ABSTRACT
As the retinal capillaries are too small to be resolved by normal fundus photography, microaneurysms are classically described as distinct small round objects, ranging from 10 µm to 100 µm in diameter. In color fundus images they appear red and in red-free images they appear dark. With fluorescein angiography microaneurysms are hyperfluorescent, thus appear as bright dots in positive images. In practice, the appearance of microaneurysms can deviate somewhat from the classical description. They may appear in association with larger vessels or as a conglomeration of more than one MA. Microaneurysms are difficult to distinguish from dot-hemorrhages in color retinal images. Dot-hemorrhages appear as bright red dots the size of a large microaneurysm and rarely exceed 200 µm in diameter. As the clinical implications
Detection of
of the presence of dot-hemorrhages and MAs are sufficiently similar there is usually no need for an automated MA detector to distinguish between them.
