A small ulcer and an absolute sampling instruction

A fictional clinician is reviewing two corneal cases: a small peripheral infiltrate without stromal melting and a large central ulcer with substantial stromal involvement and an atypical exposure history. A trainee applies the same rule to both, saying every ulcer must be cultured and all treatment delayed until the sample can be obtained. The supervisor asks whether location, size, tissue threat, prior treatment and atypical features alter the need for microbiological investigation. The case does not supply an individual antimicrobial order or complete susceptibility result. Its purpose is to connect sampling to the diagnostic question and urgency, while preserving the principle that a sight-threatening infection requires timely appropriate clinical care.