THE PLACE OF COATS'S DISEASE AMONG THE DISEASES OF THE RETINA

Abstract

The place of Coats's disease, called by Coats retinitis exsudativa (retinitis externa hemorrhagica), among the diseases of the retina is still an uncertain one. The difficulty of characterizing it as a distinct entity is due to the fact that the massive exudations which are characteristic of the disease occur also in the other well characterized diseases of the retina, such as disciform macular degeneration (Junius and Kuhnt) and angiomatosis of the retina (von Hippel), and with extensive retinal hemorrhages of any origin. The difficulty is still heightened by the differences of opinion among investigators as to the cause of the exudations. Coats himself considered them to be the result of the hemorrhages in the retina. He was in doubt about the origin of the hemorrhages but leaned toward the idea that they are the result of some change in the small vessels. Other investigators, following Leber's lead,1considered Coats's