Morphology, Prevalence, Topography and Biogenesis of Subretinal Drusenoid Deposits in Non-Neovascular AMD
Researchers sought to characterize the morphology, prevalence and topography of subretinal
drusenoid deposits, a candidate histological correlate of reticular pseudodrusen, with reference to basal linear
deposit (BlinD), a specific lesion of age-related macular degeneration (AMD), and to propose a biogenesis model for
They postfixed donor eyes with median death-to-preservation of 2:40 hours in osmium tannic acid paraphenylenediamine
and prepared them for macula-wide high-resolution digital sections. They determined annotated thicknesses of 21
chorioretinal layers at standard locations in sections through the fovea and the superior perifovea.
In 22 eyes of 20 white donors (83.1 ± 7.7 years), SDD appeared as isolated or confluent drusenoid dollops punctuated
by tufts of retinal pigment epithelium apical processes and associated with photoreceptor perturbation, the researchers
noted. They detected subretinal drusenoid deposits and BlinD in 85 and 90% of non-neovascular AMD donors, respectively.
The study researchers observed that subretinal drusenoid deposit was thick (median, 9.4 µm) and more abundant in
the perifovea than in the fovea (p<0.0001). Additionally, BlinD was thin (median, 2.1 µm) and more abundant
in the fovea than in the perifovea (p<0.0001).
In conclusion, subretinal drusenoid deposits and BlinD prevalence in AMD eyes are high. Subretinal drusenoid deposits
organized morphology, topography and impact on surrounding photoreceptors imply specific processes of biogenesis.
Contrasting topographies of subretinal drusenoid deposits and BlinD suggest relationships with differentiable aspects of
rod and cone physiology, respectively. A two-lesion, two-compartment biogenesis model incorporating outer retinal
lipid homeostasis is presented.