Retinitis Pigmentosa. With an Analysis of 17 Cases Occurring in Deaf-Mutes

blood and urine analyses made by Dr. John M. Swan which are of interest, but which throw no fresh light on the cause or diagnosis of the disease. Retinitis Pigmentosa sine pigmento of which one frequently hears, the author regards as merely an early stage of the disease, and states that in such cases the pigments will appear sooner or later. The disease is so constantly bilateral that limitation of the disease appearances to one eye is presumptive evidence of its being due to chorioretinitis, probably syphilitic in origin, and not to congenital pigmentary degeneration. The statement is made that Macnamara found the disease " very prevalent among Hindus, with whom consanguineous marriages are strictly prohibited by religion. " It would be interesting to know whether Macnamara found the disease frequently uni-lateral or not. Such cases due to syphilis closely simulate true retinitis