Materials and Methods: 53 eyes of 37 patients with macular edema secondary to diabetic retinopathy were treated with 0.5 mg intravitreal ranibizumab injections and enrolled in the study. These patients were evaluated with LogMAR visual acuity, biomicroscopy, optical coherence tomography results including central subfield thickness and ISOS/ELM injury, age, gender, diabetes mellitus type, treatment and chronicty, follow up time, number of injections, injection algorithm, type of macular edema, peripheral ischemia on fluorescein angiography (FA).

Results: Mean follow-up was 12.7±8.3 months. The mean logMAR visual acuity and central subfield thickness were 0.74±0.77 and 425.6±186 μm before injections and 0.66±0.65 and 332 ±154 μm after the injections. Macular edema types were 41.5% sponge, 24.5% cystoid, 34% mixed. Serous macular detachment was seen at 20.8% of eyes with mixed type macular edema. Of 53 eyes, 52.8% had ISOS and 50.9% had ELM defect. Visual acuity was better in patients using insulin than oral antidiabetic drugs. There was no statistically significant difference with visual acuity and macular edema type.

Conclusion: Central subfield thickness decreased and visual acuity increased after intravitreal injection of ranibizumab in cases of diabetic macular edema. The most important factor associated with worse visual acuity was persistence of ISOS/ELM defect. In addition, better visual acuity in patients who were on insulin treatment was related with better metabolic control. Keywords : Diabetic macular edema, intravitreal injection, ranibizumab