[A method and a device for the differential diagnosis of retinal pathological states]

A new method and a device--a stimulator ophthalmological KNSO 1-88 "Phosphene" is suggested for differential diagnosis of pathologic conditions of the retina. It is shown that by means of the proposed method, after 20-25 minutes of dark adaptation the threshold of electric sensitivity by phosphene increases differently with respect to the initial level (on the first minute of dark adaptation): in norm--by 15.2%, in optic nerve atrophy--by 14%, in pigmentary and nonpigmentary forms of retinal dystrophy--by 33.2%. Thus, investigation of the threshold of electric sensitivity by phosphene presents valuable supplementary data for differential diagnosis between optic nerve atrophy and nonpigmentary form of retinal degeneration: in optic nerve atrophy the degree of the threshold increase of absolute electric sensitivity differs, as a rule, but a little from normal values, while in pigmentary and nonpigmentary forms of retinal degeneration it is 2-3 time above norm.