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Pharmaceutical Applications of Collagen
Published in Amit Kumar Nayak, Md Saquib Hasnain, Dilipkumar Pal, Natural Polymers for Pharmaceutical Applications, 2019
K. Sangeetha, A. V. Jisha Kumari, E. Radha, P. N. Sudha
The first report on corneal collagen cross-linking (CXL) was done by a group of German researchers in the year 2003 to arrest the progression of keratoconus and LASIK-induced ectasia which was generally termed as “post-refractive surgery ectasia. This method will preserve the natural architecture of cornea and thereby prevent the shape of the cornea (as domed shape) without growing steep and irregular. In other words, collagen cross-linking will helps to delay the transplantation of cornea in patients affected by Keratoconus or LASIK. In this technique, riboflavin was used as a photosensitizer, and Ultraviolet-A was employed to maximize intra and interfibrillar covalent bonds formation by photosensitized oxidation (Jankov et al., 2010).
Vecto-keratometry: determination of anterior corneal astigmatism in manual keratometers using power vectors
Published in Expert Review of Medical Devices, 2023
Raquel Salvador-Roger, Rosa Vila-Andrés, Vicente Micó, José J. Esteve-Taboada
It is worthy to note that, in this research, keratometric readings were obtained in corneas having regular astigmatism, hence final conclusions cannot be extrapolated to populations excluded from this study, such as irregular corneas. Future studies would evaluate the results that would be obtained in the case of inexperienced observers and should provide new information in such populations. However, the possibility of having irregular corneas is in odds with the use of conventional keratometry. Helmholtz’s keratometers would provide an error since it assumes orthogonality in the measurements, while Javal’s keratometer would introduce an uncertainty because both readings will not be separated by 90 degrees, introducing doubts for dealing with the proper orthogonalized measurements. For those cases (something appearing frequently in regular population without being affected by keratoconus, ectasia or any other corneal pathology) the proposed methodology might directly provide a result assuming regular astigmatism without the need to apply additional more complex method [39,40].
The STENTYS self-apposing stent technology in coronary artery disease: literature review and future directions
Published in Expert Review of Medical Devices, 2018
Huangling Lu, Robbert J. De Winter, Karel T. Koch
The incidence of coronary artery ectasia varies between 1.5% and 5% during coronary angiography in large registries [11,12]. There is an overlap of this condition with coronary artery aneurysms, which is more focal in nature, in the literature. Coronary aneurysm is generally defined as localized or segmental dilatation that exceeds the diameter of normal adjacent segments by 1.5 times [13]. The mechanism of the development of coronary ectasia or aneurysm is not yet fully understood. A potential cause of coronary artery ectasia is outward remodeling due to atherosclerosis, which is found in more than 50% of cases. Other contributing factors are connective tissue disease, Kawasaki disease, inflammatory arterial diseases, infectious causes, congenital coronary artery disease, and idiopathic or secondary to PCI procedures [14,15]. Isolated coronary ectasia or aneurysms are associated with a long-term mortality rates that vary from 15% to 29% at 1 and 5 years, respectively[16]. Data on patient outcome after PCI of stenotic lesions involving coronary artery ectasia or aneurysm is limited to case reports. Patients could benefit from the nitinol platform, which is able to appose to the aneurysmatic coronary artery wall as demonstrated in a model as well as in vitro using stent boost (Figure 2).
Biomechanical analysis of corneal keratoconic disease
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
N. Falgayrettes, E. Patoor, F. Cleymand, J-M. Perone
The cornea is the outermost transparent tissue of the eye composed of five distinct layers. The keratoconus disease is described as a progressive and non-inflammatory corneal ectasia caused by decrease in the biomechanical strength of the tissue. As the cornea becomes thinner and softer, it cannot support the inner eye pressure anymore and assumes a conical shape which leads to increasingly blurred vision (Ferrari and Rama 2020).