Purpose
The diabetic macular edema (DME) is the most common cause of central visual loss in diabetic patients. Intravitreal injections (IVT) of ranibizumab have been approved for the treatment of DME. However, around 10 ranibizumab IVTs are needed during the first year of treatment with ranibizumab alone (RESOLVE study). In this context, ranibizumab IVTs combined with macular laser may be beneficial to reduce the number of IVT. The aim of this study was to evaluate the efficacy of IVT associated with deferred laser grid for diabetic macular edema. The primary endpoint was the number of reinjections, the best-corrected visual acuity (BCVA) and the central retinal thickness (CRT) measured at one year, of a strategy based on intravitreal ranibizumab injection associated with laser treatment in DME.
Methods
Prospective, monocentric open-label, uncontrolled phase 2 study. 15 eyes of 13 patients with BCVA ≤ 69 letters and CRT ≥ 310μ (OCT Cirrus Zeiss) due to DME were enrolled between October 2011 and October 2012. Patients were treated with ranibizumab 0.5 mg given for 3 months then with laser grid at month 4. During follow-up, a ranibizumab injection was performed every 2 months in case of BCVA decreased more than 5 letters. Each patient in the study underwent VA measurement on the Early Treatment Diabetic Retinopathy Study chart (ETDRS), spectral domain-OCT, quality of life scale, glycated hemoglobin (HbA1c) measurement, fluorescein angiography, and multifocal electroretinogram at baseline and during their follow-up.
Results
The mean age of the subjects was 62 years old. At baseline, their characteristics were (expressed as mean): duration of diabetes: 15 years, HbA1c: 7,4%, VA: 53 letters (20/100 snellen equivalent), CRT: 479μ. From baseline at 6 months, there is a mean gain of 12.6 letters of BCVA (p = 0.014). The decrease in the average CRT is 76.7μ (p = 0.013). 37.5% of patients required a new IVT at 6 months. No endophthalmitis cases occurred.
Conclusions
Adding macular grid to ranibizumab IVT appears promising in the treatment of DME. It seems to reduce the number of IVTs and consequently the economic burden of the treatment. A total of 30 patients included and a follow up of one year will refine these results.
Keywords: 505 edema •
688 retina •
498 diabetes