Absorbable intracanalicular collagen implants were placed in both canaliculi of one eye of nine human volunteers. The other eye served as a control. Twenty-four hours later 2% sodium fluorescein was placed into both conjunctival sacs. Serial corneal fluorescein concentrations were measured with a scanning ocular fluorophotometer from 2 to 90 min after fluorescein administration. The mean corneal fluorescein concentration averaged over all time points was greater in 7 of 9 eyes with collagen implants compared to unimplanted controls. When the data from each subject were analyzed collectively, the mean corneal fluorescein concentration in the implanted eyes (1,218 micrograms/ml +/- SEM 83) was significantly greater (p less than 0.001) than the mean concentration in the control eyes (823 micrograms/ml +/- SEM 83). The use of absorbable intracanalicular collagen implants may increase the bioavailability of topically applied ocular solutions.