Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications.

BACKGROUND: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. METHOD: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant. While screening tests for ectasia had been limited to corneal shape (geometry) assessment, clinical biomechanical assessment has been possible since the introduction of the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, USA) in 2005 and the Corvis ST (Oculus Optikgerate GmbH, Wetzlar, Germany) in 2010. Direct clinical biomechanical evaluation is recognized as paramount, especially in detection of mild ectatic cases and characterization of the susceptibility for ectasia progression for any cornea. CONCLUSIONS: The purpose of this review is to describe the current state of clinical evaluation of corneal biomechanics, focusing on the most recent advances of commercially available instruments and also on future developments, such as Brillouin microscopy.(undefined)info:eu-repo/semantics/publishedVersio

Genetic diversity in bambara groundnut (Vigna subterranea (L.) verdc.) as revealed by phenotypic descriptors and DArT marker analysis

Genetic diversity of a Bambara groundnut germplasm representing accessions from 25 African countries, maintained at the International Institute of Tropical Agriculture (IITA; Nigeria) was evaluated based on seed patterns, qualitative characters, quantitative traits and Diversity Arrays Technique (DArT) markers. The study aimed at identifying important descriptors for germplasm conservation, validating the crop’s geographical centre of origin and facilitating the utilization of existing genetic resources. Frequencies and diversity indices of seven types of seed patterns, 12 qualitative and 28 quantitative traits were evaluated for 124 representative accessions and were analyzed by region to elucidate the geographic distribution of descriptor states. In addition, individual plant samples from a subset of 40 landrace accessions were analyzed by assessing 554 DArT markers. Both the phenetic tree constructed from the qualitative and quantitative descriptors and the population structure derived from DArT marker analysis suggested a relatively high genetic diversity among accessions. Higher genetic diversity was observed for the Cameroon/Nigeria region relative to other regions, in agreement with the hypothesis that this region is the centre of origin for Bambara groundnut. Use of an extensive and diverse range of germplasm and an approach that integrated morphological and quantitative descriptors with DNA markers that represent wide genomic coverage offered a powerful way to make inferences about crop germplasm, in support of crop-improvement programs

Practice guidelines for endoscopic ultrasound-guided celiac plexus neurolysis

Objectives: The objective of guideline was to provide clear and relevant consensus statements to form a practical guideline for clinicians on the indications, optimal technique, safety and efficacy of endoscopic ultrasound guided celiac plexus neurolysis (EUS-CPN). Methods: Six important clinical questions were determined regarding EUS-CPN. Following a detailed literature review, 6 statements were proposed attempting to answer those questions. A group of expert endosonographers convened in Chicago, United States (May 2016), where the statements were presented and feedback provided. Subsequently a consensus group of 35 expert endosonographers voted based on their individual level of agreement. A strong recommendation required 80% voter agreement. The modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) criteria were used to rate the strength of recommendations and the quality of evidence. Results: Eighty percent agreement was reached on 5 of 6 consensus statements, 79.4% agreement was reached on the remaining one. Conclusions: EUS-CPN is efficacious, should be integrated into the management of pancreas cancer pain, and can be considered early at the time of diagnosis of inoperable disease. Techniques may still vary based on operator experience. Serious complications exist, but are rare