Figure 2.

Drusen types in AMD macula have distinct geometry and ultrastructure. Cuticular, small hard and soft drusen in (A–F) high-resolution light microscopy and (G–I) transmission electron microscopy. (A–C) Drusen are found between the RPE-BL and the inner collagenous layer of BrM). Hard drusen and cuticular drusen are small with steep sides and contain dense hyalinized contents; cuticular drusen are numerous. Soft drusen are large and have sloping sides. BLamD and BLinD associate only with soft drusen (F) and not (D) cuticular drusen or (E) small, hard drusen. (G, H) Cuticular and small hard drusen are homogenous and electron dense, with small vacuoles attributed to extracted lipids distributed throughout. (I) Soft drusen are packed with ‘membranous debris' (considered partially preserved lipoproteins) and are continuous with BLinD, giving rise to a ‘soft' appearance in the fundus. Detachment of the retina from RPE is a postmortem artifact. Black arrows denote individual drusen. Images (A, D, G) taken from macular sections of the left eye of the patient with cuticular drusen. Scale bars: (A–C) 60, (D–F) 30, (G) 5, (H) 2, and (I) 5 μm. BM, basement membrane; CC, choriocapillaris. Reprinted with permission from Balaratnasingam C, Cherepanoff S, Dolz-Marco R, et al. Cuticular drusen: Clinical phenotypes and natural history defined using multimodal imaging. Ophthalmology. 2018;125:100–118. © 2017 by the American Academy of Ophthalmology.