Kinetics of Retinal Lipoprotein Precipitation and Elimination after Closure of Subretinal New Vessels

Abstract

Photodynamic therapy for subfoveal new vessels may be associated with retinal precipitation of lipoprotein, presumably because early extraction of water and salts from the subretinal fluid increases the concentration of leaked plasma proteins. Despite reperfusion of the subretinal vessels, macromolecular leakage appears to cease within 100 days, indicating that functional maturation of the new vessels has occurred, with an associated decrease in pore size.

The Pearl Necklace Sign

“…Resorption of the precipitates may then be dependent on phagocytosis. 26 We confirm that the hyperreflective dots of the pearl necklace sign seem to be another form of lipid deposition that co-exist with larger aggregated hard exudate deposition noted on SD-OCT, in the same retinal layer (Figures 3 and 4). Histopathologic reports have documented that hard exudates, stained with oil red-O, are also predominantly located in the outer retinal layers adjacent to the deep capillary plexus.…”

Multilayered Pigment Epithelial Detachment in Neovascular Age-Related Macular Degeneration

“…Kinetic considerations suggest that fibrinous exudation from the overlying CNV complex may precipitate onto the surface of Bruch's membrane, whereas the lower density fluid components are filtered out. 14 The remaining fibrin may serve as a scaffolding matrix for blood vessel in-growth and connective tissue formation. Various histopathologic studies have shown that CNV is associated with not only neovascular ingrowth but also inflammatory cells, fibroblasts, myofibroblasts, glial cells, and RPE cells, which in chronic lesions become oriented in layers of fibrous tissue separated by clefts of lesser density.…”

Treatment of choroidal neovascularization using intravitreal bevacizumab

“…Effective closure of a source of retinal leakage may be followed shortly afterwards by increased amounts of hard exudate, presumably as a result of precipitation following early extraction of water and salt whereby slowly resorbed high-molecular weight components increase in concentration and precipitate in the extracellular space of the retina (Christoffersen et al 1998;Taarnhoj et al 2003). It has to be considered, however, that several patients had mainly extrafoveal disease activity (their subfoveal CNV component had involuted to some extent) and that several had suffered considerable delay between their first contact with a physician and the initiation of treatment.…”