The following is a summary of the “Towards a better understanding of non-exudative choroidal and macular neovascularization,” published in the Jan 2023 issue of Progress in retinal and eye research by Sacconi, et al.

Treatment-naive type 1 neovascularization without signs of exudation is typically meant when people talk about non-exudative macular and choroidal neovascularization (MNV and CNV). Although non-exudative MNV was first identified in the early 1970s through histopathological studies, indocyanine green angiography in the late 1990s provided the first clinical report of this finding in eyes with age-related macular degeneration (AMD). 

Improved retinal imaging has led to a greater understanding of the role that non-exudative MNV plays in age-related macular degeneration and the role that CNV plays in other macular disorders. However, there needs to be more agreement on how to precisely define this entity or how to best treat it clinically. In addition, there may be a spectrum of diseases, as evidenced by differences in imaging features and clinical course. Here, they take stock of the vast literature accrued over the past decade to advance their knowledge of MNV and CNV that do not involve exudative mechanisms.

Key insights into this phenomenon are revealed through discussions of its frequency, multimodal imaging characteristics, clinical course, and therapeutic response. This review also proposes a new theory about the etiology and progression of various sub-types of non-exudative MNV/CNV, which may have different aetiologies and pathways depending on the clinical context of the disease, in light of these observations.