Inhibition of posterior capsule opacification by an intraocular-lens-bound sustained drug delivery system: an experimental animal study and literature review.

PURPOSE

To find a way to prevent or significantly reduce posterior capsule opacification (PCO) with modern phacoemulsification and in-the-bag intraocular lens (IOL) implantation.

SETTING

Department of Ophthalmology and Institute for Pharmaceutical Technology and Biopharmacy, Ruprecht-Karls-University of Heidelberg, Germany.

METHODS

We evaluated the effects of an IOL-bound sustained drug delivery system (SDDS) consisting of the carrier substance poly-DL-lactid and the drug daunorubicin or indomethacin. The system was applied to the IOL surface and implanted in rabbit eyes. At 8 weeks postoperatively, PCO wet mass was determined. Toxic and inflammatory effects were documented by histopathology.

RESULTS

The average PCO wet mass was 54.6 mg in the control group, 28.6 mg with daunorubicin, and 64.1 mg with indomethacin. Statistical analysis showed a significant reduction of PCO with daunorubicin (Mann-Whitney U-test, P = .025) and no PCO-reducing effect with indomethacin. Light microscopy of the specimens revealed mild inflammation, especially at the limbus, and some endothelial cell loss in the daunorubicin group and iris and ciliary body inflammation in the indomethacin group.

CONCLUSION

In the rabbit eye, slow release of daunorubicin reduced PCO formation by approximately 50%. It must be determined whether the endothelial side effects are specific to the rabbit species or whether the human cornea is as sensitive. The principle of the IOL-bound SDDS and the evaluation procedure can be standardized and used for systematic tests in the future.