Homozygous and compound-heterozygous type I plasminogen deficiency is a common cause of ligneous conjunctivitis. - Schuster,V.; Zeitler,P.; Seregard,S.; Ozcelik,U.; Anadol,D.; Luchtman-Jones,L.; Meire,F.; Mingers,A.M.; Schambeck,C.; Kreth,H.W. (Thromb Haemost, 2001)