Abstract
Purpose::
To asses the durability of Ranibizumab treatment effect in patients with diabetic macular edema (DME).
Methods::
Twenty patients with refractory DME were given intraocular injections of 0.5 mg of Ranibizumab at baseline, month 1, 2, 4, and 6. Primary outcome measure was change in visual acuity (VA, ETDRS letters read) between baseline and 7 months and secondary outcomes were change from baseline in foveal thickness (FT) and macular volume (MV) by optical coherence tomography (OCT). Durability of the effect was assessed between 7 and 12 months.
Results::
Fifteen of 20 patients enrolled have completed 12 months of follow up. Only one patient received additional treatment, an intraocular injection of Bevacizamab at month 10 due to an increase in FT of 110 µm from the primary endpoint (no change in VA). The median change in VA from baseline for the other 14 patients at 12 months (6 months after the last injection) was 7 ETDRS letters, compared to 9 ETDRS letters at one month after the last injection. The median improvement at 12 months in FT and MV were 187 µm and 2 mm3 compared to 258 µm and 3 mm3 at one month after the last injection. Compared to baseline, median excess FT at 12 months was reduced by 71% and excess MV was reduced by 52%.
Conclusions::
Five injections of 0.5 mg of Ranibizumab over 6 months resulted in significant improvement in VA, FT, and MV. During the subsequent 6 months after the last injection 1 of 15 patients required an injection of Bevacizumab and the other 14 patients showed surprising stability of vision and a modest increase in FT. Since recurrence of FT appears to precede drop in VA, it would be reasonable to design future trials with an initial aggressive treatment phase followed by a phase of "as needed" treatment based upon recurrence of FT.
Clinical Trial::
www.clinicaltrials.gov Pending
Keywords: retina • edema • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials