Tissue plasminogen activator (tPA), urokinase, and streptokinase are all fibrinolytic agents. tPA is a naturally occurring serine protease with a molecular mass of 68 kD. Because tPA is normally present at a higher concentration in the aqueous humor of the human eye than in blood, it is less toxic to ocular tissues than other fibrinolytic agents and is specific for dissolution of fibrin clots. tPA has been used successfully to resolve fibrin clots after intraocular surgery, vitrectomy, keratoplasty, glaucoma filtering procedures, and sub-retinal hemorrhage due to choroidal neovascularization. These drugs are not approved by the FDA for ocular use and are therefore used off-label.
Chang W, Garg SJ, Maturi R, et al. Management of thick submacular hemorrhage with sub-retinal tissue plasminogen activator and pneumatic displacement for age-related macular degeneration. Am J Ophthalmol. 2014;157(6):1250–1257.
Dotan A, Kaiserman I, Kremer I, Ehrlich R, Bahar I. Intracameral recombinant tissue plasminogen activator (r-tPA) for refractory toxic anterior segment syndrome. Br J Ophthalmol. 2014;98(2):252–255.
Zalta AH, Sweeney CP, Zalta AK, Kaufman AH. Intracameral tissue plasminogen activator use in a large series of eyes with valved glaucoma drainage implants. Arch Ophthalmol. 2002;120(11):1487–1493.
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.