Paving-stone degeneration. A, Paving-stone degeneration appears as areas of depigmentation (arrows) in the periphery of the retina near the ora serrata. B, Histologically, paving-stone degeneration consists of atrophy of the outer retinal layers and adhesion of the remaining inner retinal elements to Bruch membrane. A sharp boundary (arrowheads) exists between normal and atrophic retina, corresponding to the clinical appearance of paving-stone degeneration.