98th Annual Meeting DOG 2000

P 644

Low dose ionidizing irradiation for inhibition of posterior capsule opacification in vivo

A. M. H. Foerster1, B. Huppertz1, H.-R. Koch, K. Carnphausen2, A. Lappas1, B. Kirchhof1, A. M. Joussen1,2

Introduction: Secondary cataract formation limits visual function after cataract surgery. Various experimental methods utilizing the pharmacological inhibition of lens epithelia1 cell proliferation have been proposed. However, diffusion of these pharmacologic agents into the anterior charnber may lead to darnage of comeal endothelia1 cells. This study eva1uated the inhibition of lens epithelia1 cell proliferation with a capsular bag ring, which was labeled with a ß-emitting radioisotope prior to implantation.

Methods: P-32labeled PMMA rings were implanted into the capsular bag of NZW rabbits in vivo after phacoemulsification. Anima1s were exarnined for development of posterior capsule opacification over a period of 12 weeks following surgery. Radiation damage to the su1Tounding ocular tissue was subsequently ana1yzed in histologica1 sections using TUNEL assay and the proliteration markers PCNA and Mib-l.

Results: In vivo, implantation of P-32 labeled PMMA rings lead to inhibition of epithelia1 cell proliferation and secondary cataract formation, but was not able to fully inhibit fibrotic changes. Histologica1 exarnination showed no evidence of radiation damage of the ciliary body or the comea1 endothelium.

Conclusion: Low dose beta irradiation exhibits the potentia1 for inhibition of lens epithelia1 cell proliferatioh in vivo. Further investigation of various nuclides and their radiation profiles is needed to optimize the prevention of posterior capsule opacification due to epithelial cell proliferation.

1Augenklinik der RWTH Aachen, Pauwelsstr. 30, D-52057 Aachen
Children's Hospital, Harvard Medical School, Boston MA, USA
(DFG Jo 324/2-1, START 2000-1 Jou, RWTH Aachen)