[Entoptic detection of choriocapillaris]

Entopic perception of the central choriocapillaris is documented by personal experience. Seen in this manner, the choriocapillaris appears due to circulatory conditions as a wavy convolute of fresh capillaries whose paths are paralleled by numerous, irregularly distributed, round, black structures. The latter have been presumed to be corpuscles, i.e. erythrocytes, and can be seen entopically as single rows of radial capillaries. Histological studies have shown, however, that these rows of erythrocytes are not always isolated; they have also been found in the choriocapillaris in clusters of rows. Moreover, analogously to the lack of entopic perception of erythrocytes in the retinal vessels in Purkinje's images, the erythrocytes of the choriocapillaris may likewise not be perceived for physical and optical reasons. Therefore the round, black formations are not entoptically perceivable erythrocytes of the choriocapillaries but can only originate in the circular network of the central choriocapillaris. Light directed experimentally into the eye and focussed on the choriocapillaris through a narrow slit positioned nasally leads via reflection to stimulation of the retina from outside to inside and so to entoptic perception of the choriocapillary network. Closer analysis of entoptic perception of the choriocapillaris is significant in view of its heuristic value.