Electron microscopic studies on retinochoroidal atrophy in the human eye.

Nine eyeballs were enucleated from nine patients with excessive myopia, secondary retinochoroidal atrophy, absolute glaucoma, uveal malignant melanoma, Behçet's disease and sympathetic ophthalmia. The retina and choroid were studied with light and electron microscopes. The results were: In excessive myopia, marked blockade of choriocapillaries was accompanied by progressive retinal degeneration. In secondary retinochoroidal atrophy induced by retrobulbar fibrosis, the choriocapillaries were partially blocked and the retina had markedly degenerated. In Behçet's disease, exudative inflammation was recognized in the choroid extending to the retina and causing retinal detachment, though the choriocapillaries remained morphologically normal. In sympathetic ophthalmia, both the choriocapillaries and the retina remained normal, though marked inflammation was recognized in the outer layer of the choroid. In absolute glaucoma, the fine structures of the choriocapillary were well preserved in spite of bulbar hypertonia. In uveal malignant melanoma, the ultra structure of the choriocapillary near the tumor was well preserved. The choriocapillaries were normal even when the retina had degenerated. Retinal degeneration was recognized when changes such as blockage, disappearance, dilatation and increased permeability were found in the choriocapillaries. Damage to the choriocapillaries might play an important role in inducing and developing retinochoroidal atrophy.