Optical Coherence Tomography Angiography Insights in Choroidal Neovascular Membrane, Morphological Characteristics and Correlation With Structural Optical Coherence Tomography.

Choroidal neovascularization is an important path biologic mechanism encountered in a variety of chorio-retinal diseases. Choroidal neo-vascularization represents new blood vessel growth from the choroid that extends into the sub-retinal pigment epithelium, or sub-retinal space, or a combination of both. There is some evidence that the clinical findings and angiographic appearance of choroidal neo-vascular membrane correlate with the growth pattern. Choroidal neo- vascularization dynamic evolution includes initiation, inflammatory active, and inflammatory inactive stages.

It can be assumed that there is a risk of choroidal neo-vascular membrane development in any case where the integrity of Bruch's membrane or the retinal pigment epithelium is impaired. The most common cause of choroidal neo-vascular membrane is indisputably age-related macular degeneration, but choroidal neo-vascular membrane may also occur secondary to many other etiologies, such as pathological myopia, angioid streaks, uveitis, infection, and traumatic Bruch's membrane-retinal pigment epithelium defects, and idiopathic cases where no etiology can be detected.

Growth pattern:

Although no two choroidal neo-vascular membrane growth patterns are exactly alike, choroidal neo-vascular membrane grows in the plane between the retinal pigment epithelium and the Bruch membrane, between the retina and retinal pigment epithelium, or a combination of both (combined pattern). There is a retinal vascular contribution in approximately 6% of choroidal neo-vascular membrane . The new blood vessels are capillary-like and, with time, become arterial and venular.

Imaging modalities: