Delivery of fluorescein to the anterior chamber using the corneal collagen shield.

Collagen corneal shields show promise as an alternative method of drug delivery to the eye. The authors quantified collagen shield delivery of sodium fluorescein to the aqueous humor in human volunteers using fluorophotometry. Collagen shields that had been immersed in 0.01% sodium fluorescein were applied to eyes of human volunteers. The shields delivered significantly more fluorescein to the aqueous humor at 2 and 4 hours compared with drops of the same concentration instilled every 30 minutes for 4 hours (P less than 0.0001 and P = 0.0003, respectively) or daily wear soft contact lenses presoaked in 0.01% fluorescein (P less than 0.0001 and P less than 0.0025, respectively). Collagen shields did not induce damage to the corneal epithelium over a 2-hour wearing period. These results suggest that the collagen shield may be superior to topical drops in delivering water-soluble compounds to the cornea and aqueous humor.