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Updated: Sep 22, 2026
An Ex Vivo Choroid Sprouting Assay of Ocular Microvascular Angiogenesis
Published on: August 6, 2020
Histopathologic and ultrastructural findings of surgically excised choroidal neovascularization. Submacular Surgery
1Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA.
Objective:
To study the histologic and ultrastructural features of surgically excised choroidal neovascularization (CNV) from patients who had undergone submacular surgery.
Materials And Methods:
Voluntarily submitted surgically excised CNV specimens from a subset of specimens obtained by the Submacular Surgery Trials Research Group between January 1, 1994, and December 31, 1996, were available for this study. The specimens were routinely processed for transmission electron microscopic examination. The largest horizontal and vertical dimensions, cellular and extracellular constituents, and relationship of the CNV to the neurosensory retina and retinal pigment epithelium (RPE) were recorded.
Results:
Seventy-eight surgical specimens were obtained from 160 patients treated surgically in Submacular Surgery Trials centers. Sixty-one (78%) were from patients with age-related macular degeneration (ARMD) and 17 (22%) were from patients with ocular histoplasmosis syndrome or idiopathic causes (hereafter referred to as the non-ARMD group). The histologic diagnosis was fibrovascular tissue, fibrocellular tissue, or hemorrhage in all cases. Vascular endothelium and RPE were the most common constituents of the CNV. Basal laminar deposit was only present in CNV from patients with ARMD. Age-related macular degeneration specimens were larger (mean +/- SD, 2042 [+/- 1175] x 320 [+/- 185] microm vs 1498 [+/- 792] x 227 [+/- 166] microm) and were more likely to have a sub-RPE (beneath the RPE) component than non-ARMD specimens.
Conclusions:
All evaluated surgically excised CNV specimens in this study from patients enrolled in the Submacular Surgery Trials consisted of fibrovascular tissue, fibrocellular tissue, or hemorrhage. Surgically excised CNV associated with ARMD in this series was larger and often was located beneath the RPE compared with non-ARMD CNV, although fewer than half of all the specimens could be oriented by topographic relationship to the RPE.
Insights
This study examined surgically removed choroidal neovascularization (CNV) tissue. CNV from age-related macular degeneration (ARMD) was larger and often located beneath the retinal pigment epithelium (RPE) compared to other causes.
Area of Science:
- Ophthalmology
- Histopathology
- Electron Microscopy
Background:
- Choroidal neovascularization (CNV) is a key feature of several blinding retinal diseases.
- Submacular surgery is a treatment option for specific types of CNV.
- Understanding the histologic and ultrastructural characteristics of excised CNV is crucial for disease insight.
Purpose of the Study:
- To investigate the histologic and ultrastructural features of surgically excised choroidal neovascularization (CNV).
- To compare CNV characteristics between patients with age-related macular degeneration (ARMD) and other causes.
Main Methods:
- Transmission electron microscopy was used to examine 78 surgically excised CNV specimens.
- Specimens were obtained from patients in the Submacular Surgery Trials (1994-1996).
- Histologic diagnosis, cellular/extracellular constituents, and spatial relationship to retinal layers were analyzed.
Main Results:
- All specimens comprised fibrovascular tissue, fibrocellular tissue, or hemorrhage.
- Vascular endothelium and retinal pigment epithelium (RPE) were common constituents.
- CNV from ARMD patients (61 specimens) was larger and more likely to have a sub-RPE component than non-ARMD specimens (17 cases).
- Basal laminar deposit was exclusively observed in ARMD-associated CNV.
Conclusions:
- Surgically excised CNV consists of fibrovascular or fibrocellular tissue, or hemorrhage.
- ARMD-related CNV exhibits distinct features, including larger size and sub-RPE location, compared to non-ARMD CNV.
