(530f) In Vitro Studies Of Selective Targeting Of Pigmented Retinal Pigment Epithelial (Rpe) Cells And Subsequent Bio-Stimulation

This work focuses on the development of a procedure to selectively target pigmented retinal pigment epithelial (RPE) cells using a, one microsecond duration, single pulse dye laser while sparing the adjacent non-pigmented cells or structures for the treatment of age-related macular degeneration. We demonstrate that laser-induced damage was confined to pigmented RPE cells, permitting selective targeting of these cells without producing collateral thermal damage to adjacent non-pigmented cells. A fluorescent assay was used to evaluate the threshold for laser induced damage as a function of laser fluence and intercellular melanin. Most importantly, subthreshold exposure to laser irradiation (<120 mJ/cm2) was shown to enhance RPE cell proliferation and migration. Preliminary results suggest that increased expression of PDGF might be the relevant mechanism. Our approach aims to elucidate the fundamental biological mechanisms for RPE regeneration in vivo following selective photocoagulation and suggest novel avenues for treatment.