View clinical trials related to Tomography, Optical Coherence.
Filter by:To observe the retinal microvascular alteration during 3 months follow-up after Implantable Collamer Lens (ICL) operation in moderate and high myopia patients using quantitative optical coherence tomography angiography (OCTA) analysis.
OCTA-guided PDT is as safe and effective as ICGA-guided PDT in the treatment of acute central serous chorioretinopathy. Or OCTA-guided PDT is more effective than ICGA-guided PDT in the treatment of acute central serous chorioretinopathy, safe as well.
Optical Coherence Tomography (OCT) is a relatively new imaging technique in ophthalmology. This clear and documented imaging identified new diseases/ observations that were not previously known.
Improvement of retinal medical imaging opens new perspectives for exploring the retinal structures. Optical coherence spectral domain (SD-OCT), which has been widely used in the last ten years, is certainly the most advanced device. In the analysis of patients without retinal disease using SD-OCT, granulations in the interdigitation area were observed. These granulations have never been described with this device. They could correspond either to the degradation products of the external segments of the photoreceptors or to melanosomes. A descriptive study of these granulations at different examination times and in different lighting situations would allow us to obtain essential information for a better understanding of this area. Based on the results, larger studies could explore this area more finely in retinal pathologies involving dysfunctions of photoreceptors or of the pigmentary epithelium.
Knowledge of the evolution of multiple sclerosis (MS) and its long-term prognostic factors is essential to guide the therapeutic management. However, it remains partial and concerns above all data collected during the first years of the disease. The evolution towards disability can only be assessed after a follow-up of more than 10 years and does not depend solely on the initial inflammatory activity of the disease. We propose to realize a standardized clinical assessment, an optical coherence tomography (OCT) and a cerebral MRI 15 years after the first clinical manifestation of the disease. Clinical and paraclinical assessment will consist in the realization of additional MRI sequences in order to obtain more precise information on cerebral lesions (unconventional parameters). Optical coherence tomography (new generation device) will also be performed on both eyes to describe the thickness of the different layers of the retina. A clinical evaluation will be performed with the Expanded Disability Status Scale (EDSS). This study aims: 1. to describe the current clinical situation of patients (e.g. percentage of patients with moderate or severe disability) 2. to explore the associations between MRI parameters, those measured with OCT and clinical characteristics (disability) 3. to explore clinical and paraclinical prognostic factors of pejorative evolution (disability, severe cerebral atrophy, etc.)
This study evaluates the relationship between BMO-MRW and RNFL thickness measured by OCT. SD-OCT exam will be performed to all patients in this study.
Bioresorbable vascular scaffold (BVS, ABSORB BVS1.1, Abbott Vascular) has been approved (CE mark) and is used in daily clinical practice. While recent randomized controlled trials comparing BVS versus metallic drug-eluting stent showed higher risk of definite or probable device thrombosis after BVS implantation, the causes underlying thrombotic events occurring beyond one year after scaffold implantation remain unclear and require investigation in an independent manner. The INVEST registry is a world-wide, multi-center, observational, retrospective, investigator-initiated registry, which will include any patients who suffered from very late (>1 year) scaffold thrombosis, underwent optical coherence tomography (OCT) at the time of thrombosis and provided informed consent for the further use of their health related data for this registry.
This study is a prospective, multi-center, open-label, randomized controlled clinical trial,aims to assess the safety and effectiveness of the Firehawk™ sirolimus target-eluting coronary stent system with abluminal grooves containing a biodegradable polymer (Firehawk™) comparing the XIENCE everolimus-eluting coronary stent system in the treatment of subjects with total coronary occlusion lesion(s).
The study will compare two invasive methods (FFR -fractional flow reserve and iFR—instantaneous wave free ratio) for assessment of hemodynamic impact of coronary stenosis on myocardial perfusion. There is a very good correlation between these methods for the assessment of hemodynamic significance in a broad spectrum of lesions. However, this correlation decreases significantly near the cut off points for each method. The investigators will try to find possible explanations for these differences by detailed morphology assessment of coronary stenosis using optical coherence tomography (OCT), analysis of gene polymorphisms that play a role in vasodilatation, and by shear stress analysis. The head-to-head comparison between FFR and iFR is not simple, because there is no "gold standard" for assessment of hemodynamic significance. Studies comparing these methods have used hyperemic stenosis resistance (HSR). For this kind of measurement it is necessary to measure the speed of blood flow. This is usually done by a Doppler analysis of flow. Unfortunately, the Doppler signal can yield many artificial or erroneous indicators, and obtaining a good quality signal is frequently time-consuming. These are the reasons that HSR has not been used in routine practice. The investigators have developed a new console and software that can provide real time analysis of the Doppler signal. It allows us to easily measure HSR, and to differentiate between the FFR and iFR measures through intrabeat analysis of microvascular resistance (lowest microvascular resistance is an essential condition for proper pressure measurement). Using this tool, it is possible to automatically identify the point of lowest microvascular resistance during each cardiac beat. The pressure gradient can then be measured at that point. This approach can eliminate almost all uncertainties in assessment of the pressure gradient produced by coronary stenosis. This tool can potentially improve the existing methods used to precisely reveal a significant stenosis. This should increase the number of hemodynamic guided procedures.
Study designed to determine the ability and accuracy of anterior segment optical coherence tomography (AS-OCT) to measure the distance between the corneoscleral limbus and the insertion site of the extraocular muscles (EOM) in adults with and without previous strabismus surgery. And to compare in surgical patients the pre-operative AS-OCT limbal-muscle insertion distance measurement to the intraoperative limbal-muscle insertion measurement using calipers (gold standard).