Purpose
To investigate angiographic changes in retinal perfusion during the course of treatment with repeated intravitreal ranibizumab injections in patients with diabetic macular edema.
Methods
Subanalysis of biannually performed fluorescence angiography (FA) in patients of the RESTORE study. Patients with visual impairment due to diabetic macular edema were included in this prospective, multicenter clinical trial and randomized to 3 treatment arms: 0.5 mg intravitreal ranibizumab monotherapy (RT), 0.5 mg intravitreal ranibizumab combined with macular laser (CT) or laser therapy only (LT). After a loading dose of 3 monthly ranibizumab injections or baseline laser therapy respectively patients were treated following predefined retreatment criteria (PRN). Biannually acquired FA images were graded by certified readers of the Vienna Reading Center: The innermost capillaries around the fovea were outlined manually and the area was calculated defining the foveal avascular zone (FAZ). Changes in size and formation of the FAZ as well as capillary drop out at the macula were followed over the period of treatment to assess treatment dependent effects on macular perfusion within and between treatment arms.
Results
Three hundred forty five diabetic patients were included in this clinical trial. At baseline, the FAZ configuration was severely or completely destroyed in 17 % of patients (RT=18 %,, CT=17 %, LT=17%). A parafoveal capillary dropout was found in 3% of patients (RT=3 %,, CT=3 %, LT=2%). After 12 months, the FAZ configuration was severely or completely destroyed in 9% of patients (RT=10 %,, CT=11 %, LT=5%) and parafoveal capillary dropout was found in only 1% of patients (RT=1 %,, CT=1 %, LT=1%).
Conclusions
Within 12 months no progression of central microangiopathy and non-perfusion was found in diabetic patients receiving prolonged and repeated anti VEGF therapy.
Keywords: 499 diabetic retinopathy •
572 ischemia •
550 imaging/image analysis: clinical