Light and electron microscopic studies on human retinal blood vessels of patients with sclerosis and hypertension

To correlate the ophthalmoscopic and histological findings on human retinal blood vessels of patients with sclerosis and hypertension, respectively.

Ophthalmoscopy, light microscopy, and transmission and scanning electron microscopy with histochemical staining were performed on eyes obtained from patients with a malignant orbital tumor, with absolute glaucoma, or with hypertensive retinopathy.

The retinal arteries in aged patients with ophthalmoscopic sclerotic blood vessels had walls in which the smooth muscle cells had been replaced by collagen fibers, proteoglycan filaments, and ruthenium red-positive materials. The venous blood columns were hidden by numerous swollen nerve fibers and extending Müller cell processes. In a patient with accelerated hypertensive retinopathy, some of the muscle cells in the arteriolar walls were edematous. Focal and generalized narrowing of the retinal arteries appeared to be caused by a true functional constriction of the smooth muscle cells in the walls.

The ophthalmoscopic signs, such as reflection of the retinal arterial blood column and crossing phenomena, were supported by sclerotic manifestations clearly visible upon histological examination. There were some organic changes in the retinal arteries in a patient with accelerated hypertensive retinopathy, but the ophthalmoscopic narrowings appeared to result from a functional constriction of the smooth muscle cells in these vessels.