Light and electron microscopy and trypsin digestion were carried out on the retina of a 50-year-old woman with known hemoglobin SC disease. Retinal vascular occlusions were thought to be the initiating event in the histopathogenesis of her SC retinopathy. The occlusions occurred in the equatorial region of the retina, in the area where proliferative retinopathy subsequently developed. The distal portions of the retinal vessels were completely occluded. Fat emboli found in multiple retinal vessels were thought to be a terminal event and not to contribute to the development of the retinopathy. No fat was found in retinal blood vessels anterior to the erythrocyte-containing area (anterior to midway between the equator and ora serrata), showing that there was no blood flow through that anterior (distal) part of the retinal blood vessels.
Eagle RC, Yanoff M, Fine BS. Hemoglobin SC Retinopathy and Fat Emboli to the EyeA Light and Electron Microscopical Study. Arch Ophthalmol. 1974;92(1):28–32. doi:10.1001/archopht.1974.01010010032008