Antifibrinolytic drugs, such as ε-aminocaproic acid and tranexamic acid, inhibit the activation of plasminogen. These medications may be used systemically to treat patients with hemorrhage secondary to excessive fibrinolysis and to prevent recurrent hyphema, which most commonly occurs 2–6 days after the original hemorrhage. These agents are contraindicated in the presence of active intravascular clotting, such as diffuse intravascular coagulation, because they can increase the risk of thrombosis. They should not be used in pregnant patients, in patients with coagulopathies or who are receiving platelet inhibition therapy, or in patients with renal or hepatic disease. Patients with larger hyphemas and those with delayed presentation are at high risk of rebleeding, but patients with early presentation and those with smaller hyphemas are at low risk of rebleeding. ε-Aminocaproic acid is usually reserved for patients at higher risk of rebleeding.
ε-Aminocaproic acid is used in a dosage of 50–100 mg/kg every 4 hours, up to 30 g daily. Possible adverse reactions include nausea, vomiting, muscle cramps, conjunctival suffusion, nasal congestion, headache, rash, pruritus, dyspnea, tonic toxic confusional states, cardiac arrhythmias, and systemic hypotension. Gastrointestinal adverse effects are similar with doses of either 50 or 100 mg/kg. The drug should be continued for a full 5–6 days to achieve maximal clinical effectiveness. Topical ε-aminocaproic acid may be an attractive alternative to systemic delivery in the treatment of traumatic hyphema, but the efficacy of topical treatment has been questioned. Optimal topical concentration to maximize aqueous levels and minimize corneal epithelial toxicity is 30% ε-aminocaproic acid in 2% carboxypolymethylene.
Tranexamic acid is used off-label to reduce the incidence of rebleeding after traumatic hyphema. It is 10 times more potent in vitro than ε-aminocaproic acid. The usual dosage is 25 mg/kg of tranexamic acid 3 times daily for 3–5 days. Gastrointestinal adverse effects are rare.
Karkhaneh R, Naeeni M, Chams H, Abdollahi M, Mansouri MR. Topical aminocaproic acid to prevent rebleeding in cases of traumatic hyphema. Eur J Ophthalmol. 2003;13(1):57–61.
Excerpted from BCSC 2020-2021 series: Section 2 - Fundamentals and Principles of Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.