Abstract
Abstract: :
Purpose: To confirm the efficacy of Doxium® (DX, calcium dobesilate) in reducing the blood–retinal barrier (BRB) permeability in patients with early diabetic retinopathy (DR). A relationship with HbA1c levels was also studied in this trial. Methods: Patients (aged 35–70) with type 2 diabetes and early DR were enrolled in this double–blind, placebo–controlled study conducted in 6 centres in Europe. Dosage was 2g/day of DX or placebo (PL) for 2 years. Posterior Vitreous Penetration Ratio (PVPR) evolution was assessed by vitreous fluorophotometry performed at 6–month intervals. Glucose and HbA1c levels were evaluated every 3 months. 194 patients (98 DX, 96 PL) were randomised and 168 included in Intent–To–Treat analysis for PVPR (86 DX, 82 PL). Patients were classified according to their mean HbA1c level during the study and PVPR analysis was performed globally and for each subgroup. HbA1c subgroups were defined as follows: HbA1c<7%, 7–9%, and ≥9% respectively. The statistical analyses were performed by Mann–Whitney or standard t–test for the 24–month values vs. baseline and by ANCOVA on the study period PVPR slopes. Results: Mean HbA1c levels between treatment groups were not different at baseline and during study duration (8.0% for DX, 8.2% for PL). PVPR of the different HbA1c subgroups at baseline was also similar between groups. Patients with HbA1c<7% under DX (n=27) showed a significant improvement of PVPR compared to PL (n=16) at 24 months (p=0.043 for difference with baseline). The subgroup with HbA1c between 7 and 9% (38 DX, 46 PL) showed statistically significant superiority of DX (p=0.050). Patients with HbA1c≥9% (21 DX, 20 PL) showed significantly different slopes (p=0.044, 95%CI –0.64 –0.01) with mean slopes –0.084 for DX and +0.241 for PL. Conclusions: Treatment with Doxium® 2g/day for 24 months versus PL shows a significant better result in the reduction of the BRB permeability in patients with early DR in the 3 HbA1c subgroups independently of blood glucose control.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • diabetes • diabetic retinopathy