Autologous plasmin enzyme in the surgical management of diabetic retinopathy

PURPOSE: This is a pilot study to assess the use of autologous plasmin enzyme (APE) as an adjunct to vitreous surgery in eyes with advanced diabetic retinopathy. DESIGN: Prospective noncomparative interventional case series. PARTICIPANTS: Seven patients with advanced diabetic retinopathy selected at random from our practice population. METHODS: Seven eyes were treated with APE as an adjunct to standard vitreous surgery. Six eyes had macular tractional retinal detachments, and one eye had refractory macular edema. Three fellow eyes had standard vitreous surgery performed for macular tractional retinal detachments without APE. All 10 eyes had macular edema and background diabetic retinopathy. MAIN OUTCOME MEASURES: The main outcome measures included induction of a posterior vitreous detachment, retinal reattachment, improvement in visual acuity, and resolution of macular edema. RESULTS: All seven APE-treated eyes achieved spontaneous or easy removal of the posterior hyaloid including one eye that had vitreoschisis over areas of detached retina. All eyes treated with APE had resolution of intraretinal edema. Retinas of all eyes treated with APE were reattached. The three fellow eyes were treated by vitreous surgery without APE. Two of the three fellow eyes had reattached retinas, but none had resolution of intraretinal edema without further focal photocoagulation treatment. Mean visual acuity improvement was 0.7 logarithm of the minimum angle of resolution (LogMAR) units in APE-treated eyes and 0.1 LogMAR units in eyes without APE. The average follow-up period was 14 months. CONCLUSIONS: This pilot study suggests that APE may be beneficial in the surgical management of diabetic retinopathy.