IS / OS complex and ELM is analyzed in each individual OCT cross-section image and divided into 3 categories. First - if it is preserved in all cross sections images, the second - if it is preserved only in certain sections and the third - if the IS / OS complex and ELM were not able to identify in OCT tomograms. The results indicate that the presence of sub retinal fluid before the applied therapy has no statistically significant effect on improving visual acuity after the applied therapy in patients of group A (pA = 0.915), and statistical significance was not also confirmed in any of the patients who were previously treated by DME - Group B (pB = 0.772). Mean CMT and VA values of patients in group A was 474μm ± 140,67μm and 0.25 ± 0.20. After receiving therapy mean visual acuity was 0.41 ± 0.25, while the value of the mean CMT was 343.68μm± 99.03μm. Significant improvement in visual acuity was achieved after the treatment in group A (pVA = 0.0001) together with statistically significant reduction in central macular thickness (pCMT = 0.0001). Correlation of VA with the values of CMT before applied therapy shows statistically significant negative correlation (r = -0.391; p = 0.005), while after the applied therapy statistical significance was not observed (r = -0.047; p = 0.746). Analyzing the values of CMT before the applied therapy with the values of VA after the treatment statistically significant negative correlation was observed, higher values of CMT before the applied therapy restrict visual acuity improvement after the applied therapy (r = -0.393; p = 0.005). Analyzing OCT tomograms in the patients in group A, before the applied therapy, fully preserved continuity of IS/OS complex and ELM in all the sections was found in 23 and 27 of the eyes, in certain sections in 18 and 16 of the eyes, and could not be identified in 9 and 7 eyes. Statistically significant improvement in VA, after the applied therapy, in patients in group A is observed, depending on the preservation of continuity of IS/OS complex (F = 5.550, p = 0.007) and ELM (F = 5.428, p = 0.008). Univariate and multivariate analysis with cut off VA value of 0.1 and step improvements of 0.1 points to statistically significant predictor of IS/OS complex (p = 0.012 and p = 0.032) and ELM (p = 0.003 and p = 0.018) in improving the VA after the applied therapy. Patients with preserved continuity of IS/OS complex in all sections are 9.5 times (OR = 9.500) more likely to improve the VA after receiving therapy compared to patients where continuity of IS/OS complex is not noticeable. Patients with preserved continuity of IS/OS complex in the some sections are 7 times more likely (OR = 7.000) for the improvement of visual acuity after treatment compared to those in which the IS/OS is not detectable. Patients with preserved continuity of ELM in all sections are 34.5 times (OR = 34,500) a greater chance to improve visual acuity compared to patients where ELM is not apparent. Patients with preserved continuity of ELM in the some sections are 18 times more likely (OR = 18,000) to improve the VA after treatment compared to those in which the ELM is not apparent. In addition to statistically significant impact of preservation of continuity of IS/OS complex and ELM for VA improvement after the treatment, statistically significant positive correlation between visual acuity before and after treatment (r = 0.869; p = 0.0001) was observed. In Group B patients, the mean CMT and VA value was 253,72μm±75,268μm and 0.68 ± 0.29. There is a statistically significant difference in the VA values compared to the preservation of continuity of IS/OS complex (F = 107.913, p = 0.0001) and ELM (F = 25.619, p = 0.0001). Comparing the values of parameters for both groups, statistically significant difference in CMT values and mean VA was observed. CMT values were lower (t = 5.355, p = 0.0001) while VA values were higher (t = 5.137, p = 0.0001), in group B. The analysis of preservation of continuity of IS/OS complex (χ2 = 0.119, p = 0.730) and ELM (χ2 = 2.957, p = 0.085) did not show a statistically significant difference. Conclusion: The relationship of visual acuity with central macular thickness shows the different levels of visual acuity for the same value of the central macular thickness. A significant impact on VA in patients with DME has maintained integrity of the external limiting membrane (ELM) and the photoreceptors inner/outer segments junction (IS/OS complex) evaluated on the basis of OCT - tomograms. Preservation of the integrity of the ELM and IS/OS complex in all sections of the OCT tomogram before applied therapy in patients with DME can be considered a positive prognostic factor in improving visual acuity after receiving therapy. In patients with preserved continuity of ELM and IS/OS complex in all sections before applied therapy the CMT value has no effect on the improvement of visual function after treatment. Regardless of the type of applied therapy, anti-VEGF and/or laser photocoagulation preserved integrity of IS/OS complex and ELM has a positive correlation with visual acuity. The presence of sub retinal fluid does not affect the visual acuity in patients with DME. The values of VA before treatment influence the improvement of visual acuity after treatment.</p>
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OCT (Optical Coherense Tomography) : Teknik och tillämpningLundkvist, Stefan January 2013 (has links)
Before year 1895, the doctors could only make a probable diagnosis based on what the patient could tell and it was hurt and there was no discernable change to the outside of the body. With X-ray, it was possible to see inside the patient without first cutting it, you can say that the X-ray was the starting point for diagnostic imaging.The further development of X-ray gave CT (Computed Tomography), where X-ray tubes and detectors rotate around the patient while the patient table moves. Besides CT also developed MRI (Magnetic Resonance Imaging), PET (Positron Emission Tomography) and Ultrasound. Common to these methods is that the produced 3D images.In 1990 a completely new approach for diagnostic imaging, OCT (optical coherence tomography), by measuring the phase shift and the intensity of reflected light, it provides real-time and non-destructive measurements (in vivo) a resolution of 1 to 15 microns, much higher than all other standard imaging techniques. You could say that OCT machine can be compared to ultrasound, which uses the reflection of sound waves to interpretation.The first OCT machines were of type TD (Time Domain), these had low resolution and low scanning speed. In 2005 came the SD-OCT, they had higher resolution and scanning speed, SD stands for spectral domain, SD-OCT is sometimes called FD-OCT as Fourier transformed signals and operating in the frequency domain.The development of OCT machines are only in their infancy, resolution, scanning speed and accuracy will increase all the time, this allows new uses and ways to diagnose developed. OCT can be used in such Oncology, MSD (Musculoskeletal disorders), cardiovascular medicine, teeth, nerves, but the largest field is the eye and then the back of the eye called the retina (retina).This thesis is limited to the eye, the purpose is to provide input to those who are likely to purchase an OCT-machine, but also show the measurement data OCT-machines are performing and how to use the OCT-machine more than to see age-related macular degeneration. Another aim is to increase understanding of the physics behind an OCT-machine for ease of understanding the output given.The manufacture/model that have selected for evaluation are Zeiss Cirrus 4000, Topcon 3D OCT-2000 and Heidelberg Spectralis, the reason is that there are only these three on the Swedish market and all are SD-OCT. The way to evaluate OCT-machines is to scan performance and what the various analysis programs can handle. Furthermore, each OCT-machine scans the macula and optic disk on a experimental person/ reference eye, in order to get the output of the precision, or if you want to call it repeatability, which is very important if one wants to follow a solitary disease course.The conclusion of this thesis is to OCT machines are quite similar. When it comes to ease of use when doing scans is the Cirrus is lightened by the use of the extra screen where you always look eye (iris camera), which makes it easy to adjust the sharpness and position of the mouse buttons. Topcon and Heidelberg is not difficult to use but requires more experience of the person making the OCT scans. Most measurement functions in the analysis program is Topcon and Heidelberg and best accuracy/repeatability is Heidelberg, both the macula and RFNL.OCT machine is a good tool to use on the anterior segment, but in the case the precision allows the precision used to monitor RNFL thickness changes in those with glaucoma. / <p>Validerat; 20131029 (global_studentproject_submitter)</p>
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