Abstract
Purpose:
Ranibizumab has become the gold standard in the treatment of diabetic macular edema (DME). We performed a retrospective study to examine the effectiveness of monthly intravitreal ranibizumab injections at 3 and 6 months. The study is approved by the local Ethical Committee.
Methods:
We analysed data of 111 consecutive patients who had DME with the central retinal thickness (CRT) greater than 400 microns in one or both eyes treated by monthly ranibizumab injections. Optical Coherence Tomography (OCT) images using Heidelberg Spectralis were taken at baseline prior to treatment, at 3 months, and at 6 months. The effect was graded as no significant improvement (less than 10% reduction of excess CRT), partial improvement (50% reduction), and significant improvement (more than 90% reduction of excess CRT).
Results:
In total, 155 eyes with DME, 89 male and 66 females with a median age of 65 years were included. Twenty four eyes were not included due to poor image quality. Following 3 consecutive monthly injections, 34% had no significant improvement, 45% has partial improvement and 21% has significant improvement. Of those with no improvement at 3 months, 87% did not show any further improvement despite another 3 injections. Whilst those patients who had a partial improvement at 3 months, only 18% had significant improvement by 6 months.
Conclusions:
Although ranibizumab has shown to be effective in the management of DME, in patients with thick retina (CRT > 400 microns) with partial improvement more injections need to be given to sustain the effect. However, if patients have not had an effect at 3 months then giving them more treatment is not likely to be beneficial and a different course of treatment should be considered.