High resolution ultrasonography of retinal degeneration in rat

We used 80 MHz ultrasonography to differentiate intra-retinal layers and assess retina degeneration in rats. Four eye groups taken from dystrophic and control RCS rats were explored ex-vivo at different degeneration stages using an ultrasound backscatter microscope. Ultrasound images were correlated to histology and the thickness of the photoreceptor layer structures was estimated over time. Ultrasound revealed a four layered retina including the photoreceptor outer nuclei and segment layers. Thickness decrease of the outer nuclei layer was related to retina maturation in controls and to retina degeneration in dystrophic groups. Ultrasound also revealed segment layer remodeling in the dystrophic group that was assigned to segment swelling at the early stage of the disease followed by disruption thereafter. Current findings demonstrate the great potential of the technique for the evaluation of therapy effects in vivo.