• Previous studies showed that the combination of trifluridine with human leukocyte interferon in the treatment of dendritic keratitis is effective, and that the best results were obtained with the highest titer then available (30 × 106 IU/mL). The present study was undertaken to see if an even higher titer (100 × 106 IU/mL) would be more effective. A statistically significant greater effectiveness of the higher titer could not be verified.