Collagen shield delivery of tobramycin to the human eye.

Author(s): Taravella M, Stepp P, Young D

Affiliation(s): Department of Ophthalmology, University of Colorado School of Medicine, Denver, USA.

Publication date & source: 1998-07, CLAO J., 24(3):166-8.

Publication type: Clinical Trial; Randomized Controlled Trial

PURPOSE: The purpose of this study was to determine the ocular penetration of tobramycin into the anterior chamber of the human eye when delivered by a pre-soaked collagen shield. METHODS: We conducted a prospective, randomized study of 32 patients undergoing cataract surgery. The subjects were divided into two groups. The first group received three preoperative drops of commercially available combination tobramycin-dexamethasone drops at 15 minute intervals. In the second group, a collagen shield soaked in the same medication was applied to the eye prior to surgery. At the beginning of surgery, the aqueous humor was extracted for analysis. RESULTS: The samples from 11 patients could not be analyzed due to an insufficient aqueous sample. Of the remaining 21 patients, the mean aqueous concentration was 0.026 microgram/mL (range: 0.0-0.09) in the drops group and 0.024 microgram/mL (range: 0.04-0.8 microgram/mL) in the shield group. This difference was not statistically significant. The aqueous concentration in both groups did not approach the minimum inhibitory concentration (4 micrograms/mL) for common ocular pathogens. No adverse effects related to the use of collagen shields occurred. CONCLUSIONS: Perioperative use of a pre-soaked collagen shield utilizing a commercially available preparation of tobramycin-dexamethasone combination drops appears safe. However, the use of this system to prevent endophthalmitis is not warranted based on the concentrations obtained from the aqueous humor.