Abstract
Abstract: :
Purpose: To investigate the effect of orally administered ruboxistaurin (LY333531), a selective protein kinase C ß inhibitor, on the permeability of the blood–retinal barrier in diabetic macular edema. Methods: Forty–one patients with diabetes and diabetic macular edema were randomly assigned to a randomized, placebo–controlled double–masked clinical trial including four study arms (ruboxistaurin 4mg/day, 16 mg/day, 32 mg/day, or placebo for 18 months). The ruboxistaurin group comprised 30 patients (42 eyes) and the placebo group 11 patients (13 eyes). Retinal vascular leakage was determined using vitreous fluorometry at baseline and at 3 months, 12 months, and 18 months during the trial. Statistical analysis of the effect of treatment accounted for repeated measurements, baseline permeability, explanatory variables including duration of treatment, baseline characteristics, etc. and possible interactions between variables. Results: Statistical analysis and modelling demonstrated a significant interaction between ruboxistaurin treatment at any dosage and baseline permeability (p= 0.032, mixed models), a two–fold or higher increase in retinal vascular leakage being associated with a significant reduction in leakage during the trial. Visual acuity was normal at baseline and remained unchanged throughout the study. Conclusions: In eyes with diabetic macular edema, ruboxistauin treatment was associated with a reduction of retinal vascular leakage in eyes with moderately to severely elevated baseline leakage, suggesting that the more severe the macular edema, the more readily detectable the clinical benefit from ruboxistaurin treatment may be.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled • diabetic retinopathy • macula/fovea