To establish whether the sub-RPE structures identified en face in RPE flatmount preparations are drusen with histopathological registration in serial sections.
In eyes with nonatrophic AMD, retinal sensitivity is correlated with the RPE + OS volume, but not the ONL volume or the area or volume of drusen.[Ophthalmic Surg Lasers Imaging Retina.2017;48:312-318.].
In particular, since CD5L is known to stimulate autophagy and to participate in oxidized LDL uptake in macrophages, we propose that anti-CD5L/AIM auto-antibodies may play a role in drusen biogenesis and inflammatory RPE damage in AMD.
Here, we use human induced pluripotent stem cell-retinal pigment epithelium (hiPSC-RPE) derived from patients with three dominant MDs, Sorsby's fundus dystrophy (SFD), Doyne honeycomb retinal dystrophy/malattia Leventinese (DHRD), and autosomal dominant radial drusen (ADRD), and demonstrate that dysfunction of RPE cells alone is sufficient for the initiation of sub-RPE lipoproteinaceous deposit (drusen) formation and extracellular matrix (ECM) alteration in these diseases.
OCT showed the large round drusen as focal or diffuse deposition of hyperreflective material between the RPE and Bruch membrane within the macula, determining focal dome-shaped or diffuse RPE elevation respectively, and the small radial drusen, which ranged from irregular slight thickening of the RPE/Bruch membrane complex to sawtooth RPE elevation.
The accumulation of damaged or postsynthetically modified proteins and dysregulation of inflammatory responses and angiogenesis in the retina/RPE are thought be etiologically related to formation of drusen and choroidal neovascularization (CNV), hallmarks of age-related macular degeneration (AMD).
We speculate that increased autophagy and the release of intracellular proteins via exosomes by the aged RPE may contribute to the formation of drusen.
Variants within CFH and LOC387715/HTRA1 may contribute to the increased risk of late AMD largely through their impact on precursors, such as drusen and/or other RPE/Bruch's membrane changes.