Alterations in antithrombin III activity and other blood coagulation parameters after retinal detachment surgery

To evaluate perioperative changes in blood coagulation in patients undergoing retinal detachment surgery.

Prospective study of 56 patients, aged from 19 to 82 (mean +/- S.D. 53 +/- 16.8) years, undergoing retinal detachment surgery (encirclement with scleral buckling) under general anesthesia. Excluded were patients with venous or arterial disease and any other factors that could affect the parameters under consideration.

Blood was sampled from the cubital vein one day before surgery, immediately after induction of anesthesia but before surgery, immediately after completion of the operation but before the termination of anesthesia and on days 1 and 4 after the operation. We measured antithrombin III activity (AT III), platelet count, fibrinogen concentration, activated partial thromboplastin time (aPTT) and prothrombin time (PT).

Intraoperative AT III activity and platelet count were significantly lower, aPTT was shortened and PT prolonged, although all values remained within the normal range. These results indicate moderate activation of coagulation during retinal detachment surgery. On the first postoperative day coagulation activity was reduced, with increases in AT III activity, fibrinogen concentration and platelet count and prolongation of aPTT.

During retinal detachment surgery there is moderate activation of coagulation in the systemic circulation.