[Advances in clinical diagnosis and treatment of pythium keratitis].

Pythium insidiosum is an aquatic algal oomycete that can induce Pythium insidiosum keratitis (PIK). PIK typically presents as acute, highly invasive corneal ulcers, rapidly progressing to corneal dissolution and perforation, and in severe cases, may lead to blindness. Due to its clinical presentation resembling fungal infections, it is often misdiagnosed as fungal keratitis. Epidemiological studies indicate that PIK is predominantly found in tropical and subtropical regions, with a higher incidence during the monsoon season. It is often associated with exposure to contaminated water sources or minor trauma caused by plants. Diagnostic methods include staining of corneal scrapings, PCR, metagenomic next-generation sequencing, and confocal microscopy. Since PIK shows a poor response to conventional antifungal treatments, antibiotics are the preferred treatments, with a combination of linezolid and azithromycin often used as the first-line therapy. Severe cases may require penetrating keratoplasty. In China, reports of PIK cases are relatively rare. This review summarizes the epidemiology, etiology, clinical manifestations, diagnosis, and treatment of PIK, aiming to provide a reference for its clinical management.