Histopathologic and ultrastructural findings of surgically excised choroidal neovascularization

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 thereafter 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] mu m vs 1498 [+/- 792] x 227 [+/- 166] mu m) 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.