Morphological studies of the choriocapillaries and pigment epithelium of the eye after acute blood loss.

Albino mice were bled through the hearts and 1/3 ml of blood withdrawn from each animal. The choriocapillaries and the pigment epithelia of the eyes were selected for observations using the electron microscope. Morphological changes were apparent during the first 72 h after bleeding. Increase of vesicles in both the endothelial cells and the basal infoldings of pigment cells were features. Thickening of basal infoldings, thinning out of Bruch's membrane (with decrease content of fibrillary substances) as well as a transient disappearance of the diaphragms of pores of endothelial cells were also observed. Trypan blue dye was also found to have diffused into the retina in the first 24 h after bleeding. These processes appeared to augment the decreased nutrient supply to the retina after blood loss.