Bilateral retinal vasculitis associated with clotting disorders

We found distinct alterations of the clotting and fibrinolytic mechanisms in a 27-year-old man who suffered from typical bilateral retinal vasculitis, clinically and fluoroangiographically manifest as obstruction of the central retinal veins. The partial thromboplastin time was slightly increased, a partial clot lysis occurred after one hour, the plasminogen level was markedly low, and alpha₂-macroglobulin was decreased, as were factor XII and IgG. Kallikrein was absent. Similar changes, though not so pronounced, were also found in the patient's son and in his brother.