Choroidal Neovascular Membranes Clinical Presentation

Updated: Mar 01, 2017
  • Author: Steve Charles, MD; Chief Editor: Andrew A Dahl, MD, FACS  more...
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Presentation

History

Patients with choroidal neovascular membranes (CNVMs) may report the following: [37, 38]

  • Decreased central vision
  • Central or paracentral, relative or absolute scotomas
  • Distortion (metamorphopsia)
  • Central light flashes or flickering
  • Impaired color vision
  • Prolonged recovery from light stress
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Physical

Perform an examination using a slit lamp biomicroscopy and a fundus contact lens or 60-, 78-, or 90-diopter (D) lens. Fluorescein angiography (FA) is required in some cases. ICG angiography is useful in approximately 5-10% of cases. Optical coherence tomography (OCT) has become an essential part in the assessment of these patients.

Clinical findings

Grey or ill-defined CNVMs can be subfoveal, juxtafoveal, extrafoveal, peripapillary, or even in the periphery. Experienced observers often visualize these lesions without OCT imaging or angiography, although imaging is necessary in virtually all instances. [39, 40] OCT imaging has largely replaced angiography.

Subretinal hemorrhage is common and frequently outlines the CNVM. In some cases, very large choroidal and/or subretinal hemorrhages occur that can be mistaken for malignant melanomas of the choroid.

Exudate, serous fluid, or both are often present with choroidal neovascularization (CNV). Angiographically well-defined membranes are referred to as classic; these lesions are usually subretinal. In many cases, the neovascular membrane is ill-defined and is termed occult; these lesions are usually under the retinal pigment epithelium (RPE) and often associated with a pigment epithelial detachment (PED). Retinal angiomatous proliferation (RAP) can be seen clinically; the neovascularization is now thought to arise from the choroid. Polypoidal choroidal vasculopathy is virtually impossible to identify clinically but can be accompanied by exudate, subretinal fluid, and hemorrhage. Large amounts of subretinal blood, fluid, or exudate may prevent clinical or angiographic visualization of the underlying CNV.

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Causes

AMD, POHS, myopia, trauma, angioid streaks, certain hereditary macular degenerations, and other causes of macular RPE damage have been associated with CNVM formation. Many cases are idiopathic.

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