Systemic bias in medical consensus: how flawed panels and lack of evidence can distort definitions and guidelines: the case of Vogt-Koyanagi-Harada disease : Perspective.

backgroundThe creation of diagnostic criteria for a disease is always challenging in medicine. Consensus meetings and expert's opinions are sometimes responsible for establishing useful and precise diagnostic criteria but, unfortunately, not all the consensus meetings are based on evidence-based conclusions.

methodsA perspective analysis of the historical evolution of diagnostic criteria for Vogt-Koyanagi-Harada.

resultsWe examine the historical evolution of diagnostic criteria for Vogt-Koyanagi-Harada disease, an autoimmune condition targeting melanocyte-containing tissues, primarily affecting the choroid and potentially involving the skin, ears, and meninges. Early diagnostic criteria proposed in the late twentieth century were considered inadequate, leading to an international consensus conference in 1999 and the publication of revised diagnostic criteria in 2001. However, these criteria contained major conceptual flaws, notably the combination of acute and chronic clinical features that rarely occur simultaneously. In addition, important diagnostic tools such as indocyanine green angiography were largely excluded due to prevailing local practices and skepticism regarding their use. These limitations hindered accurate diagnosis and delayed recognition of VKH as a disease with distinct acute-onset and chronic forms requiring different diagnostic frameworks and management strategies. Subsequent studies corrected some deficiencies but often generated complex criteria difficult to apply in routine practice.

conclusionWe would like to emphasize the risks of poorly structured consensus processes and propose safeguards to ensure scientifically rigorous and clinically useful recommendations.