Clinicopathologic Correlation of Aneurysmal Type 1 Neovascularization in Age-Related Macular Degeneration

To correlate multimodal retinal imaging with high-resolution epoxy resin histologic analysis aligned to in vivo tomograms in a patient with exudative aneurysmal type 1 (AT1) neovascularization and hemorrhage secondary to age-related macular degeneration (AMD).

Case study and clinicopathologic correlation.

An 84-year-old man of European descent with AT1 neovascularization secondary to AMD with a 6-year follow-up with combined antiangiogenic and photodynamic therapy.

Multimodal imaging from each clinic visit, including fluorescein angiography, indocyanine green angiography, and OCT, was correlated with ex vivo OCT and high-resolution histologic images of the donor eye, aligned to the en face images showing hemorrhage and exudation.

Location of the branching vascular network and the aneurysmal vascular dilations in angiography, correlated with histologic findings.

Clinically, a hemorrhagic detachment of the retinal pigment epithelium (RPE) in the macular area was associated with an AT1 neovascularization extending near the optic nerve head, where the choroid, which was thin overall, was extremely thin. Resolution of the hemorrhage accompanied by progressive macular atrophy and internal changes in the reflectivity of the RPE detachment were observed. Histologic analysis suggested a physical continuity from a hyalinized choroidal artery to a capillary bed (branching vascular network) in the sub-RPE-basal lamina (BL) space without visualization of aneurysmal dilations.

Clinicopathologic correlation of AT1 neovascularization from an intact treated eye with dye-based angiographic and OCT scans supports the proposed nomenclature of AT1 neovascularization over polypoidal choroidal vasculopathy. We described continuity of the sub-RPE-BL branching vascular network with choroidal arteries and histologic correlates of common OCT signatures of neovascular AMD. The thinness of choroid in this patient of European descent contrasts with that reported for Asian populations, in which AT1 neovascularization is associated commonly with pachychoroid disease characteristics. This case reinforces the different manifestations of AT1 neovascularization across and within diverse ethnicities and diseases.