Abstract
Purpose :
To assess the inflammatory potential of drusen and subretinal drusenoid deposits (SDD), cells were documented by histology in the intraretinal, subretinal and sub retinal pigment epithelium (RPE)-basal lamina (BL) compartments in a single case of neovascular age-related macular degeneration (AMD).
Methods :
Two eyes of a white woman receiving numerous intravitreal anti-vascular endothelial growth factor injections for type 3 neovascularization secondary to AMD were prepared for high-resolution histology. Eye-tracked spectral-domain optical coherence tomography (OCT) imaging applied to the donor eyes linked in vivo imaging to histology. Cells (n=334) were counted on 199 glass slides. Cells with numerous RPE organelles were considered RPE-originated. Cells with sparse RPE organelles were considered non-RPE phagocytes, as were macrophages and giant cells.
Results :
Both eyes had centrally located soft drusen, most with calcific nodules, and abundant SDD. RPE-derived cells were common in the retina (n=125) and subretinal space (n=73); some corresponded to hyperreflective foci documented by in vivo OCT. In the same compartments, cells with sparse RPE organelles were infrequent (n=5 in both). The sub-RPE-BL space had many RPE-derived cells (n=87) and non-RPE phagocytes (n=49). The latter included macrophages and giant cells. Over drusen, RPE morphology smoothly transitioned from the adjacent layer up the sloping sides into the retina.
Conclusions :
Numerous sub-RPE-BL cells comport with a known role of inflammation in choroidal neovascularization and the presence of bioactive lipids in drusen and aged Bruch’s membrane. Most subretinal and intraretinal cells were RPE-derived and transdifferentiated; some manifest as hyperreflective foci. Comparing these compartments with regard to infiltrating non-RPE phagocytes, drusen are strongly associated with inflammatory cells while SDD is not. Due to processing-related retinal detachment in this case, this finding should be investigated in a larger clinical series, especially with high-resolution OCT technologies that resolves cells.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.