Histologic examination revealed degeneration the loss of the outer segment of the photoreceptors, decreased thickness of the outer retinal layers and in the vitreous These changes were progressed with the longer duration of the intravitreal replacement of perfluorodecalin. From the above resulgts, perfluorodecalin is thought to be unsuttable for the long-term witreous substitute and should be removed from the wyw before the vompletion of surgery.