Selective damage of pigmented cells by means of a rapidly scanned cw laser beam

Selective targeting the retinal pigment epithelium (RPE) while sparing adjacent tissue such as the photoreceptors has been demonstrated by repetitively irradiating the fundus with a train of green microsecond(s) -laser pulses. The aim of this study was to investigate selective RPE effects alternatively by means of rapidly scanning a cw-laser beam across the RPE to obtain the required microsecond(s) -illumination times. The radiation of an Ar+ laser (514 nm) was transmitted through a 25-micrometers core diameter fiber to a scanner unit. The fiber tip was imaged onto the object plane with a magnification of 0.75. The beam was repetitively scanned across porcine RPE samples in vitro providing an irradiation time of 1.6 microsecond(s) . Cell damage was investigated with a fluorescence viability assay.

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