European Glaucoma Society - Terminology and guidelines for glaucoma, 6th Edition.

We practice medicine in times of exponentially increasing medical knowledge. In 1950, it was estimated that the doubling time was 50 years; by 1980, it was 7 years and by 2010, 3.5 years. In 2020, it was projected to be just 73 days! To continue to practice evidence-based medicine and to provide the best possible care for our patients, clinicians need to adapt their strategies to keep their knowledge up to date. There will always be a role for critical appraisal of individual studies in the field of a clinician's practice, but with such an increase in the volume of published research, it becomes impossible to appraise all relevant material. For this reason, sources of distilled knowledge, such as the EGS Guidelines, become essential references for best practice medicine. Rigorous methods for evidence synthesis, such as the systematic reviews overseen by Cochrane, provide a comprehensive summary of the current state of knowledge for important clinical questions. However, for many clinical uncertainties, there is little or no high-quality evidence, let alone an evidence synthesis. Where evidence is lacking, practice guidance needs to be built from expert opinion and consensus, while acknowledging the limitations of such an approach. Expert opinion, derived from sound medical knowledge and years of practice experience, also has an important role in understanding the relevance of lines of evidence and the nuances of implementing them in practice. Thus, the expert commentary around the evidence base given in these Guidelines is essential for proper implementation of published evidence. Importantly, the EGS Guidelines also include 'Choosing wisely' elements indicating actions which should be avoided due to insufficient evidence and/or unsubstantiated belief. Guidelines need regular updating to take account of new knowledge and aspects of clinical care that have not been given sufficient emphasis in the past. This 6th Edition of the EGS Guidelines includes an updated 'evidence based' section with new clinical questions and evidence-based answers. The section 'What matters to patients' has also been updated, recognising that, because Guidelines are typically written by clinicians for clinicians, there have been gaps in understanding the patient perspective. The updated section now has direct input from the Expert by Experience patient advisors in the EGS Patient Involvement Project and includes eight Tips for Doctors in their communication with patients. The Guidelines team, led by Drs Pazos, Traverso and Viswanathan, is to be congratulated for the 6th Edition of the Guidelines, updating and enhancing the previous edition, while maintaining the highly success format which gives a framework for glaucoma care, based on evidence synthesis and consensus expert opinion, and presented as a 'How to' manual for patient diagnosis and management. David (Ted) Garway-Heath Glaucoma UK Professor of Ophthalmology, UCL