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Robson-holder ring in retinitis pigmentosa. FAF (a) of retinitis pigmentosa shows an area of normal preserved retina at the posterior fundus bordered by a hyper-autofluorescent Robson-holder ring. Mottled hypo-autofluorescence outside the ring represents photoreceptor degeneration. These details are visible on FAF but not on fundus photography (b). Image courtesy of Heidelberg Engineering
