['To explore the effect of ethanol treatment on corneal stromal cells.', 'Primary porcine corneal fibroblasts from passages 3 to 5 were treated with ethanol at concentrations of 10%, 15%, 20%, and 50% for 30 seconds. A control group was treated with phosphate-buffered saline (PBS) for 30 seconds. Morphologic changes were documented with phase-contrast microscopy, and the growth curves were examined with a PicoGreen assay. Cellular viability was examined with an ethidium homodimer and calcein-AM stain, whereas cellular apoptosis and/or necrosis were analyzed by a YO-PRO-1 dye/propidium iodide apoptosis assay coupled with flow cytometry and further confirmed with a genomic DNA pattern assay. Cellular toxicity was examined with a lactate dehydrogenase (LDH) assay.', 'Significant cell rounding and detachment from the culture dish were noticed after 20% ethanol treatment of 30 seconds, despite that the cell morphology remained unchanged in the PBS and 10% and 15% ethanol groups. Twenty percent ethanol induced significant cellular toxicity, causing cell death as shown by ethidium homodimer and calcein-AM stain, YO-PRO-1 dye/propidium iodide apoptosis assay, and LDH assay, although 10% and 15% ethanol caused minimal changes to corneal fibroblasts. Cellular death was most significant 6 hours after the 20% ethanol treatment. The genomic DNA pattern revealed intact DNA in the control, 10% ethanol, and 15% ethanol groups at all times, whereas DNA smearing was noticed at 48 hours after the 20% ethanol treatment. However, none of the DNA examined revealed significant DNA laddering patterns of apoptosis. Fifty percent ethanol treatment of 30 seconds resulted in cell fixation and cell death.'] Does ethanol treatment induce significant cell death in porcine corneal fibroblasts?