Clinicopathologic features of surgically excised choroidal neovascular membranes

The purpose of this study is a descriptive correlation of the clinical, fluorescein angiographic, and pathologic features in a large series of patients who underwent surgical removal of choroidal neovascular membranes.

The patients' clinical data were recorded for each surgically removed choroidal neovascular membrane received in the authors' laboratory. Fluorescein angiographic characteristics of the membranes, including well-demarcated versus poorly demarcated preoperative appearance, postoperative choroidal atrophy, and membrane recurrence, were recorded whenever possible. The pathologic features of the membranes, including cellular and extracellular constituents, were determined on light and electron microscopic examination.

A total of 123 membranes were studied. Underlying diseases in decreasing order of frequency were age-related macular degeneration, ocular histoplasmosis syndrome, myopia, idiopathic and pattern dystrophy. The cellular and extracellular constituents of the membranes were similar, regardless of underlying disease, with the exception of basal laminar deposit, seen almost exclusively in age-related macular degeneration. Well-demarcated membrane components were localized with a central subretinal pigment epithelium fibrovascular core. Poorly demarcated membranes were represented by a subneurosensory retinal (breakthrough) component, although most of these membranes had associated retinal pigment epithelium. Fragments of Bruch's membrane were common in specimens from patients with postoperative choroidal atrophy, and there was generally a lack of vascular channels in membranes that led to recurrence.

This study suggests that choroidal neovascular membranes represent a stereotypic, nonspecific response, regardless of underlying disease. Most membranes are subretinal pigment epithelium, and what is recognized angiographically as a subneurosensory retinal component contains associated retinal pigment epithelium in most instances. Fragments of Bruch's membrane in the specimen correlate with postoperative choroidal atrophy. Lack of vascular channels in the surgical specimen may correlate with a risk for postoperative membrane recurrence.