Hypopyon from observation to insight: a multidimensional system involving pathogenesis, lesion nature, clinical manifestations and diagnosis and treatment

Hypopyon is a pivotal clinical sign guiding diagnosis, treatment selection and efficacy evaluation in ophthalmology. However, its overlapping etiologies, atypical presentations of rare emerging pathogens, and the lack of rapid differential tools between infectious and sterile inflammation frequently lead to delayed diagnosis, inappropriate management and irreversible visual impairment. Recent advances in multiplex molecular pathogen detection, quantitative AS-OCT imaging, and mNGS offer new perspectives for investigating the etiology of hypopyon. However, evidence that these modalities refine multi-dimensional phenotypic stratification remains limited, and challenges including variable diagnostic accuracy and the absence of standardized interpretation protocols persist. This review summarizes the pathogenesis, clinical features and classification framework of hypopyon, covering infectious/non-infectious origins, primary/secondary occurrence, and true hypopyon/pseudohypopyon. It provides an up-to-date, evidence-based reference for accurate differential diagnosis and individualized clinical management.