[The immunodiagnosis of diabetic retinopathy]

Detection of antibody to S antigen in the lacrimal fluid is one of the earliest preclinical signs of retinal involvement in diabetes mellitus. The prognostic levels of S antigen in the passive hemagglutination test have been determined: protective levels, 1:16-1:64, promoting a prolonged intactness of the retina; autoallergic (1:128 and higher) and immunodeficient ones (1:16), characteristic of various pathogenetic groups of diabetic retinopathy.