Scanning electron microscopy of normal and lased rabbit pigment epithelium

Scanning electron microscopic (SEM) observations of the rabbit retinal pigment epithelium (RPE) are reported both for normal tissue and for tissue subjected to laser radiation. In normal RPE, cells were observed to be closely packed and to have the characteristic hexagonal shape. The microvilli were abundant and of two types. Suprathreshold lesions were produced with 0.4 musec pulses of high-intensity yellow light (585 nm.) from a dye laser. In the lased RPE, cells were denuded of their microvilli, and a number of cells with single discrete holes were observed. Hypertrophied cells were always present. Within 5 days of irradiation groups of small proliferating RPE cells were found in the lesion area.