thromboplastin and Retinal-Diseases

Intravitreal anti-VEGF (anti-vascular endothelial growth factor) biologics have revolutionized the pharmacological management of chorioretinal diseases. However, the systemic adverse events such as stroke or bleeding are the concerns for many patients and physicians. The mechanism to develop these side effects are poorly understood. Consecutive 95 patients with retinal diseases were studied for their blood activated partial thromboplastin time (APTT), prothrombin time (PT), international normalized ratio (INR), and concentration of fibrinogen before and after intravitreal conbercept. Additionally, plasma nitric oxide (NO) and endothelin-1 (ET-1) were investigated on 38 of the 95 patients. Compared with the pre-injection, 4-week post-injection values of APTT and PT were increased by 0.582 s (p = 0.038, paired t test) and by 0.086 s (p = 0.080, paired t test; p = 0.0475, Sign test), respectively. At the same time, fibrinogen decreased by 0.048 g/L. Plasma levels of NO or ET-1 or VEGF did not significantly change from pre-injection levels. Our findings advanced the understanding of mechanism for systemic side effects associated with intravitreal anti-VEGF and emphasized paying more attention to higher risk of possible bleedings for patients following intravitreal conbercept.

Topics: Aged; Blood Coagulation; Endothelin-1; Female; Fibrinogen; Humans; Intravitreal Injections; Male; Middle Aged; Nitric Oxide; Prothrombin; Recombinant Fusion Proteins; Retinal Diseases; Thromboplastin

We found distinct alterations of the clotting and fibrinolytic mechanisms in a 27-year-old man who suffered from typical bilateral 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.

Topics: Adult; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Child, Preschool; Clot Retraction; Edema; Factor XII; Fluorescein Angiography; Humans; Immunoglobulin G; Macroglobulins; Male; Papilledema; Plasminogen; Retinal Diseases; Retinal Hemorrhage; Thromboplastin; Vasculitis