Purpose: To assess the feasibility of using recombinant adenovirus vectors to transduce the human lens epithelial cells (LECs) involved in posterior capsule opacification (PCO). Setting: Department of Ophthalmology and Molecular Medicine Unit, University of Manchester, Manchester, United Kingdom. Methods: Seventeen human lens capsules were maintained in organ culture to allow LECs to proliferate onto the posterior capsule. Partly covered and completely covered capsules were infected with a recombinant adenovirus vector RAd35, encoding for the marker gene β-galactosidase at plaque-forming units per milliliter (pfu/mL) ranging from 107 to 1010 for up to 48 hours. Assessment of infection and transduction of the marker gene were achieved by calculating the percentage of cells exhibiting X-gal staining both macroscopically and microscopically. Results: Staining appeared to be dependent on virus dose, with most intense staining at doses of 108 and 109 pfu/mL with decreased staining at higher and lower viral doses. Microscopic assessment demonstrated that all cells expressed β-galactosidase when infected with 109 pfu, 84% at 108 pfu, and 45% at 107 pfu. At 1010 pfu, some cytotoxicity was observed. Conclusions: These results indicate that recombinant adenoviruses can be used to transfer genes to the LECs involved in PCO. The transfer of cytotoxic genes after cataract surgery may be considered a preventive measure for PCO. (C) 2000 ASCRS and ESCRS.