What differentiates Type 2 CNV from other types?

Type 2 choroidal neovascularization (CNV) is characterized by its specific anatomical location, which is primarily found underneath the retinal pigment epithelium (RPE). This positioning is significant because it contrasts with other types of CNV, such as Type 1, where the neovascularization occurs below the RPE and intrudes into the subretinal space.

Understanding this distinction is crucial for diagnosis and management because the location of the CNV can influence visual prognosis and treatment strategies. The abnormal blood vessels in Type 2 CNV typically arise from the choroid, penetrate the RPE, and can lead to serous retinal detachment and associated complications.

The other attributes mentioned in the choices, such as the presence of bleed, association with photoreceptors, and underlying atrophic changes, can be associated with CNV in general but do not specifically define Type 2 CNV. These factors might be relevant to various presentations of CNV but do not provide the defining characteristic that the location does. The understanding of these locations is essential for clinicians when determining the nature of the CNV and planning appropriate interventions.