[The operative treatment of nystagmus-caused variable squint angles with Cüppers "Fadenoperation" (author's transl)].

THE "Fadenoperation" developed by Cüppers is described. With this, the arc of contact is changed with retension of the anatomical insertion. It is indicated when an innervational factor is to be influenced, especially by the treatment of an instable squint angle caused by nystagmus. A differentiation between a static and dynamic angle must be made. Only the static angle can be corrected by common recession and resection. The dynamic angle can be corrected by the "Fadenoperation" described by Cüppers. The difficulty in recognizing the nystagmus and determining the width of the static and dynamic angle is described in detail. Satisfying results were attained, following these criteria, shown by 19 (76%) of the operated convergent squinters with an instable angle.