AIM: To determine the effects of a low dose latrunculin (LAT)-A on dexamethasone (Dex)-induced upregulation of extracellular matrix proteins fibronectin (FN) in cultured human trabecular meshwork (HTM) cells. METHODS: HTM cells were cultured to confluent and incubated with 0.4μmol/L Dex and/or 0.05μmol/L LAT-A. FN expression in HTM cells was evaluated by Western blot and immunofluorescence microscopy. RESULTS: Dex up-regulated FN production in HTM cells, failed to do so when co-incubated with LAT-A. LAT-A decreased production of FN in cultured HTM cells. CONCLUSION: This study indicated that LAT-A may modulate the expression of fibronectin in trabecular meshwork to achieve treatment for steroids and other types of glaucoma. It has an important prospect as an intraocular pressure- lowering drug.