[Microbiological diagnosis of ocular surface infections aside from virology]

The ocular surface is a structure exposed to multiple stresses that can directly or indirectly lead to infectious contamination and compromise visual function. This significant risk justifies multidisciplinary care, often in an emergency context, bringing together ophthalmologists and microbiologists to optimize and guide microbiological testing on small volume samples and ensure the most appropriate treatment. Herein, we present the various steps leading to microbiological diagnosis, from pre-analytical requirements, sampling methods, transport conditions, and then to the analytical steps of pathogen identification. These are based on microscopic examination associated with culture techniques, pathogen identification using mass spectrometry and molecular biology approaches and finally, antimicrobial susceptibility testing. Molecular biology methods have become important for the diagnosis and detection of antibiotic resistance genes, improving the identification rate of microorganisms, reducing the time needed to obtain results, and thus improving therapeutic management. Nevertheless, direct microbiological examination and culture remain the gold standards in the diagnosis of many ocular infections.