A description of investigations carried out in the equatorial province of the Anglo-Egyptian Sudan on a hitherto undescribed disease of the eyes now known as "Sudan blindness"; together with an account of the manifestations of onchocerca volvulus (Leuckart.1893), notes on that parasite, and its relation to "Sudan blindness"

Abstract

(1) An endemic disease causing blindness in the Bahr-el-Ghazal Province of the Anglo-Egyptian Sudan is described. The disease has become epidemic within the last 5 to 10 years.(2) The disease is local and found along the banks of rocky streams, geographically its distribution being identical with that of Onchocerca volvulus.(3) Clinically the condition known as Sudan blindness gives the ophthalmo­scopic appearance of a diffuse retino-choroiditis with optic atrophy, often with sclerosis of the retinal vessels and the deposition of masses of pigment on the retina.(4) Pathologically the retina shows an atrophy of the cellular layers, irregular in its distribution, and the passage of pigment forward until it lies in masses on, instead of beneath, the retina. Perivascular reaction, so characteristic of oncho- cercal keratitis, is not present, and the cornea is not vascularised as in keratitis, but there is considerable vascularisation of the retina. Optic atrophy is almost certainly present.(5) Onchocerca volvulus is recorded for the first time from the Sudan with its various manifestations, including punctate keratitis(6) Sudan blindness is believed to be due to O. volvulus