Line-Field Optical Coherence Tomography as a tool for In vitro characterization of corneal biomechanics under physiological pressures

Abstract There has been a lot of interest in accurately characterising corneal biomechanical properties under intraocular pressure (IOP) to help better understand ocular pathologies that are associated with elevated IOP. This study investigates the novel use of Line-Field Optical Coherence Tomography (LF-OCT) as an elastographic tool for accurately measuring mechanical properties of porcine corneas based on volumetric deformation following varying IOPs. A custom-built LF-OCT was used to measure geometrical and corneal surface displacement changes in porcine corneas under a range of IOPs, from 0–60 mmHg. Corneal thickness, elastic properties and hysteresis were calculated as a function of pressure. In addition, the effects of hydration were explored. We found that the elastic modulus increased in a linear fashion with IOP. Corneal thickness was found to reduce with IOP, decreasing 14% from 0 to 60 mmHg. Prolonged hydration in phosphate buffered saline (PBS) was found to significantly increase the elastic modulus and corneal hysteresis. Our study demonstrates that LF-OCT can be used to accurately measure the elastic properties based on volumetric deformation following physiological pressures. Furthermore, we show that prolonged hydration in PBS has a significant effect on the measured corneal properties

System and method for obtaining biomechanical parameters of ocular tissue through deformation of the ocular tissue

The invention relates to a system for obtaining biomechanical parameters of ocular tissue (C), the system comprising: - an air-puff module (200) configured to deliver at least one air-puff stimulus onto the ocular tissue; - an imaging device (100, 100') operatively coupled to the air-puff module (200); characterised in that - the air-puff module comprises a transparent window (PW) at its front thereof, the transparent window having a transparent through hole (OD) for delivering the at least one air-puff stimulus, the hole configured to be aligned with an optical axis of the imaging device, such that the air-puff stimulus delivered onto the ocular tissue can be centred on an apex of the ocular tissue and can be made collinear with the optical axis of the imaging device, the transparent window (PW) and its transparent through hole further allowing continuity of imaging of the ocular surface; - the imaging device (100, 100') being configured to capture the three-dimensional coordinates of a plurality of points distributed on a surface of the ocular tissue, captured in groups of at least two simultaneous points; the system further comprising: - means for selecting and changing the location and distribution of the plurality of captured points on a surface of the ocular tissue; - processing means configured to process the plurality of points provided by the imaging device for obtaining biomechanical parameters of the ocular tissue. The invention also relates to a method for obtaining biomechanical parameters of ocular tissue, especially, corneal biomechanical parameters.Peer reviewedConsejo Superior de Investigaciones Científicas (CSIC), Instytut Chemii Fizycznej, The University of LiverpoolA1 Solicitud de patente con informe sobre el estado de la técnic

A review of the most effective medicinal plants for dermatophytosis in traditional medicine

Fungi can evade the immune system via different processes, including recombination, mitosis, and expression of genes involved in oxidative stress responses. These processes can lead to chronic fungal diseases. Despite the growth of health care facilities, the incidence rate of fungal infections is still considerably high. Dermatophytes represent the main cause of cutaneous diseases. Dermatophytes attack keratinized tissues, such as nail, hair, and stratum corneum, due of their gravitation towards keratin, which leads to dermatophytosis. Medicinal plants have long been used to treat different diseases, and in the recent years, use of plant-based products to fight fungal, bacterial, and parasitic infections have attracted extensive attention. This is because the use of medicinal plants has many advantages, such as decreased costs and fewer side effects. This review article was conducted to report medicinal plants with anti-dermatophytosis properties. Seventy-six articles were retrieved from databases Google Scholar, PubMed, ScienceDirect, and Scopus. After exclusion of duplicate and irrelevant articles, 54 articles were selected. Of the remaining articles, 23 articles were screened and included in this study. According to the findings, Azadirachta indica, Capparis spinosa, Anagallisarvensis, Juglans regia, Inula viscosa, Phagnalon rupestre, Plumbago europaea, Ruscus aculeatus, Ruta chalepensis, Salvia fruticosa, Artemisia judaica, Ballota undulate, Cleome amblyocarpa, Peganum harmala, Teucrium polium, Aegle marmelos, Artemisia sieberi, Cuminum cyminum, Foeniculum vulgare, Heracleum persicum, Mentha spicata, Nigella sativa, and Rosmarinus officinalis are the most effective plants against dermatophytes which have been identified to date

Investigation of the corneal frequency response to modulated sound excitation

ARVO Annual Meeting Abstract, June 202