[Diagnostic value of pseudoprotanomaly for the differential diagnosis between retinal and optic nerve diseases]

It has been known since the time of Koellner that some diseases of the retina produce a shift of the Rayleigh equation toward red on the anomaloscope. In 1951, at the suggestion of Engelking, this "pseudoprotanomaly" was analyzed using Helmholtz's color mixer at Heidelberg University Eye Clinic. Pseudoprotanomaly is pathognomonic for diseases accompanied by macular edema (central serous chorioretinitis) as well as for the early stage of Stargardt's macular degeneration. The various hypotheses regarding its origin are discussed. In cases of visual disturbance with just-recognizable scotoma, ophthalmoscopy does not permit a definite differential diagnosis between retrobulbar neuritis and a macular lesion. In these cases "pseudoprotanomaly" is a definite sign that there is a macular lesion and not a retrobulbar neuritis.