The Use of the Roth-Keeler Central Field Scotometer in the Study of Diabetic Retinopathy

Abstract

Central field scotometry has been carried out at 4-week intervals for a period of 4 months on 27 diabetic subjects, 16 without ophthalmoscopically visible retinopathy, and 11 with varying degrees of retinopathy. Scotomata were found to be present in 5 of the 16 (31%) retinopathy-free subjects. These scotomata were transient and were observed during only 5 of the 108 (4.6%) examinations. The scotomata in the patients with retinopathy were also shown to be transient in nature and did not necessarily occur in areas of the retina in which visible pathological changes were apparent. These results give support to the view that pathological changes occur in the retina before the onset of overt retinopathy.