The effects of red light with different intensity on retinal photoreceptor cells in rabbit: an ultrastructural study

The purpose of this research was to investigate the fine structure of the photoreceptor layer of male rabbits exposed to intermittent red light with different intensities. Thirty adult male rabbits were divided into three groups: control group, experimental group 1 (exposed to 3 h/3 h 60 W red light) and experimental group 2 (exposed to 3 h/3 h 100 W red light). The retina of the eye was removed and studied by transmission electron microscope. Results showed that the experimental group 1 exhibited slight loss of mitochondrial cristae and vacuolization in inner segment, but the other layer of photoreceptor appeared normal. Disorganization and loss of outer segment showed in experimental group 2. Vacuolization, loss of mitochondrial cristae, cell swelling, and pyknotic nuclei were observed in this group. These findings indicate that intermittent red light cause damage in the photoreceptor layer of the rabbit retina; also, higher light intensity increased these damages.