Intracameral concentrations of the fibrinolytic system components in patients with age-related macular degeneration

Abstract

To detect the intracameral concentrations and activities of plasminogen and other components of the fibrinolytic system, and to investigate whether those concentrations and activities are higher in patients with age-related macular degeneration (AMD) in comparison to healthy controls. Prospective case series of 93 patients scheduled for standard phacoemulsification. Mean plasminogen activity in patients with non-exsudative AMD (n = 24) revealed to be 0.06%N, in patients with exudative AMD (n = 7) 0.03%N and in healthy controls (n = 43) 0.02%N (p = 0.38, ANOVA). Plasminogen activator inhibitor I (PAI-1) was detected in neither group. Alpha2-antiplasmin activity was 1.61 U/ml in the non-exudative AMD group (n = 27), 0 U/ml in the exudative AMD group (n = 7) and 0.54 U/ml in the control group (n = 48) (p = 0.1, ANOVA). Concentrations of plasmin-a2-antiplasmin complex (PAP) were detected at levels of 17.91 ng/ml in the non-exudative AMD group (n = 11), of 16.6 ng/ml in the exudative AMD group (n = 5), and of 17.43 ng/ml in the control group (n = 14) (p = 0.92, ANOVA). Plasminogen is present with a very low activity in aqueous humor. There are no significant differences in aqueous humor concentrations or activities of plasminogen and other components of the fibrinolytic system between patients with non-exudative AMD, exudative AMD, and healthy controls. Further studies should investigate vitreous samples instead of aqueous humor samples. A careful and accurate workup of obtained intraocular fluids is needed to detect the low concentrations and activities of the parameters analyzed.