Objective: To determine whether lysing subretinal fibrin with tissue plasminogen activator (t-PA) before excising subfoveal choroidal neovascularization improves visual acuity in patients with age-related macular degeneration.
Design: Randomized, double-masked trial.
Participants: Eighty eyes of 80 patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration were studied.
Intervention: Each eye underwent pars plana vitrectomy and received a subretinal injection of t-PA or balanced salt solution (BSS) before the neovascular membrane was excised. Preoperative and postoperative protocol refraction, ophthalmic examination, color photography, and fluorescein angiography were performed in all 80 eyes.
Main outcome measures: Visual acuity and fluorescein angiographic evidence of leakage after 1 year.
Results: Visual acuity did not differ between the t-PA group (n = 40) and the BSS group (n = 40), and median best-corrected visual acuity was 20/320 for both groups (P = 0.38). Changes in visual acuity from baseline were also equal, with a median loss of 1 line in each group (P = 0.78). Patients whose initial visual acuity was 20/250 or less were more likely to improve by 2 or more lines (P = 0.01) and less likely to lose 2 or more lines (P < 0.001). Patients with choroidal neovascularization of at least 4 disc areas were more likely to improve by 2 or more lines (P = 0.02) and less likely to lose 2 or more lines (P < 0.001). After 1 year, choroidal neovascularization was present in seven of the t-PA eyes and in eight of the BSS eyes (P = 0.78).
Conclusions: With current surgical techniques, the use of t-PA before surgical excision of subfoveal choroidal neovascularization is of no visual or anatomic benefit to patients with age-related macular degeneration.